Testicular immune cell populations and macrophage polarisation in adult male mice and the influence of altered activin A levels

Detailed morphological characterization of testicular leukocytes in the adult CX₃CR₁^gfp/+ transgenic mouse identified two distinct CX₃CR₁⁺ mononuclear phagocyte (macrophage and dendritic cell) populations: stellate/dendriform cells opposed to the seminiferous tubules (peritubular), and polygonal cells associated with Leydig cells (interstitial). Using confocal microscopy combined with stereological enumeration of CX₃CR₁^gfp/+ cells established that there were twice as many interstitial cells (68%) as peritubular cells (32%). Flow cytometric analyses of interstitial cells from mechanically-dissociated testes identified multiple mononuclear phagocyte subsets based on surface marker expression (CX₃CR₁, F4/80, CD11c). These cells comprised 80% of total intratesticular leukocytes, as identified by CD45 expression. The remaining leukocytes were CD3⁺ (T lymphocytes) and NK1.1⁺ (natural killer cells). Functional phenotype assessment using CD206 (an anti-inflammatory/M2 marker) and MHC class II (an activation marker) identified a potentially tolerogenic CD206⁺MHCII⁺ sub-population (12% of total CD45⁺ cells). Rare testicular subsets of CX₃CR₁⁺CD11c⁺F4/80⁺ (4.3%) mononuclear phagocytes and CD3⁺NK1.1⁺ (3.1%) lymphocytes were also identified for the first time. In order to examine the potential for the immunoregulatory cytokine, activin A to modulate testicular immune cell populations, testes from adult mice with reduced activin A (Inhba^+/-) or elevated activin A (Inha^+/-) were assessed using flow cytometry. Although the proportion of F4/80⁺CD11b⁺ leukocytes (macrophages) was not affected, the frequency of CD206⁺MHCII⁺cells was significantly lower and CD206⁺MHCII^- correspondingly higher in Inha^+/- testes. This shift in expression of MHCII in CD206⁺ macrophages indicates that changes in circulating and/or local activin A influence resident macrophage activation and phenotype and, therefore, the immunological environment of the testis.

CCL20-CCR6 axis directs sperm-oocyte interaction and its dysregulation correlates/associates with male infertility‡

The interaction of sperm with the oocyte is pivotal during the process of mammalian fertilization. The limited numbers of sperm that reach the fallopian tube as well as anatomic restrictions indicate that human sperm-oocyte encounter is not a matter of chance but a directed process. Chemotaxis is the proposed mechanism for re-orientating sperm toward the source of a chemoattractant and hence to the oocyte. Chemokines represent a superfamily of small (8-11 kDa), cytokine-like proteins that have been shown to mediate chemotaxis and tissue-specific homing of leukocytes through binding to specific chemokine receptors such as CCRs. Here we show that CCR6 is abundantly expressed on human sperms and in human testes. Furthermore, radioligand-binding experiments showed that CCL20 bound human sperm in a specific manner. Conversely, granulosa cells of the oocyte-surrounding cumulus complex as well as human oocytes represent an abundant source of the CCR6-specific ligand CCL20. In human ovaries, CCL20 shows a cycle-dependent expression pattern with peak expression in the preovulatory phase and CCL20 protein induces chemotactic responses of human sperm. Neutralization of CCL20 in ovarian follicular fluid significantly impairs sperm migratory responses. Conversely, analyses in infertile men with inflammatory conditions of the reproductive organs demonstrate a significant increase of CCL20/CCR6 expression in testis and ejaculate. Taken together, findings of the present study suggest that CCR6-CCL20 interaction may represent an important factor in directing sperm-oocyte interaction.

[Orchitis]

Orchitis can be acutely symptomatic or chronically asymptomatic. Among the acute forms is the rarer isolated orchitis, which is of viral origin in most cases as well as the more frequent secondary orchitis, which is usually the result of an ascending bacterial epididymitis. In addition, sterile forms of orchitis are also seen in patients with systemic autoimmune comorbidities. Chronic asymptomatic orchitis is the term used to describe cellular immune infiltrates in the testes, which are observed in approximately 25% of cases of azoospermia during testicular biopsy. The etiopathogenesis of these infiltrates is largely unknown with postinfection and primary pathogen-independent autoimmune reactions being discussed. Animal experimental models of orchitis may be helpful to investigate the immunological mechanisms involved as well as the therapeutic possibilities.

Activin A target genes are differentially expressed between normal and neoplastic adult human testes: clues to gonocyte fate choice

BACKGROUND

Human testicular germ cell tumours (TGCT) arise from germ cell neoplasia in situ (GCNIS) cells that originate from foetal germ cell precursors. Activin A is central to normal foetal testis development, and its dysregulation may contribute to TGCT aetiology.

OBJECTIVE

(i) To test whether the expression profiles of activin A targets in normal and neoplastic human testes indicates functional links with TGCT progression. (ii) To investigate whether activin A levels influence MMP activity in a neoplastic germ cell line.

MATERIALS AND METHODS

(1) Bouin's fixed, paraffin-embedded human testes were utilized for PCR-based transcript analysis and immunohistochemistry. Samples (n = 5 per group) contained the following: (i) normal spermatogenesis, (ii) GCNIS or (iii) seminoma. CXCL12, CCL17, MMP2 and MMP9 were investigated. (2) The human seminoma-derived TCam-2 cell line was exposed to activin A (24 h), and target transcripts were measured by qRT-PCR (n = 4). ELISA (n = 4) and gelatin zymography (n = 3) showed changes in protein level and enzyme activity, respectively.

RESULTS

(i) Cytoplasmic CXCL12 was detected in Sertoli and other somatic cells, including those surrounding seminoma cells. Anti-CCL17 labelled only the cytoplasm of Sertoli cells surrounding GCNIS, while anti-MMP2 and anti-MMP9 labelled germline and epithelial-like cells in normal and neoplastic testes. (ii) Exposing TCam-2 cells to activin A (50 ng/mL) elevated MMP2 and MMP9 transcripts (fourfold and 30-fold), while only MMP2 protein levels were significantly higher after activin A (5 ng/mL and 50 ng/mL) exposure. Importantly, gelatin zymography revealed activin A increased production of activated MMP2.

DISCUSSION

Detection of CCL17 only in GCNIS tumours may reflect a change in Sertoli cell phenotype to a less mature state. Stimulation of MMP2 activity by activin A in TCam-2 cells suggests activin influences TGCT by modulating the tumour niche.

