Antisperm antibodies in cryptorchid boys

Immune infertility in men

Male factors are implicated as the cause of roughly half of cases of infertility, and the presence of antisperm antibodies (ASA) may be responsible for some of these. Their presence is associated with a reduction in natural conception and live birth and impacts the success of assisted reproductive technologies. Interpretation of the data regarding ASAs and fertility is complicated by a lack of standardization in testing methodology and test thresholds and a lack of data on their prevalence in the healthy fertile population. Although their pathogenesis remains elusive, and many cases are idiopathic, a disruption in the immunologic blood-testis barrier (BTB) appears to contribute to the formation of ASA. As delineation of the specific antigen targets of ASA advances, it has been recognized that they may affect almost all aspects of sperm function, and ASA against different targets likely have specific mechanisms of impairing fertility. Intracytoplasmic sperm injection (ICSI) appears to be the most reliable method by which to overcome fertility impairment due to ASA, achieving similar outcomes to ASA-negative patients with regard to fertilization rates, embryonic development, clinical pregnancy rates, and live birth rates. The lack of consistency in testing for and reporting ASA remains a substantial barrier to achieving clarity in describing their role in infertility and the optimal management approach, and future research should use a unified approach to the detection and description of ASA. Determination of the specific antigens targeted by ASA, and their function and clinical relevance, would contribute to improving the understanding of ASA-mediated impacts on fertility and tailoring treatment appropriately to achieve the best outcomes for patients.

Latheef S, Sharun K, Khurana SK, K. A, Tiwari R, Bhatt P, K. V, Chaicumpa W. Role of Antisperm Antibodies in Infertility, Pregnancy, and Potential forContraceptive and Antifertility Vaccine Designs: Research Progress and Pioneering Vision

Sperm of humans, non-human primates, and other mammalian subjects is considered to be antigenic. The effect of changes in autoimmunity on reproductive cells such as spermatozoa and oocytes play a critical but indistinct role in fertility. Antisperm antibodies (ASAs) are invariably present in both females and males. However, the degree of ASA occurrence may vary according to individual and gender. Although the extent of infertility due to ASAs alone is yet to be determined, it has been found in almost 9-12% of patients who are infertile due to different causes. Postcoital presence of spermatozoa in the reproductive tract of women is not a contributory factor in ASA generation. However, ASA generation may be induced by trauma to the vaginal mucosa, or by anal or oral sex resulting in the deposition of sperm inside the digestive tract. It is strongly believed that, in humans and other species, at least some antibodies may bind to sperm antigens, causing infertility. This form of infertility is termed as immunological infertility, which may be accompanied by impairment of fertility, even in individuals with normozoospermia. Researchers target ASAs for two major reasons: (i) to elucidate the association between ASAs and infertility, the reason ASAs causes infertility, and the mechanism underlying ASA-mediated infertility; and (ii) to assess the potential of ASAs as a contraceptive in humans in case ASAs influences infertility. Therefore, this review explores the potential application of ASAs in the development of anti-spermatozoa vaccines for contraceptive purposes. The usefulness of ASAs for diagnosing obstructive azoospermia, salpingitis, and oligoasthenoteratozoospermia has been reviewed extensively. Important patents pertaining to potential candidates for spermatozoa-derived vaccines that may be utilized as contraceptives are discussed in depth. Antifertility vaccines, as well as treatments for ASA-related infertility, are also highlighted. This review will address many unresolved issues regarding mechanisms involving ASAs in the diagnosis, as well as prognoses, of male infertility. More documented scientific reports are cited to support the mechanisms underlying the potential role of ASA in infertility. The usefulness of sperm antigens or ASAs (recombinant) in human and wild or captive animal contraceptive vaccines has been revealed through research but is yet to be validated via clinical testing.

Oxidative, inflammatory and immunologic status in children with undescended testes

BACKGROUND

In order to better understand the pathogenesis of risk of future sub-/infertility in children with undescended testes (UDT), we designed this prospective study to examine the oxidative stress, inflammatory response and autoimmunity in children with UDT. We examined the concentrations of malondialdehyde (MDA), interleukin-6 (IL-6) and antisperm antibodies (ASA) in children with UDT and healthy controls.

METHODS

The UDT group consisted of 88 boys (aged 1-14 years, unilateral in 67 and bilateral in 21 cases), and 44 boys with normal descended testes served as a control group. Clinical evaluation revealed no testicular or other system abnormalities. MDA was used as lipid peroxidation index. IL-6 levels were measured using a commercial enzyme-linked immunosorbent assay kit. ASA was determined with an anti-human spermatozoa immunoglobulin G test.

