Agglutination of spermatozoa is the agglutination of mobile spermatozoa among themselves (see Figure 1). The formation of conglomerates (joints) of cells disrupts their ability to move forward, which can lead to a decline in fertility. When spermatozoa are found agglutination, additional tests are performed to detect antisperm antibodies.
Fig. 1 - Agglutination of spermatozoa in the study of ejaculate.
It is important not to confuse such concepts as the aggregation of spermatozoa and the agglutination of spermatozoa. When sperm cells are aggregated, epithelial cells are adhered to cells, destroyed cells or mucus, or immobile spermatozoa are glued together. With agglutination sticking exclusively mobile spermatozoa. They can stick the head to the head, the flagellum to the flagellum or in a mixed version (see Figure 2).
Fig. 2 - Various variants of agglutination of spermatozoa.
Degrees of agglutination of spermatozoa
There are 4 degrees of agglutination of spermatozoa:
- Isolated. In one agglutinate (the mass of the glued cells) contains less than 10 spermatozoa, most of the cells are free.
- The average degree. In one agglutinate 10-50 cells, there are free spermatozoa.
- Significant degree. In agglutinate more than 50 cells, single spermatozoa are free.
- Heavy degree. Agglutinates are bound together, there are no free spermatozoa.
Agglutination does not necessarily indicate an immunological cause of infertility , but in order to confirm or exclude this cause, further studies are conducted to identify antisperm antibodies. Antisperm antibodies can be found on the spermatozoa themselves or in the biological fluids of men.
Identifies antibodies on spermatozoa.
MAR test or mixed antiglobulin reaction test
Inexpensive, simple in performance, sensitive, but less informative than a direct test with immune balls (see below).
The sample of the ejaculate is mixed either with latex beads coated with antispermal immunoglobulins (antibodies) or with similarly processed human erythrocytes. Further, anti-immunoglobulin is added to the suspension. In the presence of antispermal immunoglobulins on spermatozoa, anti-immunoglobulin glues (agglutinates) spermatozoa with globules. The appearance of such mixed conglomerates will speak of the presence of antibodies on spermatozoa. Non-antibody-coated cells will freely float between agglutinates.
Direct test with immune balls
With washed spermatozoa, particles coated with rabbit antihuman immunoglobulins are mixed against antisperm antibodies. If these particles begin to bind to mobile spermatozoa, then antisperm antibodies are present on the cell surface.
They are conducted for the detection of antisperm antibodies in biological fluids: seminal plasma, serum. Used in cases where the sperm in the ejaculate in question is not enough sperm (oligozoospermia), or too few mobile spermatozoa (astenozoospermia). In this case, washed donor spermatozoa are added to the diluted biological fluid, obviously not having antisperm antibodies. If these antibodies are present in the test fluid, they will bind to donor spermatozoa, after which a direct reaction can be made.
The threshold value is 50% of mobile spermatozoa coated with antibodies. If it is exceeded, problems with fertilization may occur both in vivo and in IVF.
The decrease in male fertility due to immune factors can be determined by several reasons.
Impaired hematotestick barrier
As the spermatozoa begin to form after puberty - that is, when the immune system has long functioned - their proteins are perceived as immunity as foreign. The hematotestick barrier separates blood cells from the cells of the reproductive system, preventing the immune cells from getting into the spermatic cord. When it is damaged, immune cells "read" information about sperm proteins and the body begins to produce antisperm antibodies (immunoglobulins). Damage to the hematotestick barrier is possible with:
- scrotal injury;
- after the transferred orchitis (inflammation of the testicles);
- some infections (chlamydia);
- overheating of the scrotum ( varicocele , cryptorchidism);
- chronic ischemia ( with inguinal hernia ).
Cross reactions with antigens of microorganisms
Antigens of some infectious agents, for example Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Proteus, have a molecular affinity with some surface proteins of spermatozoa. It can "mislead" the immune system. Other microorganisms, such as chlamydia, can attach to the surface of the sperm, triggering immune responses. In addition to the presence of the pathogen, the characteristics of the organism also have a value - a tendency to an excessive response of the immune system.
Agglutination of spermatozoa and detection of antisperm antibodies testify to the immune reasons for the decrease in male fertility. The reasons for this condition can be different, and a thorough andrological examination is needed to identify them. Only after this, it will be possible to understand whether autoimmune infertility is reversible, or whether it is necessary to resort to assisted reproductive technologies.
Sometimes for successful fertilization, there is enough intra-uterine sperm injection, in other cases more complicated methods, such as ICSI, may be required. In any case, the tactician of the further actions after revealing agglutination of spermatozoa should be offered by the attending physician.