CONCLUSION

This knowledge provides a basis for understanding how physiological changes that influence activin/TGF-β superfamily signalling may alter germ cell fate.

An in vitro model demonstrates the potential of neoplastic human germ cells to influence the tumour microenvironment

Testicular germ cell tumours (TGCT) typically contain high numbers of infiltrating immune cells, yet the functional nature and consequences of interactions between GCNIS (germ cell neoplasia in situ) or seminoma cells and immune cells remain unknown. A co-culture model using the seminoma-derived TCam-2 cell line and peripheral blood mononuclear cells (PBMC, n = 7 healthy donors) was established to investigate how tumour and immune cells each contribute to the cytokine microenvironment associated with TGCT. Three different co-culture approaches were employed: direct contact during culture to simulate in situ cellular interactions occurring within seminomas (n = 9); indirect contact using well inserts to mimic GCNIS, in which a basement membrane separates the neoplastic germ cells and immune cells (n = 3); and PBMC stimulation prior to direct contact during culture to overcome the potential lack of immune cell activation (n = 3). Transcript levels for key cytokines in PBMC and TCam-2 cell fractions were determined using RT-qPCR. TCam-2 cell fractions showed an immediate increase (within 24 h) in several cytokine mRNAs after direct contact with PBMC, whereas immune cell fractions did not. The high levels of interleukin-6 (IL6) mRNA and protein associated with TCam-2 cells implicate this cytokine as important to seminoma physiology. Use of PBMCs from different donors revealed a robust, repeatable pattern of changes in TCam-2 and PBMC cytokine mRNAs, independent of potential inter-donor variation in immune cell responsiveness. This in vitro model recapitulated previous data from clinical TGCT biopsies, revealing similar cytokine expression profiles and indicating its suitability for exploring the in vivo circumstances of TGCT. Despite the limitations of using a cell line to mimic in vivo events, these results indicate how neoplastic germ cells can directly shape the surrounding tumour microenvironment, including by influencing local immune responses. IL6 production by seminoma cells may be a practical target for early diagnosis and/or treatment of TGCT.

[Dermatological diseases and sexuality. How to proceed?]

A variety of dermatological diseases is associated with male or female sexual dysfunction. Some sexual disorders are caused organically; erectile dysfunction in men with systemic sclerosis may be due to penile vascular alterations and corporal fibrosis. Other dermatoses such as psoriasis are associated with risk factors (metabolic syndrome) for sexual disorders and may therefore indirectly induce erectile dysfunction. However, the majority of sexual dysfunctions in dermatological patients is caused by reduced self confidence and sexual self esteem leading to affected partnership and sexuality. Dermatologists should be trained in basic sexual medicine and ask their patients for sexual problems. They may not treat sexual disorders, but they should be identified as sympathetic physicians for these problems and should be able to refer the patient to specialists in sexual medicine.

Experimental Escherichia coli epididymitis in rats: assessment of testicular involvement in a long-term follow-up

The objective of this study was to investigate spermatogenesis and testicular inflammation in a rat model of unilateral Escherichia coli epididymitis in a long-term follow-up. Unilateral epididymitis was induced in 30 Sprague-Dawley rats by injecting E. coli into the right ductus deferens. Oral antimicrobial treatment with sparfloxacin (50 mg kg(-1) body weight/7 days) was administered in half of the animals 24 h after infection. Five treated and five untreated rats were killed at 2 weeks, 3 months and 6 months after infection. Spermatogenesis was investigated using a histological semi-quantitative score. The presence of inflammatory cells (B- and T lymphocytes, macrophages and granulocytes) in the testicular tissues was evaluated by immunohistochemistry. The testes were sterile at all times. Over the course of 6 months, spermatogenesis underwent significant incremental impairment on the inoculated side as compared to the contralateral side (P < 0.001). However, overall spermatogenesis scores were not significantly different between treated and untreated animals (P > 0.3 at each time point). Finally, loss of testicular architecture on the inoculated side was not associated with any cellular inflammatory response. Thus, adjuvant therapies need to be studied, and research is necessary on how to prevent deterioration of testicular function in bacterial epididymitis.

Prostatitis and andrological implications

AIM

The prostatitis syndrome is a frequent disease affecting men in their reproductive age. The prostatitis syndrome is classified according to the National Institutes of Health (NIH) definition. Andrological implications of the prostatitis syndrome might encompass fertility issues, sexual dysfunctions and endocrinological alterations and influences.

METHODS

A medline query using the terms prostatitis AND andrological implication, fertility, sexual dysfunction or endocrinology was performed.

RESULTS

Acute bacterial prostatitis and andrological implications have not been adequately addressed. Patients with chronic bacterial prostatitis and chronic pelvic pain syndrome have been investigated evaluating sperm parameters. Some studies showed impaired sperm parameters. In chronic bacterial prostatitis, half of the patients reveal significant bacteriospermia with still debatable deleterious effects on sperm quality. Few interventional studies have addressed fertility issues in those patients. Anti-inflammatory treatment perhaps could have a positive impact on sperm parameters. Sexual dysfunction can be described by different components such as erectile, ejaculatory, orgasmic and sexual desire dysfunctions. Sexual dysfunction in chronic prostatitis adds to the number of positive symptom phenotypes and correlates therefore with increasing symptom scores in patients with chronic prostatitis syndromes. However, prospective interventional studies on the role of sexual dysfunctions are missing. Hormones have been found to modulate the inflammatory response via different receptors, particularly via estrogen receptor alpha. This evidence, however, is mainly limited to pre-clinical studies currently.

CONCLUSION

Andrological implications are heterogenous and frequently described in patients with chronic prostatitis syndrome. Nonetheless, andrological factors have not been routinely addressed as primary variables in the different studies, which makes further research necessary.

Presence of histone H3 acetylated at lysine 9 in male germ cells and its distribution pattern in the genome of human spermatozoa

During spermatogenesis, approximately 85% of histones are replaced by protamines. The remaining histones have been proposed to carry essential marks for the establishment of epigenetic information in the offspring. The aim of the present study was to analyse the expression pattern of histone H3 acetylated at lysine 9 (H3K9ac) during normal and impaired spermatogenesis and the binding pattern of H3K9ac to selected genes within ejaculates. Testicular biopsies, as well as semen samples, were used for immunohistochemistry. Chromatin immunoprecipitation was performed with ejaculated sperm chromatin. HeLa cells and prostate tissue served as controls. Binding of selected genes was evaluated by semiquantitative and real-time polymerase chain reaction. Immunohistochemistry of H3K9ac demonstrated positive signals in spermatogonia, spermatocytes, elongating spermatids and ejaculated spermatozoa of fertile and infertile men. H3K9ac was associated with gene promoters (CRAT, G6PD, MCF2L), exons (SOX2, GAPDH, STK11IP, FLNA, PLXNA3, SH3GLB2, CTSD) and intergenic regions (TH) in fertile men and revealed shifts of the distribution pattern in ejaculated spermatozoa of infertile men. In conclusion, H3K9ac is present in male germ cells and may play a role during the development of human spermatozoa. In addition, H3K9ac is associated with specific regions of the sperm genome defining an epigenetic code that may influence gene expression directly after fertilisation.

