Immunology laboratory established methods for determining the quality of sperm in the ejaculate using flow cytometry. Cytometric examination of ejaculate can be performed from the same semen sample from which the semen analysis was carried out. Additional sampling is not required.
Assessment of sperm apoptosis
Apoptosis is a process of programmed cell death. It is a natural process which involves gradual dying of sperm, DNA fragmentation and changes to the cell surface. Apoptotic cells are unable to fertilize the oocyte, but they are still moving in an early stage of apoptosis and it is difficult to distinguish such cell from truly live sperm cells under the microscope.
The ratio of apoptotic and live spermatozoa determines the quality of ejaculate. There must be at least 50% of the living sperm cells and less than 50% of apoptotic sperm cells in healthy semen. Probability of fertilization of oocytes increases with a higher proportion of live sperm in the semen.
High proportion of apoptotic spermatozoa is investigated in patients with infections, autoimmune diseases or pathologies of the urogenital tract. Therefore, patients with recurrent high number of apoptotic sperm are recommend treatment by an andrologist or immunologist.
Acrosomes of apoptotic sperm are often damaged. DNA fragmentation is more frequent as well. Apoptotic spermatozoa are less motile and therefore not suitable for IUI and IVF, in which sperm cells alone must actively penetrate the egg.
Sperm DNA fragmentation
Determining the number of sperm cells with fragmented DNA is performed by flow cytometry using the TUNEL method (terminal deoxynucleotide transferase dUTP Nick End Labeling). Color binds with an enzyme to the sperm DNA and it marks the damaged DNA. There is less than 20% of sperm cells with fragmented DNA in semen of good quality. 20-30% is a slightly increased value. More than 30% of sperm cells with DNA fragmentation is a high value.
The more spermatozoa with fragmented DNA are present in a semen sample, the lower the probability of successful fertilization of the oocyte. Examination of DNA fragmentation is recommended for patients with high numbers of apoptotic spermatozoa, patients after several unsuccessful IVF cycles (particularly when embryos developed poorly), or patients with diseases that may affect the quality of sperm.
Our clinic also provides cytometric examination of concentration of spermatozoa and leukocytes in the semen as well as determination of the number of sperm cells with poor acrosome or without acrosomal proteins. Acrosome quality is essential for natural fertilization of the oocyte.
We perform the examination of the presence of anti-sperm antibodies microscopically. Antibodies can significantly inhibit the movement of spermatozoa. Investigations are recommended especially in patients with reduced sperm motility (asthenozoospermia).
Causes of male infertility include malfunction of the immune system and autoimmunity. The laboratory also provides a set of blood tests, which allows the assessment of cellular and humoral immunity of patients and includes basic autoimmune markers as well.