Aniline blue staining as a marker of sperm chromatin defects associated with different semen characteristics discriminates between proven fertile and suspected infertile men

Abstract

A retrospective study of 49 men with proven fertility and 396 suspected infertile men was conducted with the primary objective of investigating the relationship between the nuclear maturity of sperm and male fertility. Acidic aniline blue staining was used to detect chromatin defects of sperm nuclei related to their nucleoprotein content as associated with DNA. The discriminant value of the percentage of unstained nuclei (= percentage of mature heads, MH) and of other semen characteristics, was analysed by a stepwise (forward) linear regression model. Semen characteristics that discriminated significantly between the two groups of subjects were, in descending order: (1) the percentage of normal sperm, (2) the percentage of amorphous heads, (3) the percentage of tapered heads, (4) semen volume, and (5) the percentage of MH. The discriminant value of each of the significant characteristics was studied by means of ROC-curves. MH had the best ROC-curve profile; its cut-off value was found to be equal to 70% (74.5 +/- 2.6% for the donor group versus 53.0 +/- 1.1% for the patient group). A simple infertility score (SIS) including MH, was built according to the cut-off values inferred from the ROC-curves. SIS allowed an overall satisfactory separation of the two groups (less than or equal to 4 = fertile, 5-6 = uncertainty zone, greater than 6 = infertile). Our results indicate that the addition of the evaluation of sperm head maturity to routine semen analysis improves the assessment of fertility in men.

CASA derived human sperm abnormalities: correlation with chromatin packing and DNA fragmentation

“…As a result, chromatin might be poorly packed in the last step of chromatin condensation process with an increase incidence of chromosomal aneuploidy. This explanation is supported by several studies demonstrating that spermatozoa with [35,36]. Spermatozoa with tapered heads were also reported to have a higher incidence of failed fertilization rates post ICSI due to probable chromatin abnormalities [22].…”

Sperm Chromatin Structure Assay: Its Clinical Use for Detecting Sperm DNA Fragmentation in Male Infertility and Comparisons With Other Techniques

“…The potential value of adding these techniques to standard infertility evaluations lies in their ability to identify abnormal chromatin condensation in morphologically normal and abnormal spermatozoa (Dadoune et al, 1988;Hofmann and Hilscher, 1991). Aniline blue selectively stains lysine-rich histones (Terquem and Dadoune, 1983) and has been used as a clinical assessment of sperm chromatin condensation and associated infertility (Auger et al, 1990). High percentages of aniline blue-stained spermatozoa were found in patients affected by severe teratozoospermia (Franken et al, 1999), asthenozoospermia (Colleu et al, 1988), varicocele, idiopathic infertility, and with a history of unilateral cryptorchidism (Foresta et al, 1992).…”

Sperm DNA Fragmentation is Significantly Increased in Those Men with Morphologically Abnormal Spermatozoa

“…Some head abnormalities are associated, with overall increase in head length with minor deviation in width, and the percentage coverage of acrosome in head is decreased, resulting in poorly packed chromatin and an increase in the incidence of chromosomal aneuploidy [47,48]. Therefore, spermatozoa with tapered heads were also reported to have a higher incidence of failed fertilization rates post ICSI due to chromatin abnormalities [49].…”