SCSA Diagnostics est le pionnier de l’analyse de l’ADN spermatique, en exploitant des recherches établies et des études cliniques en cours depuis plus de 25 ans pour réaliser l’un des tests de fragmentation de l’ADN spermatique les plus avancés disponibles.
Le développement du test SCSA a été présenté dans la revue renommée Science en décembre 1980.
Notez qu’il y a d’autres laboratoires qui offrent tests similaires au SCSA. Cependant, ce n’est pas le même test de précision que le test SCSA ®.
La fragmentation de l’ADN spermatique est l’une des causes paternelles les plus importantes d’échecs reproductifs répétés. Environ 20-30% des hommes qui consultent une clinique de fertilité ont un niveau de la fragmentation de l’ADN spermatique qui peut conduire des échecs de grossesse.
Spano et al. 2000 La ligne en pointillé montre le seuil clinique de la fragmentation de l’ADN spermatique et les chances de grossesse.
Certains auteurs ont publié que les échantillons de sperme contenant plus de 27-30% de spermatozoïdes avec des fragmentations de l’ADN (% de l’Indice de Fragmentation de l’ADN) ont 7 à 10 fois moins de chances de tomber enceintes par rapport sexuels ou IIU, et environ 1.5 à 2 fois moins de chances à travers FIV/ICSI.
Giwercman A et al. (2009 sous presse, Int. J. Androl) ont inclus 137 hommes de couples ayant une infertilité prouvée sans facteurs maternels connus et 137 hommes ayant une fertilité prouvée.
Dans les hommes avec des paramètres normaux du sperme (concentration, mobilité et morphologie du sperme), le risque d’infertilité a augmenté 5 fois avec des valeurs de l’Indice de fragmentation de l’ADN supérieures à 20%.
Cependant, si l’un des paramètres était anormal, le risque d’infertilité a augmenté 16 fois même avec des valeurs de l’Indice de fragmentation de l’ADN supérieures à 10%.
Les auteurs ont conclu que "l’Indice de fragmentation de l’ADN est un prédicteur de la probabilité de conception naturelle, même lorsque les paramètres spermatiques classiques se situent dans la plage normale. L'analyse SCSA complète la planification du traitement pour les couples présentant une infertilité prouvée."
Le dommage à l’ADN spermatique peut résulter de cinq mécanismes pathogènes différents (Perrin et al., 2011 ; Sakkas et Alvarez, 2010).
L’Indice de Fragmentation de l’ADN:
L’Indice de fragmentation de l’ADN (%) est la mesure de la fragmentation de l’ADN spermatique et un indicateur de la qualité spermatique.
Cellules à forte colorations de l’ADN : Le pourcentage de spermatozoïdes présentant de protéines centrales et des structures de chromatine anormales (des spermatozoïdes immatures)
Le test SCSA® est effectué à l’aide d’un dispositif laser appelé cytomètre en flux qui mesure 250 spermatozoïdes/seconde. Le résultat de test est basé sur la mesure d’environ 10,000 spermatozoïdes.
TEST DE DEPISTAGE : Particulièrement indiqué pour les couples avec un désir tant attendu d’avoir des enfants
TENTATIVES ECHOUEES D’IIU/FIV/ICSI
FAUSSES COUCHES RÉPÉTÉS
FAIBLE DÉVELOPPEMENT ET QUALITÉ EMBRYONNAIRE
STÉRILITÉ INEXPLIQUÉE: Des couples qui veulent avoir des enfants et ont des tests de diagnostics sans rien de remarquable
DES HOMMES SUJETS À UN STRESS OXYDATIVE ELEVE :Le test SCSA® est effectué à l’aide d’un dispositif laser appelé cytomètre en flux. Essentiellement, le cytomètre en flux mesure 250 spermatozoïdes/seconde avec une grande précision et fournit un résultat statiquement robuste basé sur des données de 2x 5000 spermatozoïdes par échantillon. La précision de cytomètre en flux couplée à la biochimie précise du test SCSA permet des mesures très précises de la chromatine du sperme et de l’intégrité de l’ADN.
Les cellules sont colorées avec un colorant fluorescent de l’ADN (acridine orange) et forcées à traverser un canal en verre dans une suspension liquide. Lorsque les cellules traversent le faisceau laser, la lumière du laser amène le colorant à émettre une lumière fluorescente d’une couleur spécifique. .