[News from andrology. Infertility, erectile dysfunction, and hypogonadism]

This contribution discusses new aspects in andrology focusing on infertility, erectile dysfunction (ED), and hypogonadism. Topics such as prostatitis and detection of Chlamydia, idiopathic infertility and PDE5 inhibitors, and ED after GreenLight laser treatment are addressed.

Validation of reference genes in human testis and ejaculate

Beta-actin (ACTB), glyceraldehyde-3-phosphate-dehydrogenase (GAPD), Heat Shock Protein 1, beta (HSPCB) and Adenosine Triphosphate subunit 5 beta (ATP5B) with distinct functional characteristics and expression patterns were investigated as suitable references for gene expression studies. We determined the expression stability of the four reference genes in ejaculates, cryopreserved as well as fixed and paraffin-embedded testicular tissue (from fertile and subfertile men) applying real-time qRT-PCR and statistical analysis. The mean gene expressions (mean Ct value) were compared for each gene between the fertile and subfertile donors by using the Wilcoxon-Mann-Whitney test. We did not observe significant statistical differences between variability of genes. To detect random effects, we used the two-way analysis of variance with a hierarchical model. The results show no significant statistical differences between proband and repetition within the probands. Taken together, we concluded that ACTB, GAPD, HSPCB and ATP5B have a variable expression within these samples, but this variability is not statistically significant. This finding demonstrated that all these genes could be appropriated for further studies on gene expression in ejaculate and testis tissue. Therefore, the selection of the suitable reference genes is highly specific for a particular experimental model and validation for each situation, on an individual basis, is a crucial requirement.

[Orchitis and male infertility]

Infections and inflammations of the genital tract are considered the most frequent causes of reduced male fertility, but conclusive epidemiological data are not available. In view of the exposure of germ cells to pathogenic components as well as the cells and mediators involved in the inflammatory processes, irreversible damage to spermatogenesis and corresponding decline of ejaculate quality are to be expected, particularly in cases of chronic orchitis. While the consequences of orchitis and epididymo-orchitis that exhibit clinical symptoms due to systemic or local infections are well known, including testicular atrophy and complete loss of fertility, those cases of inflammatory reactions of the testicles that manifest an asymptomatic or subclinical course, or are not even due to an infection, have received little attention until now. However, systematic histopathological analyses have shown a high prevalence of asymptomatic inflammatory reactions in testicular biopsies from infertile men. The mostly focal lymphocytic infiltrates correlate with the degree of damage to spermatogenesis and corresponding clinical and endocrinological parameters of testicular function. Noninvasive diagnostic techniques are not yet available so that chronic asymptomatic inflammations of the testicles as the primary cause or cofactor of male fertility disorders are underestimated. Except for administration of pathogen-specific antibiotics, treatment recommendations are to a large extent still lacking.

Expression and putative function of lymphocyte endothelial epithelial-cell adhesion molecule in human testis

The testis is an immunologically privileged site where germ cell antigens are protected from autoimmune attack and foreign tissue grafts may survive for extended periods. However, the testicular environment does not preclude inflammatory reactions and tissue-specific recruitment of T lymphocytes appears to be a crucial component of the inflammation cascade. Here, we demonstrate expression of lymphocyte endothelial epithelial-cell adhesion molecule (LEEP-CAM), a putative receptor mediating lymphocyte adhesion to endothelia and some epithelia, in human testis. In all specimens examined, expression of LEEP-CAM could be observed on endothelial cells of testicular blood vessels, including those within the lamina propria of seminiferous tubules. Sections of histologically normal testis showed strong LEEP-CAM expression within the seminiferous epithelium localised to Sertoli cells, whereas immunoreactivity was almost absent in tubules with severely impaired spermatogenesis. In a modified Stamper-Woodruff adhesion assay, binding of activated lymphocytes to normal testicular tissue was reduced by 61% after incubation with anti-LEEP-CAM mAb as compared with controls (P < 0.00001). In conclusion, intratubular LEEP-CAM expression is correlated with normal spermatogenesis and Sertoli cell function. In this context, it may contribute to adhesive cell-cell interactions. Moreover, the constitutive expression in human testis could play a role for localisation of T cells during testicular inflammation.

Influence of moderate cycling on scrotal temperature

Testicular temperature highly correlates with scrotal temperature. It has been postulated that cycling is associated with increased scrotal temperatures with time and consecutively with impaired semen quality. The aim of this study was to evaluate the influence of moderate cycling on scrotal temperature during highly standardized conditions in an experimental lab. A total of 25 volunteers without a history of infertility and normal andrological examination were included for scrotal temperature evaluation. Scrotal temperatures were measured every minute with a portable data recorder connected with two thermistor temperature sensors, which were attached on either side of the scrotum. A further thermistor sensor was attached on the central surface of the bicycle saddle. Ambient temperature in the study room was adjusted to 22 degrees C throughout the whole experiment. All volunteers started the experiment at the same daytime. Clothing of the volunteers consisted of standardized cotton wool trousers and shirts fitting to body size. After acclimatization to the study room in a sitting posture, each volunteer cycled on an exercise cycle for 60 min with a power of 25 Watt representing a speed of 25.45 km/h respectively. The saddle surface temperature reached in the median 35.59 degrees C after 60 min cycling. Median values of scrotal temperatures increased from 35.75 degrees C at the beginning to 35.82 degrees C after 60 min for the left side and from 35.50 to 35.59 degrees C for the right side. No correlation between cycling duration and scrotal temperatures could be found using multivariate anova for repeated measurements. However, scrotal temperatures during cycling were significantly lower (p < 0.001) compared with the last 10 min in sitting posture before starting cycling with a difference of 1.31 degrees C for the left and 1.46 degrees C for the right side. The present study suggests that moderate cycling under standardized conditions with a power of 25 Watt is not a major genital heat stress factor.