RESULTS

Mean age values ± SD were 4.6 ± 3.2 in the UDT group and 4.7 ± 3.4 in the control group (P= 0.872). MDA and IL-6 results for the UDT and control groups were significantly different (P= 0.003 and P= 0.019, respectively), but those for ASA were not (P= 0.473). The mean MDA and IL-6 values were significantly higher in bilateral cases than the respective values in the unilateral cases (MDA: 4.03 ± 3.68 vs 3.49 ± 5.22, P= 0.015; IL-6: 7.70 ± 6.86 vs 3.48 ± 6.50, P= 0.001) (P= 0.015).

CONCLUSION

The results indicate that children with UDT are exposed to high levels of oxidative stress and inflammatory reaction. This could negatively affect the future fertility in these children.

Weak association of anti-sperm antibodies and strong association of familial cryptorchidism/infertility with HLA-DRB1 polymorphisms in prepubertal Ukrainian boys

BACKGROUND

Cryptorchidism is a frequent syndrome occurring in 1-2% of males within the first year of age. Autoimmune reactions, particularly directed to testicular elements and/or spermatozoa have been found to be often associated with cryptorchidism. Therefore we investigated in this study the frequency of HLA class II alleles in order to recognize possible genetic predisposition for antisperm antibodies development in prepubertal boys with diagnosed cryptorchidism in Caucasoid population.

METHODS

Sixty prepubertal boys with cryptorchidism and sixty healthy boys were examined for anti-sperm antibodies by indirect immunobead test as well as for their HLA-DRB1 and -DQB1 alleles using DNA obtained from peripheral blood leukocytes. The typing of HLA-DRB1 and -DQB1 was performed by using PCR-SSP low resolution method.

RESULTS

Allele frequencies of HLA-DRB1 and HLA-DQB1 did not differ between boys with cryptorchidism and control boys. However, weakly significant differences in DRB1*04 (p corrected=0.0475) and DQB1*06 (p corrected=0.0385) were seen between cryptorchid patients with and without AsA, but none of these two patient groups differed significantly in HLA class II frequencies from controls except for AsA-negatives and HLA-DQB1*06 (p corrected=0.0247). On the other hand, comparison of cryptorchid boys with familial cryptorchidism and/or infertility to control boys revealed highly significant (p corrected=0.0006) difference in HLA-DRB*11 frequency, whereas boys with sporadic cryptorchidism did not differ from control. A much weaker, but still significant difference in DRB*11 frequency was also observed between boys with bilateral cryptorchidism and controls (p corrected=0.037), whereas patients with unilateral cryptorchidism were not different from control in frequency of any HLA-DRB1 or -DQB1 allele tested.

CONCLUSIONS

Predisposition to produce anti-sperm antibodies seems to be only weakly associated with HLA class II genes, although this question requires further study on much larger population sample. It is plausible that familial and sporadic cryptorchidism may present distinct genetic background. The same may, to lower extent, apply to bilateral and unilateral cryptorchidism.

ANTISPERM ANTIBODIES IN PREPUBERTAL BOYS WITH CRYPTORCHIDISM

The presence of antisperm antibodies in male individuals before puberty is controversial due to the lack of finally differentiated male germ cells. It was questioned whether the pathologic conditions of the male gonad may influence antisperm antibody formation in individuals before puberty. Sera samples of 76 individuals and 10 healthy boys with testicular failure (mainly uni- or bilateral cryptorchidism) were examined by means of indirect immunobead-binding test (IDIBT). The presence of antisperm antibodies was found in 3.95% of the studied subjects. Antibodies recognizing antigenic determinants present on the surface of mature sperm cells may be produced before puberty in individuals suffering from cryptorchidism or the other gonadal disorders. Antisperm antibodies that did develop in a minority of the studied male population may be proof for individual predispositions to autoimmune reactions.

Application of proteomic methods for identification of sperm immunogenic antigens

Although the immunogenic properties of sperm have been explored for a few decades, none of the antigens studied so far appears to be an effective target, to inhibit the fertilization process or shown the full spectrum of sperm antigenic potential. Antisperm antibodies (ASA) collected from infertile individuals and prepubertal boys with cryptorchidism together with two-dimensional (2D) electrophoresis have been employed. Immunoreactive antigens were cored from silver stained 2D gels and analyzed by mass spectrometry (MS). The obtained sequences were searched in the published protein databases. Altogether, 35 different sperm entities were identified in accessible protein databases, out of which 10 appeared to be sperm-specific. Additionally, 6 amino acid sequences indicated novel (hypothetical) proteins. Seventeen sperm entities were detected in sera samples from immune infertile males and 18 entities in ASA-positive seminal plasma (SP). Interestingly, we identified a few sperm structures, none of them sperm specific in sera samples from infertile females. Although, infertile males from whom the ASA-positive SP samples were obtained, did not have ASA in their circulation, the range of sperm antigens detected by systematic and local antibodies overlapped to a great extent (six identical entities). Sera samples from prepubertal boys allowed to show antigens, previously thought to be only present on mature sperm. Three out of four detected were sperm-specific. Using serum and SP of ASA-positive infertile adults and sera samples of prepubertal boys with testicular failure, we have extended the range of known, immunogenic sperm proteins as well as identified some novel antigens (n=6) of human sperm for further characterization.