Dans le test SCSA®, en raison de la nature unique du colorant Acridine Orange, les spermatozoïdes qui émettent une fluorescence verte ont des niveaux indétectables d’ADN fragmenté, tandis que les spermatozoïdes qui émettent une fluorescence du jaune au rouge ont des niveaux modérés à élevés d’ADN fragmenté.
La fertilité masculine est traditionnellement examinée en utilisant de tests de sperme (spermogramme) qui registrent la concentration, la mobilité et la morphologie des spermatozoïdes. Cependant, de nombreuses études au cours de dernier demi-siècle montrent clairement que ces paramètres ne prédisent pas la grossesse, car des hommes fertiles et infertiles ont des valeurs qui se chevauchent (à l’exception de l’azoospermie). Les spermogrammes classiques sont des mesures en microscopie des facteurs externes des spermatozoïdes, tandis que le test SCSA mesure les facteurs internes du noyau qui ne peuvent pas être mesurés en utilisant un microscope optique.
Le test SCSA est un test très précis qui nécessite d’un cytomètre en flux inaccessible à la plupart des cliniques de fertilité en raison des coûts d’investissements élevés et d’un personnel qualifié.
Par conséquent, les échantillons de sperme prélevés chez vous ou au domicile du patient peuvent être cryoconservés de manière native.
Vous pouvez nous informer par e-mail sur un transport souhaité. Nous vous enverrons ensuite un récipient pré-refroidi ; les échantillons de sperme sont stockés et renvoyés à notre laboratoire.
Le rapport SCSA sera à votre disposition via un site web sécurisé environ 4 jours ouvrables après l’arrivée de l’échantillon à notre laboratoire.
Collecte et traitement des échantillons :
Il devrait être obtenu après 24-48 heures d’abstinence en se masturbant dans des récipients à échantillons en plastique stériles. Après la liquéfaction de l’échantillon, la concentration, la mobilité et la morphologie des spermatozoïdes sont déterminées. Notez les paramètres sur la lettre de voiture.
La concentration de sperme ne doit pas tomber en dessous de 500,000/ml. Sinon, des résultats non concluants peuvent survenir.
La cryoconservation devrait avoir lieu au plus tard 1 heure après la livraison, car l’Indice de fragmentation de l’ADN peut être falsifié après une période d’attente plus longue.
La cryoconservation des échantillons :
Les échantillons doivent être congelés le plus tôt possible après la liquéfaction afin de minimiser l’exposition à l’air, qui peut causer des dommages causés par les espèces réactives d’oxygène.
Préparez 2 cryotubes (flacons de 1-2ml) : L’étiquette avec le nom du patient et la date de la collecte d’échantillon.
Congélation instantanée :
Pipette 0.25ml ou plus de l’éjaculat natif liquéfié dans chaque cryotube.
Des cryoprotecteurs ne sont pas nécessaires !
Placez les flacons bien fermés en position verticale dans le support métallique et places-le directement dans le récipient cryogénique pré-refroidi. Le récipient doit être fermé rapidement.
Le récipient est fermé avec l’attache de câble fourni et placé dans le récipient en plastique, auquel le bordereau d’expédition est attaché afin qu’il soit clairement visible.
Remarque : Si la concentration de sperme est suffisante, moins de 0.5 ml (deux parties aliquotes de 0.25 ml) d’éjaculation doit être suffisant pour le test SCSA®. Pour réaliser le test nous avons besoin de deux parties aliquotes de 0.20ml avec une concentration >0.5m/ml.
S’il vous plaît, contactez notre laboratoire si vous avez des questions sur le volume requis d’un échantillon d’une concentration spécifique.
Envoi des échantillons :
Nous expédions un récipient pré-réfrigéré. Les récipients stockent l’azote liquide dans une sorte "d’éponge" à l’intérieur du récipient et assurent la sécurité du transport de vos échantillons cryoconservés en azote en phase gazeuse. La basse température dans le récipient peut être maintenue pendant 7 jours. Il est donc important de le renvoyer le plus tôt possible en utilisant l’étiquette d’expédition fournis.
