Semen Analysis: Immunologic Examination for Infertility Test

The immunologic analysis of semen is a component of the investigation of infertility, and it aims to assess the presence of antibodies that may affect sperm function. Antisperm antibodies (ASA) are immune system proteins that can target and potentially impair sperm function, leading to fertility issues. There are different methods and tests employed in immunologic analysis of semen to detect the presence of these antibodies:

1. Direct Sperm Antibody Test (SAT): This test directly measures the presence of antibodies on the surface of sperm. It involves incubating sperm with a substance that binds to antibodies, and the resulting reaction can be detected under a microscope.
2. Indirect Sperm Antibody Test (ISAT): This test detects antibodies in the seminal plasma (the fluid part of semen). Serum (blood) is mixed with sperm, and if antibodies are present, they will attach to the sperm. The remaining solution is then tested for the presence of antibodies.
3. Mixed Antiglobulin Reaction (MAR) Test: This is another indirect method where sperm are mixed with antibodies that can bind to human antibodies. After washing, the solution is tested to see if any antibodies are attached to the sperm.
4. Immunobead Binding Test: In this test, latex beads coated with antibodies are mixed with semen. If there are antisperm antibodies in the semen, they will bind to the latex beads. The bead-sperm complexes can be detected and quantified.
5. Flow Cytometry: This technique uses a flow cytometer to analyze individual sperm cells tagged with fluorescent markers. It can provide information on the percentage of sperm affected by antibodies and the degree of binding.

It's important to note that the presence of antisperm antibodies does not always correlate with infertility, and the impact of antibodies on fertility can vary. Additionally, the causes of antisperm antibodies can be diverse, including infections, trauma, or autoimmune disorders. Treatment options may include assisted reproductive technologies (ART) such as in vitro fertilization (IVF) or intrauterine insemination (IUI).

Antisperm Antibodies

The role of antisperm antibodies in the etiology of male infertility remains a subject of debate. Immunological assessments conducted on seminal fluid encompass the mixed antiglobulin reaction (MAR test) and the immunobead test.

Antibodies directed against sperm have the capacity to either immobilize or terminate them, impeding their journey through the cervix to reach the ovum. These antibodies can be examined in the serum, seminal fluid, or cervical mucus. In cases where antibodies are affixed to the head of the sperm, they hinder the sperm from penetrating the egg. Conversely, when antibodies are attached to the tail of the sperm, they impede its motility. This intricate interplay underscores the potential impact of antisperm antibodies on various aspects of sperm function, contributing to the complexities surrounding male infertility.

SpermMAR™ test

The SpermMAR™ test is designed to identify IgG and IgA antibodies targeting the surface of sperm in a semen sample. In the direct SpermMAR™ IgG test, a drop of fresh and unwashed semen is combined with IgG-coated latex particles and anti-human immunoglobulin on a glass slide. A thorough examination of at least 200 motile spermatozoa is conducted. If antibodies are present on the sperm surface, antihuman immunoglobulin binds IgG-coated latex particles to the IgG on the spermatozoa surface. This results in the attachment of latex particles to spermatozoa, observable as motile, swimming spermatozoa with attached particles. Conversely, in the absence of antibodies on the sperm surface, swimming spermatozoa without attached particles are observed, and the latex particles demonstrate clumping due to the binding of their IgG to antihuman immunoglobulin.

In the direct SpermMAR™ IgA test, a drop of fresh unwashed semen and IgA-coated latex particles are mixed on a glass slide. The latex particles bind to spermatozoa if they are coated with IgA antibodies.

The indirect SpermMAR™ tests involve examining fluid without spermatozoa (e.g., serum) for the presence of antisperm antibodies. Initially, antibodies are bound to donor spermatozoa, which are then mixed with the fluid under analysis. These antibodies are subsequently detected as described in the direct tests.

A minimum count of 200 motile spermatozoa is recommended. If more than 50% of spermatozoa exhibit attached latex particles, an immunological issue is likely. This meticulous evaluation through the SpermMAR™ test provides valuable insights into the presence of antisperm antibodies, aiding in the diagnosis of potential immunological factors impacting sperm function.

Immunobead test

The Immunobead test is a diagnostic method aimed at identifying antibodies affixed to the surface of spermatozoa. This is achieved by utilizing immunobeads, which are plastic particles with attached anti-human immunoglobulin (IgG, IgA, or IgM). The procedure involves counting the percentage of motile spermatozoa with two or more attached immunobeads within a sample of 200 motile spermatozoa. An abnormal result is indicated when more than 50% of spermatozoa exhibit attached beads.

This meticulous assessment provides valuable information about the presence of antibodies on the surface of sperm, contributing to a comprehensive understanding of potential immunological factors affecting sperm function. The Immunobead test serves as a crucial tool in the diagnostic arsenal for evaluating male fertility and identifying abnormalities in the immune response against spermatozoa.