Influence of motility and vitality in intracytoplasmic sperm injection with ejaculated and testicular sperm

The vitality of spermatozoa used for intracytoplasmic sperm injection (ICSI) is a crucial factor for fertilization, establishment and outcome of a pregnancy in assisted reproductive technique cycles. The sperm origin may also be a limiting factor, although little is known about this issue. It is known that the motility of injected spermatozoa and their origin from ejaculate or testicular biopsies are important predictors in terms of fertilization, pregnancy and birth rates. Oocytes of patients in 2593 cycles were retrieved in our in vitro fertilization programme and inseminated via ICSI. We used motile (group 1, n = 2317) or immotile ejaculated spermatozoa (group 2, n = 79), motile sperm retrieved from testicular biopsies (group 3, n = 62) and immotile spermatozoa from testicular biopsies (group 4, n = 135). Female age and number of oocytes retrieved did not differ significantly among the groups. The fertilization rates were as follows: 67.1% in group 1, 49.8% in group 2, 68.3% in group 3 and 47.8% in group 4. The pregnancy rates in cases where three embryos had been transferred amounted to 35.7% in group 1, 17.3% in group 2, 38.3% in group 3 and 20.5% in group 4. The embryo quality showed no differences between groups 1 and 3 (14.5), and between groups 2 (11.8) and 4 (10.8). The abortion rate was similar in groups 1-3, but increased in group 4 (26.6%, 27.3%, 31.6% and 55.5%). Irrespective of their origin, the fertilization potential of injected spermatozoa was found to be influenced by motility. The resulting pregnancy and birth rates, i.e. the potential of the resulting embryos to implant and to achieve viable pregnancies, seem to be additionally dependent on the sperm origin. This was well shown by declining rates when spermatozoa in a relatively early stage of maturity had been used. We see increasing evidence that the degree of sperm maturity has an important impact on the outcome of ICSI. In obstructive azoospermia, spermatozoa retrieved from the epididymis should be used rather than testicular biopsy spermatozoa, or testicular sperm should be preincubated in culture medium before ICSI.

Improvement of semen quality by nocturnal scrotal cooling in oligozoospermic men with a history of testicular maldescent

For infertile men with a history of testicular maldescent only few therapeutic options exist beside assisted reproduction. The aim of our study was to evaluate the influence of nocturnal scrotal cooling on semen quality in such patients presenting with oligozoospermia. Twenty infertile men with a history of testicular maldescent and oligozoospermia were included for nocturnal scrotal cooling over 12 weeks for every night. To increase nocturnal periscrotal air circulation we used a membrane pump connected via plastic tubes to receptacles placed in both groins. Semen analysis was performed at the beginning of the cooling period and at weeks 4, 8 and 12. Another 20 infertile patients with a history of testicular maldescent and oligozoospermia were followed without specific treatment and served as a retrospectively built control group. Scrotal cooling at night by means of a perigenital air stream resulted in a scrotal temperature drop by 0.8 degrees C (median). A significant increase in sperm concentration and total sperm count was achieved by nocturnal cooling after 8 weeks (p < 0.01; p < 0.05; respectively) and 12 weeks (p < 0.01; p < 0.01; respectively). The improvement of sperm motility and sperm morphology was statistically insignificant. The present study suggests nocturnal scrotal cooling as a therapeutic option to improve semen quality. In a further controlled prospective study the influence on pregnancy rates should be evaluated.

Influence of the type of undertrousers and physical activity on scrotal temperature

BACKGROUND

Testicular temperature correlates highly with scrotal temperature. The aim of this study was to evaluate the influence of the type of undertrousers on scrotal temperature during standardized periods of sitting and walking.

METHODS

Fifty volunteers without a history of infertility and normal andrological examination were included for scrotal temperature evaluation. Temperatures were measured every minute with a portable data recorder connected with two thermistor temperature sensors, which were attached on either side of the scrotum. Ambient temperature in the study room was adjusted to 20 degrees C throughout the whole experiment. All volunteers started the experiment at the same time of day. Clothing of the volunteers consisted of standardized cotton wool trousers and shirts fitting to body size. Each volunteer performed six periods of 45 min, either walking on a treadmill (3.0 km/h) or sitting, and wearing in a standardized and randomized manner either tight, loose fitting or no undertrousers respectively.

RESULTS

The following interactions were demonstrated by means of multivariate analysis of variance for repeated measurements: scrotal temperatures were significantly higher for tight versus loose fitting versus absent undertrousers. Furthermore, significantly lower scrotal temperatures were identified for walking versus sitting as well as for the right versus the left scrotal side.

CONCLUSIONS

The present study suggests that wearing tight fitting undertrousers is associated with higher scrotal and consequently testicular temperatures than wearing loose fitting undertrousers or none.

The male reproductive system and its susceptibility to endocrine disrupting chemicals

In the past years, there has been increased interest in assessing the relationship between impaired male fertility and environmental factors. Human male fertility is a complex process and therefore a great variety of sites may be affected by exogenous noxae. Lifestyle factors as well as various environmental and occupational agents may impair male fertility. Many studies have been published reporting on reproductive dysfunctions in male animals and humans. Especially environmental pollutants with endocrine activity are discussed as a possible cause of this detrimental development. Evidence from animal experiments show that substances with oestrogenic and antiandrogenic properties may cause hypospadia, cryptorchidism, reduction of sperm density and an increase of testicular tumours. Many adverse effects on animal male fertility have been documented for phthalates and some chlorinated hydrocarbons such as polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins. For other chemicals such as bisphenol A and nonylphenols animal data are conflicting. Environmental pollutants may mediate their effects by receptor binding, modulation of hormone-regulated mechanisms or direct toxic effects. Data on environmental chemicals and human male fertility are scarce, and risk assessment is mostly based on the results of animal studies. However, there are indications that exposure to endocrine active chemicals during early development may alter hormone responsiveness in adulthood. Furthermore, some of the chemicals are found in fluids that are associated with human reproduction, such as follicular fluid, seminal fluid and cervical mucus. Recent studies suggest a correlation between pesticide exposure and standard semen parameters as well as in vitro fertilization rates.