Dans l’espace entre le récipient et la boîte d’expédition il y a une enveloppe avec un attache de câble et un support d’ampoule. Il contient également une étiquette d’expédition et un manchon correspondant qui doivent être attachés au récipient pour l’expédition de retour.
Il fait très froid (-196°C) à l’intérieur du récipient. À fin d’éviter les engelures, vous devez porter des gants lorsque vous touchez tout ce qui se trouve dans le récipient.
Le test SCSA divise les spermatozoïdes en cinq populations :
Le pourcentage de spermatozoïdes avec chromatine immature. Les spermatozoïdes de Cellules à forte colorations de l’ADN présentent moins de condensation de la chromatine, en augmentant la capacité de coloration de l’ADN. Certaines études ont montré que si le pourcentage de Cellules à forte colorations de l’ADN est supérieur à 36%, aucune grossesse est survenue (Menezo).
Les valeurs de l’Indice de fragmentation de l’ADN sont divisées en quatre catégories statistiques et peuvent fournir les prévisions suivantes :
Indice de fragmentation de l’ADN < 15% = des résultats de grossesse de très bons à bons
Indice de fragmentation de l’ADN de > 15% à < 25% = des résultats de grossesse de bons à modérés.
Indice de fragmentation de l’ADN de > 25% à < 40% = des résultats de grossesse de modérés à pauvre
Indice de fragmentation de l’ADN 40% = des résultats de grossesse très mauvais Toutes les données doivent être compris sans l’influence de facteurs maternelles. De plus, le résultat montre une représentation graphique du pourcentage d’Indice de fragmentation de l’ADN et le pourcentage de Cellules à forte colorations de l’ADN.
Le graphique montre que 76% des spermatozoïdes mesurés ne montrent aucune fragmentation de l’ADN et 24% montrent une fragmentation de l’ADN de modérée à élevée (l’Indice de fragmentation de l’ADN = 24%). Il est possible de concevoir naturellement ou à l’aide d’une IIU.
Les données actuelles montrent que la probabilité d’une grossesse réussie est significativement plus baisse lorsque la proportion des spermatozoïdes avec de l’ADN fragmenté est > 25%. Cependant, un Indice de fragmentation de l’ADN > 25% n’exclut pas la possibilité de grossesse. Le seuil de 25% est un seuil statistique. Si un homme présente un Indice de fragmentation de l’ADN constant de > 25%, il est placé dans un groupe statistique qui a montré dans des essais cliniques qu’il met plus de temps à atteindre une grossesse naturelle et plus de cycles de FIV. Un taux accru des fausses couches est associé à cela ou la grossesse ne se produira pas du tout.
Évaluation de la qualité de l’ADN spermatique
Étant donné que l’Indice de fragmentation de l’ADN et les Cellules à forte colorations de l’ADN sont dans la plage normale, la grossesse est possible naturellement ou par insémination (en ignorant les facteurs du partenaire qui affectent la fertilité)Cela signifie que l’ADN spermatique présente une stabilité élevée
L’Indice de fragmentation de l’ADN est fortement augmenté. Cela signifie que l’ADN spermatique est très fragile et tends vers la fragmentation de l’ADN.
La stabilisation de l’ADN peut être obtenue par :
Il peut être nécessaire de passer de l’IIU à la FIV/ICSI pour augmenter les chances d’un résultat positif de grossesse
The histogram shows the DFI (DNA Fragmentation Index) measured in a semen sample.
DFI scores are classified into four statistical categories and can predict the following (ignoring partner factors affecting fertility):
< 15% DFI = Very good to good pregnancy outcomes
> 15% to < 25% DFI = Good to moderate pregnancy outcomes
> > 25% to < 40% DFI = Moderate to poor pregnancy outcomes
> 40% DFI = Very bad outcome of pregnancy
If the %DFI is above 25%, the current literature recommends:
On croit que l’ovule est capable de réparer certains niveaux de dommages de l’ADN. Les niveaux modérés à élevés de la fragmentation de l’ADN trouvés dans le spermatozoïde fluorescent rouge dépassent probablement la capacité de réparation de l’ADN de l’ovule.