TESTICULAR MICROLITHIASIS AND ANTISPERM ANTIBODIES FOLLOWING TESTICULAR BIOPSY IN BOYS WITH CRYPTORCHIDISM

PURPOSE

Testicular biopsy (TBx) performed during orchiopexy in boys with cryptorchidism can help to predict future semen analyses and possibly identify patients at risk for testicular cancer. It has been theorized that TBx can be detrimental to the long-term health of the testis. We examined testicular microlithiasis (TM) and antisperm antibody (ASA) production in cryptorchid TBx.

MATERIALS AND METHODS

A total of 112 males underwent fertility evaluation. These patients had previously undergone orchiopexy and bilateral TBx (mean age 8.6 years) for unilateral or bilateral undescended testis. At a mean age of 19.6 years all patients underwent physical examination and scrotal ultrasound for evaluation of testis size, echotexture and abnormalities. Of 112 patients 57 also underwent direct Immunobead(R) assay with positive controls. Moving sperm free and/or bound to IgG bead complex were counted in the preparation.

RESULTS

A total of 29 patients had bilateral and 83 had unilateral undescended testis. Of the 112 patients 26 were black and 86 were white. Four black patients (15.4%) and 4 white patients (4.7%) had testicular microlithiasis. Three patients had bilateral and 5 had unilateral diffuse TM. No tunica albuginea scars or testis masses were noted. In the 57 patients who underwent direct Immunobead assay no semen sample demonstrated evidence of forming bead-sperm complex, ie none had direct ASA.

CONCLUSIONS

No patient exhibited evidence of direct ASA. Prepubertal open TBx does not increase the rate of TM. We found no evidence of additive testicular damage associated with TBx at the time of orchiopexy.

Serum procalcitonin in pneumococcal pneumonia in children

Serum procalcitonin (PCT), a marker of bacterial infection, was measured in children with pneumonia to examine whether PCT can be used to screen pneumococcal (PNC) from viral pneumonia. The number of patients was 132; mean age 3.0 yrs, and 64% were males. In all cases, pneumonia was radiologically confirmed, being alveolar in 46 and interstitial in 86 cases. The aetiology of infection was studied by a panel of serological tests for PNC, for five other respiratory bacteria and for seven common respiratory viruses. PNC infection was found in 25, mixed viral-PNC infections in 13 and viral infection in 17 cases. In general, serum PCT was not associated with the type or aetiology of pneumonia. PCT values were >1.0 mg.L(-1) in 40% of PNC cases, as compared to 12-15% in viral or mixed cases, respectively (p<0.05). PCT values were significantly higher in >2 yrs old children than in younger ones. The cut-off limits of 0.5 ng.mL(-1), 1.0 ng.mL(-1) and 2.0 ng.mL(-1) were tested for screening between PNC and viral pneumonia. The highest sensitivity of 55% was found at the 0.5 ng.mL(-1) cut-off level, whereas the highest specificity of 88% was reached at the level of 1.0 ng.mL(-1). The likelihood ratios, however, were far from optimal for both the positive and negative results. Although marginally higher in pneumococcal pneumonia than in viral pneumonia, serum procalcitonin cannot be used to discriminate between these two types of pneumonia.

Absence of antisperm surface antibodies in prepubertal boys with cryptorchidism and other anomalies of the inguinoscrotal region before and after surgery

PURPOSE

Although the prepubertal immune system cannot recognize postmeiotic germ cell antigens, an overall 21 to 28% incidence of antisperm antibodies directed at these antigens has been reported preoperatively in prepubertal children with cryptorchidism and other inguinoscrotal anomalies. We investigated the prevalence of antisperm antibodies in these prepubertal patients before and after surgery.

MATERIALS AND METHODS

We examined 82 prepubertal boys 0.6 to 13.2 years old, including 33 with unilateral cryptorchidism, 21 with inguinoscrotal anomalies and 28 who were normal. IgG, IgM and IgA antisperm antibodies were determined by the indirect Immunobead test. Serum testing was repeated 1 and 2 years postoperatively and annually for 2 more years in the normal children. Also sera from 183 infertile men 21 to 47 years old with a history of cryptorchidism and/or inguinal hernia operated on in childhood were similarly studied.

RESULTS

Of the adults 70 (39%) tested IgG positive, including 12 (7%) who were also IgA positive, and all tested IgM negative. Repeat measurements were negative for all IgG, IgA and IgM isotypes in all children, patients and controls.

CONCLUSIONS

We conclude that there are no antibodies to sperm surface antigens in prepubertal children with cryptorchidism and inguinoscrotal anomalies before and within 2 years after surgery. Autoimmunity against postmeiotic sperm membrane antigens is apparent in adults only.