Anti-inflammatory and varicocele treatment in nonobstructive azoospermia

A 34-year-old male patient with nonobstructive azoospermia and childlessness for more than 2 years is presented. As even severely damaged testes often harbour cryptic areas with remaining spermatogenesis, such cases might be suitable for spermatid extraction from bilateral testicular biopsies. Taking into account that testicular biopsies bear the risk of permanent testosterone insufficiency, less invasive andrological treatment modalities were considered. Under the assumption of frequent silent testicular inflammatory reactions, the nonsteroidal anti-inflammatory drug ibuprofen was administered. Additionally, a concomitant left-sided varicocele was removed by retrograde sclerotherapy. Within 1 year, the spermiogram showed spermatozoa at a concentration of 0.6-1.2 million ml(-1). This allowed ejaculate samples to be stored for cryopreservation to enable in vitro fertilization with intracytoplasmic injection of spermatozoa. Our successfully performed anti-inflammatory and varicocele treatment underlines the value of conservative andrological therapies. Despite the modern possibilities of assisted reproductive procedures the clinical andrologist should be aware of a careful andrological examination and of less invasive therapeutic options such as anti-inflammatory treatment and varicocele repair.

Are children of older fathers at risk for genetic disorders?

Genetic risks related to paternal age should be of interest to clinical andrologists counselling older men who wish to father a child. Theoretically, the number of (pre-meiotic) mitotic cell divisions during spermatogenesis and their remarkable increase with ageing compared with oogenesis would be in favour of genetic risks for the offspring of older men. But for numerical and structural chromosomal anomalies, such an influence of paternal age has not been found. However, in several autosomal dominant disorders affecting three specific genes (fibroblast growth factor receptor 2 and 3, RET proto-oncogene) the risk for a child to be affected increases with paternal age at time of birth. For other autosomal dominant -X chromosomal dominant or recessive disorders, the available data are sufficient to support the concept of a positive relationship between paternal age and de novo gene mutations. Studies analysing gene sequences of affected children and their parents would allow further evaluation of this topic. The impact of paternal age on disorders with a complex genetic background, however, is a matter of debate. A significant effect of paternal age could not be shown for nonfamilial Alzheimer's disease, congenital heart defects, nonfamilial schizophrenia, acute lymphoblastic leukaemia or prostate cancer.

Genital heat stress in men of barren couples: a prospective evaluation by means of a questionnaire

Exposure to genital heat stress among men of barren couples was evaluated in a prospective study. Five hundred and forty-two consecutive patients referred for andrological examination were asked to complete a specific questionnaire at their first visit. For 449 patients who answered all questions, the individual score values could be calculated by scoring each answer with points. Patients with 'idiopathic' oligoasthenoteratozoospermia had significantly higher score values when compared with men showing normozoospermia (P < 0.01), 'symptomatic' oligoasthenoteratozoospermia as a result of defined andrological disorders (P < 0.01), cryptozoospermia (P < 0.01) or other pathological semen profiles (P < 0.05). These data support the hypothesis that patients with 'idiopathic' oligoasthenoteratozoospermia are more exposed to genital heat stress than normozoospermic men. Moreover, in patients with a varicocele impairment semen quality was associated with significantly higher score values compared with the subgroup of men with normal semen profiles (P < 0.05). In contrast, the score values did not significantly differ between equivalent subgroups of men with a history of a retractile testis. Our observations indicate that the questionnaire used in the present study allows an integrative assessment of genital heat stress, which is superior to single factor analysis. Notably, the group of men with 'idiopathic' oligoasthenoteratozoospermia showed the highest mean score values for 10 of the 18 questions compared with the other groups. Prolonged sitting in a vehicle represented the only single factor with significantly different score values in patients with 'idiopathic' oligoasthenoteratozoospermia and those with normozoospermia (P < 0.05).

Comparison of semen quality in older and younger men attending an andrology clinic

The effects of age on semen quality were analysed in patients referred to an andrology outpatient clinic in a retrospective study covering a period of 3 years. Semen analyses of older men (n = 66; > or = 50 years; median: 53) were compared with those of young patients (n = 134; 21-25 years; median 24). The duration of sexual abstinence was longer among older patients (median: 5.5 vs. 5.0 days; + 10%, P < 0.05). Even after adjustment for duration of sexual abstinence, progressive motility (- 27%, P < 0.01), percentage of morphologically normal spermatozoa (- 44%, P < 0.01) and semen volume (- 29%, P < 0.0005) were significantly lower in older than in younger men. Impaired sperm morphology was mainly attributed to abnormal staining of flagella (+ 50%, P < 0.05) and an increased portion of coiled or bent tails (+ 44%, P = 0.001) indicating epididymal dysfunction. Total sperm count and sperm concentration were unaffected by age. Age-dependent changes in accessory gland function, as indicated by fructose concentration (- 27%, P < 0.05), was correlated with lower semen volume. Moreover, serum testosterone levels were significantly reduced in the group of older men (median: 3.0 vs. 3.6 ng ml-1; -17%, P < 0.005).

[Fever as etiology of temporary infertility in the man]

BACKGROUND AND OBJECTIVE

Fever of > or = 39 degrees C for > or = 3 days can lead to severely impaired semen quality and even azoospermia. Among spermatogenic cells, pachytene spermatocytes and spermatids are particularly sensitive to temperature. Because of the nature of a spermatogenic cycle, impairment of semen quality becomes obvious after a latent period of several weeks. The changes are usually reversible within a few months. Therefore, a careful history with regard to fever episodes during preceding 3 months is mandatory for interpretation of semen analysis.

PATIENTS/METHODS

Five patients are reported who desired a child and had experienced high fever of > or = 39 degrees C for > or = 3 days. The results of semen analyses are presented in relation to fever episodes.

RESULTS

Sperm concentration declined to 0.4-7% and fast progressive motility to 0-23% 3-6 weeks after the fever episodes and returned to base line levels within 4-6 months. In patients without semen analysis before the fever episode, semen quality remarkably improved thereafter.

CONCLUSIONS

Investigating patients for a history of fever during the 3 months preceding fertility work-up avoids unreasonable treatment recommendations based on transient impairment of semen quality.

Efficacy testing of antimycotic prophylactics in an animal model

Trichophyton mentagrophytes is both zoophilic and a common causative organism in human dermatomycosis. Therefore this dermatophyte is widely used for experimental efficacy testing of antimycotic agents and their active ingredients. The use of the guinea pig as an animal model for dermatomycosis is based on the predisposition of this species to spontaneous dermal fungal infections. A previously described guinea pig model was modified according to the results of pilot experiments. The modification consists of 1) evaluation of the infectious activity of the primary mycotic tissue cultures obtained from patients and 2) the efficacy testing itself with treatment of the infected skin area including the continuous clinical observation for 28 days. At first the required duration of cultivation and the number of spores for a reproducible infection of all animals were determined. The following efficacy test consisted of four groups with ten animals each. Group I (control of infection) remained without further treatment after experimental infections, groups II-IV received a single treatment by spraying at the day of infection with isopropanol (70%) (negative control), water (mechanic control) and the antimycotic agent (treated group), respectively. After 28 days under continuous examination, clinical symptoms (scabs; reddening, scaliness) were statistically analyzed. The model takes into account the duration and severity of infection in order to evaluate the differences between the four groups. The experimental protocol presented allows the efficacy of antimycotic agents to be demonstrated by means of statistical analyses. As an example the results of a successful prophylactic treatment against T. mentagrophytes with the antimycotic prophylactic Laudamonium (1%) are presented.

