Induction of immunoresponse by subclinical male genital tract infection?**Presented in part at the 11th International Meeting of the European Society of Human Reproduction and Embryology, Hamburg, Germany, June 28 to July 1, 1995

Immunology of the Testis and Male Reproductive Tract

A large body of evidence points to the existence of a close, dynamic relationship between the immune system and the male reproductive tract, which has important implications for our understanding of both systems. The testis and the male reproductive tract provide an environment that protects the otherwise highly immunogenic spermatogenic cells and sperm from immunological attack. At the same time, secretions of the testis, including androgens, influence the development and mature functions of the immune system. Activation of the immune system has negative effects on both androgen and sperm production, so that systemic or local infection and inflammation compromise male fertility. The mechanisms underlying these interactions have begun to receive the attention from reproductive biologists and immunologists that they deserve, but many crucial details remain to be uncovered. A complete picture of male reproductive tract function and its response to toxic agents is contingent upon continued exploration of these interactions and the mechanisms involved.

Role for tumor necrosis factor alpha (TNF-alpha) and interleukin 1-beta (IL-1beta) determination in seminal plasma during infertility investigation

OBJECTIVE

To evaluate the clinical relevance of tumor necrosis factor alpha (TNF-alpha) and interleukin 1-beta (IL-1beta) determination in seminal plasma during infertility investigation.

DESIGN

Prospective study.

SETTING

Outpatient infertility clinic of a university-based hospital.

PATIENT(S)

Randomly chosen asymptomatic males (n = 148) from subfertile couples.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Determination of TNF-alpha and IL-1beta in seminal plasma (SP) by enzyme-linked immunosorbent assay (ELISA). In aliquots of the same ejaculates: 1) evaluation of semen quality with sperm analysis and sperm function testing; 2) determination of antisperm antibodies (ASA) of the immunoglobulin (Ig) G and IgA class; 3) microbial screening; and 4) immunocytochemical round cell differentiation to determine leukocyte counts and ratios. Medical history, clinical examination, and determination of subsequent fertility (after control for female infertility factors).

RESULT(S)

The concentrations of TNF-alpha and IL-1beta in SP correlated significantly (r = 0.65; P<.0001), and these parameters were significantly related to the leukocyte ratio (%LC) of the seminal round cells (r = 0.36; P<.001) and the leukocyte counts per ejaculate (r = 0.34; P<.001). There was no relationship of TNF-alpha and IL-1beta levels in SP with semen quality or parameters of sperm functional capacity, and there was no association with local ASA of the IgG or IgA class. The concentration of both cytokines was also not related to the outcome of the microbial screening and did not affect subsequent fertility. No correlation of TNF-alpha and IL-1beta levels in SP with the concentration of C-reactive protein in same-day serum samples was found.

CONCLUSION(S)

The levels of TNF-alpha and IL-1beta in seminal fluid correlate significantly with leukocyte counts and ratios in the same ejaculates, as indicators of silent male genital tract infection/inflammation. However, this is not related to semen cultures in asymptomatic individuals and not associated with clinically relevant parameters of semen quality, including sperm fertilizing capacity.

[Sperm biochemical markers of genital tract inflammation: usefulness of elastase determination]

Genital tract inflammation was for a long time suspected of inducing sterility in the male. The role of leukocytes in sperm changes is still debated. The identification of inflammation is based on the presence of activated leukocytes and the elastase measurement. Residual inflammation is evaluated by the reactive oxygen species activity. The true damage caused by inflammation on spermatozoa is reflected in negative changes observed during sperm apoptosis. Increased sperm DNA fragmentation is frequently observed while classical sperm characteristics are not modified automatically. The diagnosis of genital tract inflammation, follow-up after treatment and prognosis in terms of fertility require the use of different and complementary parameters.