Marcos Mesequer et al. ont découvert qu’après le prélèvement de l’ovule, chaque augmentation de 10% de l’Indice de fragmentation de l’ADN a augmenté la probabilité de ne pas tomber enceinte d’un facteur de 1.31. En comparaison, cet effet n’a pas été observé lors de l’utilisation d’ovocytes de donneurs, ce qui indique une capacité de réparation plus élevée en ce qui concerne la fragmentation de l’ADN des ovocytes jeunes.
Si l’Indice de fragmentation est élevé, nous recommandons :
S’il y a un facteur de risque, répéter le test SCSA est recommandé 3 mois après la suppression/correction du facteur de risque pour évaluer l’impact.
Exemples :
L’abstinence de nicotine (84 jours après) :
La chirurgie de varicocèle (3 mois après) :
Arrêt de l’exposition aux pesticides (3 mois après) :
Le coût de test est de €295. Il n’est actuellement pas couvert par les plans de santé.
L’envoi de vos échantillons à notre laboratoire est gratuit.
Pour les valeurs de l’Indice de fragmentation >30%, nous vous offrons un deuxième test de contrôle gratuit, qui devrait normalement avoir lieu 3 mois après le premier test.
Fragmentation of sperm DNA is one of the most important paternal causes of repeated reproductive failure. About 20-30% of men who attend a fertility clinic have a level of sperm DNA fragmentation that can lead to pregnancy failure.
Spano et al. 2000 The dashed line shows the clinical threshold for sperm DNA fragmentation and pregnancy chances
Some authors have published that semen samples containing more than 27-30% sperm with DNA fragmentations (DNA Fragmentation Index, %DFI) are 7-10 times less likely to get pregnant through intercourse or IUI, and one around 1.5 -2.0 times lower chance through IVF/ICSI
Giwercman A et al. (2009 in press, Int. J. Androl) included 137 men from couples with proven infertility with no known maternal factors and 137 men with proven fertility
In men with normal semen parameters (sperm concentration, motility and morphology), the risk of infertility was increased 5-fold with DFI values above 20%.
However, if any of the semen parameters were abnormal, the risk of infertility was increased 16-fold even with DFI values above 10%
The authors concluded that “DFI is a predictor of the likelihood of natural conception, even when classic semen parameters are within the normal range. The SCSA analysis complements treatment planning for couples with proven infertility.”
Sperm DNA integrity is continuously challenged by endogenous and exogenous factors, although different mechanisms of repairing and protecting against this damage are active in human cells (Hoeijmakers, 2009). This is particularly relevant in germ cells, which have to preserve DNA integrity to pass the genome to the next generation. In these cells, DNA double-strand breaks are physiologically induced during spermatogenesis and spermiogenesis to facilitate meiotic crossover and histone– protamine substitution, respectively (Rathke et al., 2014). Apart from this first ‘physiological’ DNA damage, other exogenous and endogenous factors could affect DNA integrity during sperm maturation and storage in the epididymis (Moustafa et al., 2004; Ramos et al., 2004; Sakkas et al., 2002). Thus, DNA integrity is constantly at risk and its assessment could be a fundamental step in the evaluation of sperm functional competence (Lewis et al., 2008). Hence, sperm DNA damage evaluation could be crucial for both infertility diagnosis and prediction of ART success. In the setting of IVF this evaluation plays a peculiar role because the natural selection barriers of conception are bypassed, increasing the possibility of spermatozoa with significant DNA damage transmitting the genetic aberrations to the newborn (Host et al., 2000). Thus, several trials have evaluated the predictive role of sperm DNA damage for either ART outcome or sperm selection.
DFI (DNA Fragmentation Index) :
Percentage of sperm with DNA fragmentation
HDS (High DNA Stainability Cells): Percentage of sperm with abnormal core proteins and chromatin structures (immature sperm)
The SCSA® test is performed using a laser-based device called a flow-cytometer which measures 250 sperm/second. The test result is based on the measurment of around 10,000 sperm.
Sperm DNA damage can result from five different pathogenic mechanisms (Perrin et al., 2011; Sakkas and Alvarez, 2010).
The SCSA® test is performed using a laser-based device called a flow cytometer. Essentially, the flow cytometer measures 250 sperm/s with high precision, providing a statistically robust result based on data from 2x 5000 sperm per sample. The precision of flow cytometry coupled with the precise biochemistry of the SCSA test provides highly accurate measurements of sperm chromatin and DNA integrity.
