Detection of antisperm antibodies on the surface of motile spermatozoa. Comparison of the immunobead binding technique (IBT) and the mixed antiglobulin reaction (MAR)

Basis, diagnosis and treatment of immunological infertility in men

Sperm-reactive antibodies (SpAb) are found attached to sperm, or present in serum or seminal fluid, in approximately 6% of men presenting with infertility. Data supports their pathophysiological role in some cases by the interference with sperm motility and/or sperm-egg interaction. The occurrence of SpAbs may follow disruption of either the cellular barrier separating sperm antigens from the immune system (e.g. testis trauma or obstruction to sperm outflow), or to dysregulation of normal immunosuppressive activities within the male reproductive tract. The epididymis is likely to be the key site of antibody generation, especially in the setting of obstruction. Detection methods are all based on the detection of Ig isotypes rather than specific antibody-antigen interactions, which limits their usefulness. Treatment options in the past (immunosuppression, intrauterine insemination, conventional in vitro fertilization) have been superceded by intracytoplasmic sperm injection (ICSI) which appears to circumvent all adverse effects of male SpAbs.

Detection of antisperm antibodies on the surface of living spermatozoa using flow cytometry: preliminary study

OBJECTIVE

To assess the use of flow cytometry (FCM) analysis of living spermatozoa subjected to indirect immunofluorescence staining with the mouse anti-human immunoglobulin (Ig)G monoclonal antibodies (FCM test) as an objective method for the detection of antisperm antibodies in semen and serum.

DESIGN

The comparative studies were conducted with the direct and indirect mixed antiglobulin reaction (MAR) and FCM test performed by FCM analyzer FACSCAN (Becton Dickinson Immunocytometry Systems, Mountain View, CA).

SETTING

Clinical infertile service.

PATIENTS

Seventy-six semen and 20 sera samples of infertile patients were analyzed.

RESULTS

For IgG in semen there was a highly significant correlation between the direct MAR and FCM test. Six of 12 IgG-positive samples revealed also IgA, and just one sample, which showed negative MAR, was positive for IgM in FCM test. Flow cytometry test and indirect MAR showed also a highly significant correlation of the results of IgG detection in sera.

CONCLUSIONS

Flow cytometry test may be used to verify that IgG antisperm antibodies are on the surface of living spermatozoa either retrieved directly from an ejaculate or after exposure to serum and to determine proportion of antisperm antibodies-positive spermatozoa, titer, and quantity of antibodies bound to the cell surface.

Comparison of mixed antiglobulin reaction and direct immunobead test for detection of sperm-bound antibodies in subfertile males

OBJECTIVE

To compare two methods of detection of surface bound antibodies on spermatozoa from subfertile males.

DESIGN

Prospective comparison of direct mixed antiglobulin reaction (MAR) for immunoglobulin (Ig)G with direct immunobead test (IgG and IgA) applied to spermatozoa from male partners of infertile couples. Circulating unbound antibody measured by tray agglutination test in serum and seminal plasma in a representative proportion.

SETTING

Seminology laboratory.

PATIENTS

One hundred nine male partners of infertile couples.

RESULTS

Highly significant correlation between direct MAR (IgG) and direct immunobed test (IgG) and between both of these tests and serum unbound antibody measured by tray agglutination test. Highly significant correlation between direct immunobead test (IgA) and seminal plasma unbound antibody measured by tray agglutination test, but no correlation with MAR (IgG).

CONCLUSIONS

Mixed antiglobulin reaction (IgG) is a cheap, quick, and sensitive screening test, but immunobead test (IgA) provides useful additional information on class of antibody on spermatozoa that may be clinically more important.

Comparison of the direct radiolabeled antiglobulin assay and the direct immunobead binding test for detection of sperm-associated antibodies

Thirty-seven semen samples were assayed for sperm-associated IgG and IgA using the immunobead test. Portions of these sperm samples were sent for testing with a direct radiolabeled antiglobulin assay and the testing results were compared. If the results of the immunobead test when only tail-tip bead binding was noted are regarded as negative, there was close correlation between the two assay methodologies.