A new CentriSwim procedure to increase the recovery of motile spermatozoa

A prospectively controlled in vitro study was performed to compare sperm concentration, sperm motility and progressive sperm motility recovered following the standard swim-up procedure and a new CentriSwim procedure. The CentriSwim procedure involves creating a centrifugal force to counteract the force of gravity during sperm swim-up procedure. Two aliquots of semen from 12 normozoospermic ejaculates and 12 laboratory-induced oligoasthenozoospermic specimens were diluted, centrifuged, and 1.0 ml of media layered over the sperm pellet. One aliquant was processed by standard swim-up technique. The other aliquant was processed by CentriSwim procedure involving centrifugation at 200 rpm on a 2-cm radius upward-directing arm, at an angle of 60 degrees for 10 min, creating roughly 0.8 g centrifugal force at room temperature (22-24 degrees C) to counteract the force of gravity. The numbers of spermatozoa recovered from the upper 0.5 ml of the medium following CentriSwim from the normozoospermic ejaculates and laboratory-induced oligoasthenozoospermic specimens were significantly higher than following standard swim-up procedure. No statistical differences in the recovery of percentage sperm motility and progressive sperm motility between the two techniques were observed. In conclusion, the CentriSwim procedure yields higher numbers of motile spermatozoa than the standard swim-up technique.

Mutations at the mitochondrial DNA polymerase (POLG) locus associated with male infertility

Human mitochondrial DNA polymerase, encoded by POLG, contains a polyglutamine tract encoded by a CAG microsatellite repeat. Analysis of POLG genotypes in different populations identified an association between absence of the common, ten-repeat allele and male infertility typified by a range of sperm quality defects but excluding azoospermia.

Frequency and spectrum of Malassezia yeasts in the area of the prepuce and glans penis

OBJECTIVE

To investigate the frequency and spectrum of lipophilic Malassezia yeasts within the area of the glans penis and preputial space in healthy men, most of whom were uncircumcised.

SUBJECTS AND METHODS

As the glans penis and the prepuce are abundant in sebaceous glands, 130 clinically healthy men were examined for the presence of Malassezia spp. Two impression preparations each were made on modified Dixon (mDixon) and Leeming-Notman agar. The media were used with no added cycloheximide to allow the identification of the full spectrum of Candida yeasts. After 10 days of incubation at 32 degrees C Malassezia and Candida yeasts were differentiated by micromorphological and biochemical criteria.

RESULTS

Malassezia spp. were found as part of the microflora of the glans penis in 49% of the men. The two media yielded comparable results for isolation frequency and spectrum: On mDixon agar, 47.6% of the isolates were identified as M. sympodialis, 42.8% as M. globosa, 4.8% as M. pachydermatis and 2.4% as M. furfur. Candida spp. (especially C. albicans) were found in 20.8%. There were no significant differences in the distribution of different Malassezia spp with age.

CONCLUSIONS

Malassezia yeasts may belong to the resident microflora of the male genital region, which is supported by the finding that free sebaceous glands ('Tyson's glands') normally occur at this site. They may also be involved in pathological processes of the glans penis, e.g. balanitis, seborrheic eczema or psoriasis.

[Rare cutaneous manifestaions of lupus erythematosus. A clinical overview]

Lupus erythematosus (LE) is a disease with a wide spectrum of cutaneous and systemic manifestations and has been the subject of many studies over several decades. Clinical features of patients with LE show a great variation, and for this reason it is difficult to develop a unifying concept of this disease. Consequently, this has led to the identification of subsets which have been defined by constellations of clinical and photobiological features, histological changes as well as laboratory abnormalities. Besides the characteristic classical forms such as systemic LE (SLE), subacute cutaneous LE (SCLE), and discoid LE (DLE), there are uncommon variants of LE which often lead to diagnostic difficulties. Bullous LE (BLE) and urticarial vasculitis are listed as characteristic but non-specific manifestations of systemic LE. LE tumidus (LET), LE hypertrophic/verrucous (LEHV), chilblain LE, and LE profundus (LEP) are uncommon subtypes of chronic cutaneous LE. Annular erythema and papulonodular mucinosis are further uncommon cutaneous manifestations of LE. This clinical review summarizes the typical features of the uncommon forms of LE in order to improve clinical diagnostic precision and to achieve a better differentiation of the subtypes.

[Is nature fighting back? Environmental poisons as reproduction inhibitors]

Environmental noxae may impair male fertility. Different compartments and types of cell must be considered as possible targets for drugs, such lifestyle factors as alcohol and smoking, and various environmental and occupational agents. However, the mechanisms of action in humans are known for only a limited number of noxae. For the clinical andrologist, the identification of relevant exposure to reproductive toxicants by careful history-taking remains of great importance. Nevertheless, evaluation of the relevant risks in the individual is often not possible.

Effect of two complex platinum salts on human sperm motility and acrosome reaction

Hydrogen hexachloroplatinate, H2PtCl6, has been shown to induce the human sperm acrosome reaction in vitro. However, the molecular mechanism underlying this exocytic process has not been studied. Therefore, two structurally and chemically different platinum (Pt) compounds, the potent sensitizer sodium-hexachloro-platinate-(IV), Na2[PtCl6], and the nonimmunogenic tetraamineplatinum-(II)-chloride, [Pt(NH3)4]Cl2, were selected for the experiments. Their effects on human sperm function and second messenger pathways were investigated. Washed human spermatozoa were treated with different concentrations of both Pt salts (0.5-1000 microM) during or after capacitation for 3 h at 37 degrees C. In addition, spermatozoa were incubated with Pt salts in calcium-free medium or in the presence of the protein kinase A+C inhibitor H7. Sperm motility was evaluated by computer-assisted sperm analysis; acrosomal loss was detected by triple staining. Compared with the controls (6.6+/-2.4%), the percentages of living acrosome-reacted spermatozoa showed a significant dose-dependent increase (P<0.001) after 3 h of incubation with Na2[PtCl6] (7.9+/-4.2% for 0.5 microM 25.0+/-2.9% for 1 mM) and [Pt(NH3)4]Cl2 (7.9+/-3.9% to 21.0+/-5.8%). Sperm motility was markedly reduced in samples containing the highest concentrations of the Pt salts. The acrosome reaction was also significantly increased when spermatozoa had first been capacitated and then treated with both Pt salts. Calcium-free medium had no effect on the ability of both Pt salts to induce the acrosome reaction. However, incubation of Na2[PtCl6] in the presence of H7 tendentiously decreased the percentage of acrosome-reacted spermatozoa. In conclusion, complex Pt salts such as Na2[PtCl6] or [Pt(NH3)4]Cl2 influence human sperm functions by inducing the acrosome reaction during or after capacitation. This stimulatory effect is independent of calcium and seems to be dependent on protein kinase A or C.