The cells are stained with a fluorescent DNA stain (acridine orange) and then forced through a glass channel in a liquid suspension. When the cells pass the laser beam, the laser light causes the dye to emit fluorescent light of a specific color.
In the SCSA® test, due to the unique nature of the Acridine Orange dye, sperm that emit green fluorescence have undetectable levels of fragmented DNA, while sperm that emit yellow to red florescence have moderate to high levels of fragmented DNA.
The SCSA test is a two-fold simultaneous flow cytometry measure of
in thousands of sperm in a fresh or frozen/thawed semen sample.
The extent of DNA strand breaks and abnormality of chromatin structure are related to male factor fertility, including time to couple pregnancy, IVF embryo quality, miscarriage, or infertility.
Male fertility is classically addressed by semen tests that include sperm density, motility and morphology. However, numerous studies over the past half century clearly show that, except for absence of sperm, these parameters do not predict pregnancy since fertile and infertile men have overlapping values. The classical semen tests are light microscope measures of external sperm factors while the SCSA test are measures of the internal nuclear factors not visible by light
microscopy.
The SCSA test is a high precision test that requires a flow cytometer which due to the need of a high capital expense and a trained technician is not amenable to most infertility clinics. Thus, semen samples collected, as per detailed instructions, in a clinic or in a patients’ home, can be flash frozen in a LN 2 dry shipper tank.(See support protocol 1).
Clinics can then send us an email informing us. A pre-cooled LN 2 shipper is then sent to the clinic and the semen samples are flash frozen and the LN 2 shipper then returned to a SCSA diagnostic testing lab.
Some clinics send frozen semen samples in well insulated dry ice containers.
SCSA clinical data are then sent via a secure WEB site to the physician or patient that ordered the test.
There are five main populations of sperm identified by the SCSA® test:
Our SCSA clinical report lists four statistical categories of fertility potential. These were derived from a comprehensive study of male fertility potential without medical intervention and have been confirmed in additional studies.
< 15% DFI = Excellent to good pregnancy outcomes (excluding female infertility factors)
> 15% to < 25% DFI = good to fair pregnancy outcomes
> 25% to < 40% DFI = fair to poor pregnancy outcomes
> 40% DFI = Very poor pregnancy outcomes
Furthermore, the finding shows a graphical representation of the %DFI (DNA Fragmentation Index) and the %HDS (high DNA stainability)
The graph shows that 76% of the measured sperm shows no DNA fragmentation and 24% shows medium-high DNA fragmentation (DFI= 24%). Pregnancy naturally or with the help of an IUI is possible.
Current data shows that the probability of a successful pregnancy is significantly lower when the proportion of sperm with fragmented DNA is > 25%. Nevertheless, a DFI > 25% does not rule out a normal pregnancy. The 25% threshold is a statistical threshold. Therefore, if a man has a constant DFI >25%, he will be placed in a statistical group of men who have been shown in clinical trials to take longer to achieve natural pregnancy and more IVF cycles. An increased rate of spontaneous abortions is associated with this or pregnancy does not occur at all.
The ovum is believed to be able to repair a certain amount of DNA damage.
Moderate to high levels of DNA fragmentation (DFI) found in the red fluorescent sperm likely exceed the egg’s DNA repair capacity.
Marcos Meseguer et al found that when oocytes from patients were taken, for every 10% increase in DFI, there was a 1.31 times increase in probability of not achieving pregnancy. Whereas, the same was not seen when donor oocytes were employed suggesting the higher capability of young oocytes to repair sperm DNA damage.
REPEATED IUI / IVF / ICSI FAILURE : The reason behind the unsuccessful attempts at IUI/IVF/ICSI can be identified and managed
REPEATED MISCARRAGE : An explanation for repeated spontaneous abortions (RPL, repeated miscarriage) could be found and guided
POOR EMBRYO DEVELOPMENT AND QUALITY : The reason behind poor embryo quality could be the fragmented sperm DNA which could be corrected before the next treatment
MEN AT RISK FOR HIGHER OXIDATIVE STRESS:INITIAL SCREENING TEST : Especially for couples who have been attempting pregnancy for a long time to identify the best management strategy
UNEXPLAINED INFERTILITY : Couples desiring children with all normal diagnostic tests
In cases of high DFI, we suggest:
When a risk factor is identified, after avoidance / correction of the risk factor a repeat SCSA test after 3 months is advised.
