Antisperm antibodies in repeat‐breeding cows: Frequency, detection and validation of threshold levels employing sperm immobilization, sperm agglutination and immunoperoxidase assay

Abstract

Antisperm antibodies have been found in repeat-breeding(RB) cows, and those causing agglutination and/or immobilization of sperm are considered to be closely related to unexplained infertility. However, a standard protocol for identifying antisperm antibodies (ASA) in cattle is not validated. Therefore, an investigation was undertaken to evaluate sperm immobilization (SIT), sperm agglutination (SAT) and immunoperoxidase (IPT)assays for detection of ASA in serum and their respective threshold levels for confirmation. Animals (heifers, normally breeding, repeat-breeding and pregnant animals) that were free from IBR, brucellosis and uterine infections (screened by clinical examination) were included in the study. Sperm agglutinating, sperm immobilizing and antisperm antibodies evaluated by respective assay were significantly higher (p < .05) in RB cows compared to other groups. The SIT assay was able to identify 61% of RB caused by ASA, more than those employing SAT and IPT. Furthermore, a dilution rate of 1:5 and 1:80 (confirms 59.0 and 57.0% RB+ve)were sufficient to diagnose ASA by SAT and IPT, respectively. Results indicate the presence of __12.6% clumped spermatozoa and __ 2.6%(cut-off value) peroxidase-positive spermatozoa at 1:5 and 1:80 dilutions diagnosed with SAT and IPT, respectively, may be considered as repeaters arising out of ASA. Furthermore, study also showed the presence of lower incidence of ASA positivity in other groups of animals (heifer<normal breeder<pregnant animals) compared to repeaters. Study results show that although IPT is more specific and accurate but SAT and SIT are comparatively simple and cost-effective assays suitable for detecting ASA under field conditions and thus can be recommended for screening of repeaters.

Detection of sperm-reactive antibodies in wild sika deer and identification of the sperm antigens

“…Research in cattle, which is a relatively close species to deer, demonstrated that the incidences were much higher. Five point eight eight % of heifers, 25.00% of normal breeders, 18.75% of pregnant cows and 59.00% of repeat-breeders were positive in the sperm agglutination test [ 23 ]. Although we did not distinguish the gender and reproductive potential of individual deer, the prevalence was lower than that of fertile humans and domestic animals.…”

“…Antisperm antibodies occasionally emerge without such an active immunization. Repeat-breeding cows are frequently exposed to sperm antigens and produce sperm-reactive antibodies [ 23 ]. Some of the antibodies agglutinate and/or immobilize bull sperm, presumably reducing their fecundities.…”

Immune regulatory molecules as modifiers of semen and fertility: A review

“…To set the threshold levels for confirmation of the presence of ASAs in the serum of repeat breeding cows, various assays including the sperm immobilization test, sperm agglutination test, and immunoperoxidase test were carried out (Srivastava et al, ). The study reported the incidence of ASA positivity in female animals in this order: heifer < normal breeder < pregnant animals < repeaters and concluded that the immunoperoxidase test was more specific and accurate in detecting ASA in sera of the animals.…”

“…Though such antigens were not reported in livestock, ASA bound spermatozoa negatively affects the ability of spermatozoa to undergo capacitation and zona binding in bovine (Ferrer et al, ). Immobilization and sperm agglutination were observed in the cervical mucus of repeat breeding cows suffering from idiopathic infertility (Srivastava et al, ). The uterus is primarily an immune‐privileged site during pregnancy, yet reacts differently to various antigens during different phases of the reproductive cycle (Arck, Solano, Walecki, & Meinhardt, ; Clark & Schust, ).…”

Implications of cryopreservation on structural and functional attributes of bovine spermatozoa: An overview

“…In contrast, most antigenic proteins have been documented to have adverse effects on sperm function by generating anti‐sperm antibodies (ASAs) (IgG and IgA) in reproductive tract secretions, the possible cause of immune infertility in males (Archana et al., 2020). The difference in the effect of antigenicity between the functional attributes of fresh and frozen‐thawed spermatozoa could be due to degradation (Meggiolaro et al., 2003) or changes in the antigenic properties of proteins during cryopreservation (Lessard et al., 2000), or due to binding of secretory antibodies to surface antigens causing spermatozoa agglutination (Barbonetti et al., 2019; Srivastava et al., 2017). The ASAs block the sperm capacitation and zona binding by inhibiting the fluidity of the functional membrane (Ferrer et al., 2017) and tyrosine phosphorylation (Pujianto et al., 2018).…”