Xenobiotic metabolism, genetic polymorphisms and male infertility

Male reproductive function may be impaired by various occupational and environmental chemical agents. The majority of these xenobiotics, however, require metabolic activation in order to exert adverse effects via covalent interactions between intermediate metabolites and cellular macromolecules such as DNA or protein. In addition, metabolization may alter endocrine-disrupting properties of xenobiotics. Thus tissue-specific expression and regulation of multiple xenobiotic-metabolizing enzymes are likely to play an important role in chemically induced disorders of male reproductive organs. Recent studies suggest that genetic polymorphisms underlying inter-individual and inter-ethnic variability of xenobiotic metabolism modulate susceptibility to male reproductive disorders. For cytochrome P450 1A1 (CYP1A1), a key enzyme in extra-hepatic metabolic activation of lipophilic xenobiotics, increased frequencies of two genetically linked polymorphisms have been found among infertile men.

Pyoderma gangrenosum after cesarean delivery

In this reported case of pyoderma gangrenosum after cesarean delivery, deep ulceration involved the entire lower abdomen before immunosuppressive treatment was started. Initial high doses of prednisolone followed by low doses of cyclosporine A led to complete resolution of the skin lesions. This case report illustrates the importance of early diagnosis and effective systemic immunosuppressive therapy of pyoderma gangrenosum.

[Annular erythema in Sjögren syndrome. A variant of cutaneous lupus erythematosus?]

Annular erythema has been recognised as a cutaneous manifestation of Sjögren's syndrome in the Asian literature and has been assumed to represent a distinct clinical entity. Since there are common pathophysiologic mechanisms, mainly the presence of anti-Ro/SSA or anti-La/SSB antibodies, it is difficult to separate the annular erythema from subacute cutaneous lupus erythematosus. Histological examination may reveal dermal mucin deposition resembling lupus erythematosus tumidus. We present a Chinese patient with widespread annular erythema, keratoconjunctivitis sicca, and anti-Ro/SSA antibodies. Clinical, histopathological, and immunogenetic findings are discussed reviewing the current literature, and the differences between annular erythema associated with Sjögren's syndrome and cutaneous lupus erythematosus are emphasized.

[Combination of antimalarial drugs mepacrine and chloroquine in therapy refractory cutaneous lupus erythematosus]

Antimalarials represent the first line in treatment of cutaneous lupus erythematosus (LE). However, some patients show no improvement on monotherapy with chloroquine or hydroxychloroquine. A 30-year-old female patient had treatment-resistant cutaneous LE exhibiting features of both LE tumidus and subacute cutaneous LE. Previously, the patient had been unsuccessfully treated with chloroquine, hydroxychloroquine, dapsone, and azathioprine, each in combination with variable doses of prednisolone. However, the LE lesions increased during these therapeutic regimens. A combination of chloroquine and mepacrine therapy led to improvement and then total clearing after 4 months of treatment.

Polymorphisms of the xenobiotic-metabolizing enzymes CYP1A1 and NAT-2 in systemic sclerosis and lupus erythematosus

The etiology of systemic autoimmune diseases, such as systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is still unknown. In several cases, however, xenobiotics (i.e. drugs and occupational agents) were identified as etiologic agents and associations with certain polymorphic alleles of xenobiotic-metabolizing enzymes have been reported. Cytochrome P4501A1 (CYP1A1) and N-acetyltransferase 2 (NAT-2) are xenobiotic-metabolizing enzymes of phase 1- and phase 2-metabolism, respectively. CYP1A1 may activate drugs and other chemicals to reactive metabolites. NAT-2 is the most important enzyme in acetylation of aromatic amines, and thus may be responsible for detoxification of many of these compounds. Two polymorphisms of the human CYP1A1 gene, a point mutation in the 3' flanking region of the gene (Msp1) and a mutation in exon 7 leading to an isoleucine-valine-exchange in the heme-binding region of the enzyme, have been described and may lead to a higher basal and inducible enzyme activity. With respect to NAT-2, several alleles which combine for the two phenotypes "fast" and "slow" acetylators have been described. We analyzed the gene frequencies of the CYP1A1 polymorphisms and the phenotypes of NAT-2 in patients suffering from idiopathic SLE or SSc. CYP1A1 polymorphisms were analyzed in genomic DNA by PCR, whereas NAT-2 phenotypes were measured by the caffeine method. For CYP1A1 polymorphisms, 106 patients have been typed until now. The SLE group (n = 68) exhibited a significant increase (p < 0.05) in the mutant Val-allele (OR = 2.59) when compared to controls (n = 184). However, no significant differences in allele frequencies for MspI in the SLE group and for both CYP1A1 polymorphisms in the SSc group could be observed. Regarding the NAT-2 phenotype, patients suffering from SLE (n = 88) 75% and SSc (n = 26) 80.2%, respectively, were slow acetylators compared to 55% slow acetylators in the healthy German population (p < 0.05). The observed increased frequencies of the CYP1A1 mutant Val-allele and the slow actylator phenotype in idiopathic autoimmune disease support our concept that in slow acetylators non-acetylated xenobiotics may accumulate and are subsequently metabolized by other enzymes into reactive intermediates. Thus, enhanced formation of reactive metabolites could alter self-proteins presented to the immune system thus stimulating autoreactive T cells which induce autoimmunity.