Yes. We offer a SCSA test at half the cost for controlling the effect of avoidance / correction of a risk factor.
Please find a few examples below:
After quitting smoking for 84 days
3 months after varicocele correction surgery :
3 months after stopping pesticide exposure:
After 24-48 hours of abstinence, the samples should be taken by masturbation into sterile plastic sample containers. After liquefaction of the sample, the sperm concentration, motility and morphology are determined.
Cryopreservation should take place no more than 1 hour after delivery, since the DFI can be falsely raised after a longer waiting period.
Flash-freezing: Freeze 0.25mL or more of liquefied native ejaculate in 1-2mL cryovials. Cryoprotectants is not required! (Please freeze 2 cryovials per patient)
Samples should be frozen as soon as possible after liquefaction to minimize exposure to air, which can cause damage caused by reactive oxygen species.Cryovials should be tightly capped, labeled with two identifiers (e.g. name and date of birth) and placed in an upright position directly into the pre-chilled cryo-container. The container must be closed quickly.
Note: Cryoprotectants are not needed since quick-frozen sperm give the clearest SCSA® data. This feature is unique to mammalian sperm cells due to the highly condensed, crystalline nature of the nuclei.
Note: If the sperm concentration is adequate, less than 0.5 mL (two 0.25 mL aliquots) of semen may be sufficient for the SCSA® test. To perform the test, we require two 0.20 mL aliquots with a concentration of >0.5 million/ml. Please contact our laboratory if you have questions pertaining to the volume necessary for a sample of a certain concentration.
We ship a pre-chilled dry shipper. Dry shippers store the liquid nitrogen in porous material and thus ensure the safe transport of your cryopreserved samples in the nitrogen gas phase.
The low temperature in the container can be maintained for 7 days. It is therefore important to send it back as soon as possible using the mailed/supplied shipping label.
Note: liquid nitrogen is adsorbed by special materials inside the shipping container. Even if they are turned upside down during transport, no liquid nitrogen will leak out. Dry shippers are not considered dangerous.
After receiving the sample(s) in our laboratory, we need 4 working days to create a report, which we will send to you.
The cost of the test is 295 Euro.
* Samples are shipped in a pre-cooled shipper that we can provide either at ambient or pre-chilled temperatures. The pre-cooled shipper will be sent to the centre where you have provided your sample for the centre to ship it to us.
The test at present is not covered by the insurance.
Please write us an email to contact@scsalab.com and after contacting you, we will send toy a dry shipper for the patient sample to be sent to us.
Fragmentation of sperm DNA is one of the most important paternal causes of repeated reproductive failure. About 20-30% of men who attend a fertility clinic have a level of sperm DNA fragmentation that can lead to pregnancy failure.
Spano et al. 2000 The dashed line shows the clinical threshold for sperm DNA fragmentation and pregnancy chances
Some authors have published that semen samples containing more than 27-30% sperm with DNA fragmentations (DNA Fragmentation Index, %DFI) are 7-10 times less likely to get pregnant through intercourse or IUI, and one around 1.5 -2.0 times lower chance through IVF/ICSI
Giwercman A et al. (2009 in press, Int. J. Androl) included 137 men from couples with proven infertility with no known maternal factors and 137 men with proven fertility
In men with normal semen parameters (sperm concentration, motility and morphology), the risk of infertility was increased 5-fold with DFI values above 20%.
However, if any of the semen parameters were abnormal, the risk of infertility was increased 16-fold even with DFI values above 10%
The authors concluded that “DFI is a predictor of the likelihood of natural conception, even when classic semen parameters are within the normal range. The SCSA analysis complements treatment planning for couples with proven infertility.”