Update on the impact of Chlamydia trachomatis infection on male fertility

With approximately 90 million cases annually, infection with Chlamydia trachomatis is the most prevalent sexually transmitted bacterial disease in the world. Considering that these infections are often asymptomatic and cause major complications like acute pelvic inflammatory disease, ectopic pregnancy, infertility or infant pneumonia, the estimated costs for diagnosis and treatment in the USA amounts to 2.2 million US dollars for each 500 cases. Therefore, there is a high need for correct, quick and cost-effective diagnosis and treatment of this urogenital tract infection. New innovative therapies provide good results with regard to efficacy and patients' compliance. The success rates of treatments are at least 95%. However, the occurrence of antibiotic resistance should not be ignored and new treatment schemes must be developed. The state-of-the-art of diagnosis and treatment of chlamydial infections as well as the pathophysiology is discussed in this review. In conclusion, infections with C. trachomatis is an important public health problem, especially in third world and developing countries, and more socio-economic studies linking secondary prevention of chlamydial infections, infertility and adverse pregnancy outcome are needed to understand more of its aetiology. In addition, diagnosis and treatment should be improved. Data in men revealed that past infections but not present infections are more related to male infertility. There is still controversial results. In future studies, function of the seminal vesicles and evaluation of the antioxidant capacity should be taken into account when role of C. trachomatis infection on male fertility is assessed.

Semen polymorphonuclear neutrophil leukocyte elastase as a diagnostic and prognostic marker of genital tract inflammation--a review

Elastase is a protease released by polymorphonuclear neutrophils (PMN) during the inflammatory process. Since 1987, seminal elastase-inhibitor complex (Ela/alpha1-PI) has been proposed as a marker of male silent genital tract inflammation. Measured by immunoassay in seminal plasma, Ela/alpha1-PI at a cut-off level of > or = 230 microg/l, is useful in the detection of genital tract inflammation. The prevalence of increased seminal Ela/alpha1-PI in infertile men is significantly higher than that observed in fertile men. The Ela/alpha1-PI level is positively correlated with other seminal fluid markers of male genital tract inflammation: reduced semen volume, citric acid, fructose, and increased albumin, complement component C3, caeruloplasmin, immunoglobulins IgG and IgA, and cytokines interleukins-8 and -6. A higher seminal Ela/alpha1-PI level is significantly associated with tubal damage in female partners. After antibiotic therapy, a decrease of Ela/alpha1-PI level is observed. The presence of tubal damage in the partner may negatively affect the response to antibiotic treatment. A higher seminal Ela/alpha1-PI is associated with lower percentage of sperm with single-stranded deoxyribonucleic acid (DNA) and better fertilization rate in in vitro fertilization. Besides infertility, the determination of Ela/alpha1-PI is useful to confirm the presence of prostate and other male accessory gland bacterial inflammation. Screening for PMN Ela/alpha1-PI is easy to perform and reproducible and is a reliable quantitative test for diagnosis and prognosis of silent genital tract inflammation of couples. Moreover, sequential determinations allow the follow-up of inflammation during and after therapy.

Seminal antibodies to human 60kd heat shock protein (HSP 60) in male partners of subfertile couples

BACKGROUND

Heat shock proteins (HSP) are essential mammalian and bacterial stress proteins. At the cellular level, they act as chaperones, have important regulatory functions, and are considered to be an essential factor for reproduction. Scarce information exists on the role of sensitization to HSP and the potential role in the aetiology of male infertility.

METHODS

The potential association of immunoglobulin (Ig)A antibodies (Ab) to the human 60 kDa heat shock protein (HSP 60) with several parameters of subclinical male genital tract infection/inflammation and with semen quality and sperm fertilizing capacity was analysed in a prospective study. IgA Ab to human HSP 60 were determined in seminal plasma of 202 randomly chosen male partners of subfertile couples with a median duration of infertility of 4 years (range 1-15 years), who were asymptomatic for genital tract infection. After medical history and clinical examination, a comprehensive evaluation of semen quality, in aliquots of the same ejaculates used for HSP Ab determination, included: sperm analysis; local antisperm antibody (ASA) screening; standardized sperm-cervical mucus (CM) penetration testing; immunocytochemical round cell differentiation to determine seminal leukocyte counts; evaluation of complement fraction C(3) and of some pro-inflammatory cytokines; and microbial screening. Subsequent fertility was recorded after 6 months.

RESULTS

The presence of HSP 60 IgA Ab in seminal fluid (total positive 6.9%) was significantly associated with leukocytospermia, the presence of C(3), and also with high interleukin (IL) levels in seminal plasma. HSP 60 Ab were not related to the bacterial colonization of ejaculates. There was no association of seminal IgA Ab to human HSP 60 with semen quality, determined with microscopical semen analysis, nor with local IgG- or IgA-class ASA. There was no relationship with sperm intrinsic motility and duration of motility in the sperm CM-penetration test, nor with sperm fertilizing capacity.