Secondary infertility as early symptom in a man with multiple endocrine neoplasia-type 1

Multiple endocrine neoplasia-type 1 (MEN1) is an autosomal dominant familial cancer syndrome characterized by parathyroid hyperplasia, pancreatic endocrine tumours and pituitary adenomas. Here, we report a patient with a history of insulinoma who developed secondary infertility as a further symptom of the disease. When he was first examined at the age of 36 years, he complained of weakness, reduced libido and impotence. Laboratory evaluation revealed non-obstructive azoospermia and hyperprolactinaemia. In contrast to sexual activity and serum prolactin, semen quality did not significantly respond to bromocriptine therapy. During follow-up, a growing pituitary adenoma caused acromegaly with elevated serum concentrations of growth hormone, insulin-like growth factor 1 (IGF-1), and prolactin. After microsurgery of the tumour at the age of 44 years, sperm concentration persistently increased up to 5.6 x 10(6)/ml. In accordance with the clinical diagnosis of MEN1, DNA sequencing revealed a mutation in exon 2 of the menin gene which results in a truncated, inactive protein product. In conclusion, MEN1 with pituitary lesions may cause severe hypogonadism and infertility. Both hyperprolactinaemia and overproduction of growth hormone and IGF-1 seem to be involved in testicular dysfunction in the present case. The possible role of menin in the testis, however, remains to be elucidated.

[Scabies--provoked bullous lichen planus in a child]

Lichen ruber planus is considered a T-cell mediated immunologic reaction with unclear pathogenesis. Drugs and infections (especially hepatitis B and C) are well-known provocation factors. After an infection with scabies a 13 year old boy developed a generalized lichen planus including bullous lesions. For the first time scabies is presented as a trigger for lichen planus. In childhood, lichen planus is characterized by atypical clinical features and sometimes a severe course.

An integrated model for the differentiation of chemical-induced allergic and irritant skin reactions

Contact and photocontact allergic as well as irritant and photoirritant skin reactions represent a major problem in clinical dermatology and during the development of new pharmaceuticals. Furthermore, there is a lack of in vitro and in vivo assays that provide a clear differentiation between allergic and irritant skin reactions. Here, we describe an integrated model to differentiate between chemical-induced allergic and irritant skin reactions by measuring objective and easy-to-determine parameters within both skin and skin-draining lymph nodes. Dose-response studies with standard contact and photocontact allergens as well as irritants and photoirritants revealed that irritants predominantly induced skin inflammation, which in turn stimulated draining lymph node cell proliferation. In contrast, the induction phase of contact or photocontact allergy was characterized by marginal skin inflammation, but a marked activation and proliferation of skin-draining lymph node cells. Therefore, a differentiation index (DI) was defined describing the relation between skin-draining lymph node cell activation (lymph node cell count index) and skin inflammation (ear swelling). A DI > 1 indicates an allergic reaction pattern whereas DI < 1 demonstrates an irritant potential of a chemical. Experiments with the contact allergen oxazolone, the photocontact allergen TCSA + UVA, the irritant croton oil, and the photoirritant 8-methoxypsoralen + UVA confirmed the predictive value of DI. Furthermore, flow cytometric analysis of lymph node-derived T- and B-cell subpopulations revealed that contact sensitizer, but not irritant, induced the expression of CD69 on the surface of I-A+ cells. In conclusion, further studies with a broad range of irritants and allergens will be required to confirm general applicability.

Topical FK506 suppresses cytokine and costimulatory molecule expression in epidermal and local draining lymph node cells during primary skin immune responses

Recently, it has been shown that the immunosuppressive macrolide lactone, FK506, exerts good therapeutic efficacy in inflammatory skin diseases. The aim of this study was to analyze the influence of topical FK506 on molecular (IL-1alpha, IL-1beta, IL-2, IL-4, IL-12 p35, IL-12 p40, macrophage inflammatory protein-2 (MIP-2), granulocyte-macrophage CSF (GM-CSF), TNF-alpha, and IFN-gamma) and cellular (I-A+/CD80+, I-A+/CD54+, I-A+/CD69+, I-A+/B220+, and CD4+/CD25+) events in epidermal (EC) and local draining lymph node (LNC) cells during primary contact hypersensitivity responses. Cytokine mRNA levels for IL-1alpha, IL-1beta, GM-CSF, TNF-alpha, MIP-2, and IFN-gamma in EC and for IL-2, IL-4, IL-12 p35, IL-12 p40, and IFN-gamma in LNC were increased and resulted in significant LNC proliferation during oxazolone-induced contact hypersensitivity. Topical FK506 treatment dose-dependently suppressed oxazolone-induced LNC proliferation. This effect was correlated with decreased IL-1alpha, IL-1beta, GM-CSF, TNF-alpha, MIP-2, and IFN-gamma mRNA expression within the epidermis and decreased IL-12 p35 and p40 mRNA expression in LNC. Further analysis of the LNC cytokine pattern revealed that the production of both Thl (IFN-gamma and IL-2) and Th2 (IL-4) cytokines was dramatically impaired after topical FK506 treatment. Flow cytometric analysis showed that topical FK506 decreased the population of epidermis-infiltrating CD4+ T cells and suppressed the expression of CD54 and CD80 on I-A+ EC and LNC during hapten-induced contact hypersensitivity. Furthermore, topical FK506 profoundly impaired oxazolone-induced up-regulation of CD25 expression on CD4+ LNC and dramatically decreased hapten-induced expansion of I-A+/B220+ and I-A+/CD69+ LNC subsets. In conclusion, these results give new insights into the mechanisms of action of topical FK506 treatment.

Increased frequencies of cytochrome P4501A1 polymorphisms in infertile men

Genetic factors that could mediate the pathogenesis of male reproductive disorders are largely unclear. Polymorphisms of cytochrome P4501A1 (CYP1A1), a key enzyme in the extrahepatic metabolism of lipophilic xenobiotics, have been shown to influence susceptibility to xenobiotics. Here, CYP1A1 polymorphisms were investigated in 134 infertile Caucasian men. The frequencies of the Mspl polymorphism in the 3'-flanking region of the CYP1A1 gene and a mutation in exon 7 causing an isoleucine-valine exchange (IVE) in the heme-binding region of the enzyme were increased among infertile men when compared with those of unselected, healthy male controls (odds ratio (OR)) 1.4, Cl95 0.68-2.89 for Mspl polymorphism; OR 2.4, Cl95 0.83-6.95 for IVE). Patients with normozoospermia revealed the highest frequencies for both polymorphisms (n = 8; OR 4.5, Cl95 0.97-20.91 for Mspl polymorphism; OR 13.7, Cl95 2.53-74.13 for IVE). ORs for the IVE exceeded the values calculated for the Mspl polymorphism. These preliminary results suggest that genetic variation in the metabolism of xenobiotics may codetermine individual susceptibility to infertility.