Sperm DNA integrity is continuously challenged by endogenous and exogenous factors, although different mechanisms of repairing and protecting against this damage are active in human cells (Hoeijmakers, 2009). This is particularly relevant in germ cells, which have to preserve DNA integrity to pass the genome to the next generation. In these cells, DNA double-strand breaks are physiologically induced during spermatogenesis and spermiogenesis to facilitate meiotic crossover and histone– protamine substitution, respectively (Rathke et al., 2014). Apart from this first ‘physiological’ DNA damage, other exogenous and endogenous factors could affect DNA integrity during sperm maturation and storage in the epididymis (Moustafa et al., 2004; Ramos et al., 2004; Sakkas et al., 2002). Thus, DNA integrity is constantly at risk and its assessment could be a fundamental step in the evaluation of sperm functional competence (Lewis et al., 2008). Hence, sperm DNA damage evaluation could be crucial for both infertility diagnosis and prediction of ART success. In the setting of IVF this evaluation plays a peculiar role because the natural selection barriers of conception are bypassed, increasing the possibility of spermatozoa with significant DNA damage transmitting the genetic aberrations to the newborn (Host et al., 2000). Thus, several trials have evaluated the predictive role of sperm DNA damage for either ART outcome or sperm selection.
DFI (DNA Fragmentation Index) :
Percentage of sperm with DNA fragmentation
HDS (High DNA Stainability Cells): Percentage of sperm with abnormal core proteins and chromatin structures (immature sperm)
The SCSA® test is performed using a laser-based device called a flow-cytometer which measures 250 sperm/second. The test result is based on the measurment of around 10,000 sperm.
Sperm DNA damage can result from five different pathogenic mechanisms (Perrin et al., 2011; Sakkas and Alvarez, 2010).
The SCSA® test is performed using a laser-based device called a flow cytometer. Essentially, the flow cytometer measures 250 sperm/s with high precision, providing a statistically robust result based on data from 2x 5000 sperm per sample. The precision of flow cytometry coupled with the precise biochemistry of the SCSA test provides highly accurate measurements of sperm chromatin and DNA integrity.
The cells are stained with a fluorescent DNA stain (acridine orange) and then forced through a glass channel in a liquid suspension. When the cells pass the laser beam, the laser light causes the dye to emit fluorescent light of a specific color.
In the SCSA® test, due to the unique nature of the Acridine Orange dye, sperm that emit green fluorescence have undetectable levels of fragmented DNA, while sperm that emit yellow to red florescence have moderate to high levels of fragmented DNA.
The SCSA test is a two-fold simultaneous flow cytometry measure of
in thousands of sperm in a fresh or frozen/thawed semen sample.
The extent of DNA strand breaks and abnormality of chromatin structure are related to male factor fertility, including time to couple pregnancy, IVF embryo quality, miscarriage, or infertility.
Male fertility is classically addressed by semen tests that include sperm density, motility and morphology. However, numerous studies over the past half century clearly show that, except for absence of sperm, these parameters do not predict pregnancy since fertile and infertile men have overlapping values. The classical semen tests are light microscope measures of external sperm factors while the SCSA test are measures of the internal nuclear factors not visible by light
microscopy.
The SCSA test is a high precision test that requires a flow cytometer which due to the need of a high capital expense and a trained technician is not amenable to most infertility clinics. Thus, semen samples collected, as per detailed instructions, in a clinic or in a patients’ home, can be flash frozen in a LN 2 dry shipper tank.(See support protocol 1).
Clinics can then send us an email informing us. A pre-cooled LN 2 shipper is then sent to the clinic and the semen samples are flash frozen and the LN 2 shipper then returned to a SCSA diagnostic testing lab.
Some clinics send frozen semen samples in well insulated dry ice containers.
SCSA clinical data are then sent via a secure WEB site to the physician or patient that ordered the test.
There are five main populations of sperm identified by the SCSA® test:
Our SCSA clinical report lists four statistical categories of fertility potential. These were derived from a comprehensive study of male fertility potential without medical intervention and have been confirmed in additional studies.
< 15% DFI = Excellent to good pregnancy outcomes (excluding female infertility factors)
> 15% to < 25% DFI = good to fair pregnancy outcomes
> 25% to < 40% DFI = fair to poor pregnancy outcomes
> 40% DFI = Very poor pregnancy outcomes
Furthermore, the finding shows a graphical representation of the %DFI (DNA Fragmentation Index) and the %HDS (high DNA stainability)
The graph shows that 76% of the measured sperm shows no DNA fragmentation and 24% shows medium-high DNA fragmentation (DFI= 24%). Pregnancy naturally or with the help of an IUI is possible.