CONCLUSIONS

The combined presence of IgA Ab to human 60 kDa HSP, leukocytes and other established infection/inflammation markers in semen might suggest a potential role of the immune response to heat shock proteins (HSP) in cases of silent male genital tract infection, but the results do not indicate a marked relationship of HSP 60 Ab in seminal fluid with standard parameters of semen quality.

Relationship of seminal plasma interleukin (IL) -8 and IL-6 with semen quality

The concentration of interleukin (IL) -8 and IL-6 was determined in seminal plasma (SP) samples from 137 randomly chosen subfertile males to evaluate the relationship with other potential parameters of subclinical infection/inflammation such as seminal leukocytes, and with semen quality in a prospective study. All patients were asymptomatic for genital tract infection. A comprehensive semen evaluation included sperm analysis, sperm migration testing, antisperm antibody screening, immunocytochemical round cell differentiation to determine seminal leukocytes counts and the leukocyte ratio, complement fraction C(3) (C(3c)) determination, and semen cultures, in aliquots of the same ejaculates. The SP concentration of IL-8 was inversely related to semen quality, e.g. to the total number of motile spermatozoa or to the outcome of the sperm migration test (motile sperm harvested after a swim-up procedure). IL-8 concentrations were significantly correlated with leukocyte counts per ml (P < 0.0001) and per ejaculate (P < 0.0001), and with the leukocyte ratio (P < 0.001). All leukocytospermic samples had high IL-8 concentrations (< or =2 ng/ml). The SP concentration of IL-6 was much lower, but was significantly correlated with IL-8 (P < 0.0001). Both IL-8 and IL-6 were significantly related with the C(3c). No association of interleukin concentrations with the bacterial colonization of semen samples was found. The results indicate a marked relationship of some pro-inflammatory cytokines with semen quality. The significant association with seminal leukocytes and other potential inflammation markers suggests that IL-8 might be used as sensitive marker for silent male genital tract infection.

Semen granulocyte elastase: its relevance for the diagnosis and prognosis of silent genital tract inflammation

Elastase-inhibitor complex was assessed by immunoassay in the seminal plasma of 312 men attending the outpatient infertility clinic. Using receiver operating characteristic (ROC) curve analysis, elastase at the cut-off value of > or =290 ng/ml was shown to be efficient (sensitivity 79.5%, specificity 74.4%) in the detection of genital tract inflammation as defined by leukocytospermia (>1x10(6) leukocytes/ml). The prevalence of increased elastase in 292 infertile men was significantly higher (34%) as compared with that (5%) observed in 20 fertile men (P: = 0.02). Moreover, high elastase concentration (> or =290 ng/ml) was observed in 66 of the 264 men (25%) without leukocytospermia. A significant positive correlation was found between elastase concentration and patient age (r = 0.202, P: < 0.0001) and the number of leukocytes (r = 0.330, P: < 0.0001). A negative correlation was found between elastase concentration and semen volume (r = -0.146, P: = 0.01) and the percentage of spermatozoa with single-stranded DNA (r = -0.194, P: = 0.024), but there was no correlation between elastase and sperm reactive oxygen species production. A higher seminal elastase concentration was significantly associated with tubal damage in female partners (P: < 0.001). After norfloxacine antibiotic therapy, decrease in elastase concentration was observed in 15 (25%) of the 60 treated patients. Tubal damage in the partner negatively affected the response to antibiotic therapy. In conclusion, granulocyte elastase is a reliable screening test for silent genital tract inflammation of the couple. The elastase-inhibitor complex may have a protective effect in reducing sperm DNA denaturation.

Antisperm antibodies and microorganisms in genital secretions--a clinically significant relationship?

In asymptomatic infertility patients, no significant relationship was found between the presence of antisperm antibodies (ASA) in serum and in semen samples (IgG and/or IgA ASA), differentiated with the mixed antiglobulin reaction (MAR), and the microbial colonization of ejaculates covering a broad spectrum of microorganisms. Likewise, there was no significant association of ASA with microbial findings in patients' female partners, who also presented without symptoms of genital tract infection and were screened at the same time. Furthermore, ASA in semen (IgG and IgA) were not significantly related to several potential markers of subclinical male sexual gland infection or inflammation (leukocytes, PMN elastase, albumin, C3c) evaluated in aliquots of the same ejaculates used for immunological testing.