Semen analysis of renal transplant patients undergoing immunosuppressive treatment

Abstract

Introduction The prevalence of infertility is increasing at an alarming rate globally. Many couples are afflicted with infertility due to an array of diseases, trauma and psychological stresses. Renal disease is one such pathophysiological condition which is increasing amongst the younger age group. Often the progression of chronic renal disease leads to end stage renal failure that requires a renal transplantation. Post renal transplant, immunosuppressive agents are routinely prescribed to prevent allograft rejection. Immunosuppressive agents are potent drugs that can have deleterious side effects on semen parameters. However, the effects of the immunosuppressive agents on semen parameters in the literature are unclear and require further investigation. It is, therefore, important to assess the effects of immunosuppressive agents on semen, especially the three vital aspects of sperm concentration, motility and morphology which form the basis of male reproduction.

Aims and Objectives of study This was a prospective observational study evaluating the effects of different immunosuppressive regimens on sperm parameters in post renal transplant male patients. The main aspects of semen parameters such as sperm concentration, motility and morphology that determine reproductive potential were assessed in the study patients and compared to the gold standard of semen analysis according to the World Health Organisation (WHO) reference values.

Methodology Thirty-four renal transplant patients were recruited from the databases of both private nephrologists in the greater Durban area and the academic renal unit at Inkosi Albert Luthuli Central Hospital. Following bioethical approval and informed consent, patients were required to produce a semen sample by masturbation. A questionnaire documenting the patient’s lifestyle, aetiology of renal disease, transplant date and immunosuppressive duration and regimen were recorded. The semen samples were analysed comprehensively according to the protocol on semen analysis recommended by the WHO. This included the macroscopic investigation (volume, appearance, colour, viscosity, liquefaction time and pH) and microscopic evaluation (sperm concentration, total motility, morphology, IgG/IgA and vitality). Sperm concentration, total motility, morphology and vitality were examined and recorded in duplicate to strengthen the validity of the results. A biostatistician analysed the data and determined the statistical analysis. Descriptive statistics determined values of semen parameters in renal transplanted males and in each race demographic. The one sample t-test analysed the statistical significance between the mean study values and the WHO reference values. The effect of the immunosuppressive agent on semen parameters was determined using multiple linear regressions whilst ROC analysis determined the sensitivity and specificity of sperm concentration, total motility and morphology in predicting pregnancy from the patients that fathered children post renal transplant.

Results The mean sperm concentration and morphology in the study patients were 14.0 mill/ml (95% Confidence Interval (CI) 10.2 – 17.7) and 3.3% (95% CI 2.7 – 3.9), respectively. Although values obtained were minimally lower than the WHO reference values, these results were within the 95% CI of the WHO guidelines.

Motility evaluation revealed higher values of 43.2% (95% CI 36.6 – 49.7). In contrast, sperm vitality was considerably decreased, 47.5% (95% CI 40.6 – 54.4). All semen parameters exhibited no statistical significance (one sample t-test) when analysed against the WHO reference values except for sperm morphology, (p = 0.025; p< 0.05) which showed decreased morphology irrespective of immunosuppressive regimen. Semen volume 1.7 ml (95% CI 1.3 – 2.0) and pH 7.7 (95% CI 7.6 – 7.9) were both within the WHO guidelines. Descriptive statistics according to racial demographics showed no differences in semen values. An almost perfect linear relationship existed between total sperm motility and vitality (r = 0.967). Multiple linear regressions of duration and dosages of immunosuppressive drugs tacrolimus and mycophenolate mofetil, could not predict the effect of the immunosuppressive agents on sperm concentration, total motility and morphology. There was a significant difference in morphology between those with and without children post renal transplant. Those with children post renal transplant exhibited a higher morphology value, (p = 0.001; p< 0.05). Sensitivity and specificity analysis of the patients with children post renal transplant concluded that morphology is the most optimal indicator and predictor of pregnancy (AUC = 0.854). Tacrolimus was the common immunosuppressive agent used in the four patients that fathered children. This was more evident in patients that underwent therapy with Sirolimus followed by Cyclosporin A (CsA) and changed to Tacrolimus as the last immunosuppressive agent used for maintenance therapy.

Conclusion The ability to procreate in renal transplanted males has become increasingly difficult and emotionally challenging. In this study sperm concentration and morphology of renal transplanted males exhibited parameters similar to the general fertile population. Total motility possessed a higher range of values in contrast to sperm vitality which showed a significant decrease from the WHO reference values. The effect of immunosuppressive treatment on semen parameters could not be clearly defined due to the number of immunosuppressive regimens that patients were subjected to intermittently resulting in small sample sizes within each immunosuppressive regimen grouping. The majority of patients underwent a triple maintenance therapy of tacrolimus, MMF and prednisone. The dosage and duration of these tacrolimus and MMF was inconclusive in determining a beneficial or detrimental relationship on semen parameters. Morphology was shown to be the most significant indicator in predicting pregnancy in patients that fathered children. Tacrolimus was a common immunosuppressive agent used in the majority of patients that fathered children. It may have protective effects on sperm parameters as shown in patients that fathered children. This was a study with a small sample size and further investigations are required in a larger cohort of patients to assess individualized effects of the different immunosuppressive agents on sperm parameters.