Current data shows that the probability of a successful pregnancy is significantly lower when the proportion of sperm with fragmented DNA is > 25%. Nevertheless, a DFI > 25% does not rule out a normal pregnancy. The 25% threshold is a statistical threshold. Therefore, if a man has a constant DFI >25%, he will be placed in a statistical group of men who have been shown in clinical trials to take longer to achieve natural pregnancy and more IVF cycles. An increased rate of spontaneous abortions is associated with this or pregnancy does not occur at all.
The ovum is believed to be able to repair a certain amount of DNA damage.
Moderate to high levels of DNA fragmentation (DFI) found in the red fluorescent sperm likely exceed the egg’s DNA repair capacity.
Marcos Meseguer et al found that when oocytes from patients were taken, for every 10% increase in DFI, there was a 1.31 times increase in probability of not achieving pregnancy. Whereas, the same was not seen when donor oocytes were employed suggesting the higher capability of young oocytes to repair sperm DNA damage.
REPEATED IUI / IVF / ICSI FAILURE : The reason behind the unsuccessful attempts at IUI/IVF/ICSI can be identified and managed
REPEATED MISCARRAGE : An explanation for repeated spontaneous abortions (RPL, repeated miscarriage) could be found and guided
POOR EMBRYO DEVELOPMENT AND QUALITY : The reason behind poor embryo quality could be the fragmented sperm DNA which could be corrected before the next treatment
MEN AT RISK FOR HIGHER OXIDATIVE STRESS:INITIAL SCREENING TEST : Especially for couples who have been attempting pregnancy for a long time to identify the best management strategy
UNEXPLAINED INFERTILITY : Couples desiring children with all normal diagnostic tests
In cases of high DFI, we suggest:
When a risk factor is identified, after avoidance / correction of the risk factor a repeat SCSA test after 3 months is advised.
Yes. We offer a SCSA test at half the cost for controlling the effect of avoidance / correction of a risk factor.
Please find a few examples below:
After quitting smoking for 84 days
3 months after varicocele correction surgery :
3 months after stopping pesticide exposure:
After 24-48 hours of abstinence, the samples should be taken by masturbation into sterile plastic sample containers. After liquefaction of the sample, the sperm concentration, motility and morphology are determined.
Cryopreservation should take place no more than 1 hour after delivery, since the DFI can be falsely raised after a longer waiting period.
Flash-freezing: Freeze 0.25mL or more of liquefied native ejaculate in 1-2mL cryovials. Cryoprotectants is not required! (Please freeze 2 cryovials per patient)
Samples should be frozen as soon as possible after liquefaction to minimize exposure to air, which can cause damage caused by reactive oxygen species.Cryovials should be tightly capped, labeled with two identifiers (e.g. name and date of birth) and placed in an upright position directly into the pre-chilled cryo-container. The container must be closed quickly.
Note: Cryoprotectants are not needed since quick-frozen sperm give the clearest SCSA® data. This feature is unique to mammalian sperm cells due to the highly condensed, crystalline nature of the nuclei.
Note: If the sperm concentration is adequate, less than 0.5 mL (two 0.25 mL aliquots) of semen may be sufficient for the SCSA® test. To perform the test, we require two 0.20 mL aliquots with a concentration of >0.5 million/ml. Please contact our laboratory if you have questions pertaining to the volume necessary for a sample of a certain concentration.
We ship a pre-chilled dry shipper. Dry shippers store the liquid nitrogen in porous material and thus ensure the safe transport of your cryopreserved samples in the nitrogen gas phase.
The low temperature in the container can be maintained for 7 days. It is therefore important to send it back as soon as possible using the mailed/supplied shipping label.
Note: liquid nitrogen is adsorbed by special materials inside the shipping container. Even if they are turned upside down during transport, no liquid nitrogen will leak out. Dry shippers are not considered dangerous.
After receiving the sample(s) in our laboratory, we need 4 working days to create a report, which we will send to you.
The cost of the test is 295 Euro.
* Samples are shipped in a pre-cooled shipper that we can provide either at ambient or pre-chilled temperatures. The pre-cooled shipper will be sent to the centre where you have provided your sample for the centre to ship it to us.
The test at present is not covered by the insurance.
Please write us an email to contact@scsalab.com and after contacting you, we will send toy a dry shipper for the patient sample to be sent to us.