Molecular and clinical characterization of Y chromosome microdeletions in infertile men: a 10-year experience in Italy

CONTEXT: An explosive growth in Y chromosome long arm (Yq) microdeletion testing demand for male infertility occurred in the past few years. However, despite the progresses in the biology of this chromosome, a number of molecular and clinical concerns are not supported by definitive data. OBJECTIVE: The objective was to provide information on the type and prevalence of microdeletions in infertile males, indication for testing, genotype-phenotype correlation, sperm aneuploidies, and genetic counseling. DESIGN AND SETTING: We performed a prospective study from January 1996 to December 2005 in an academic clinic. PATIENTS: We studied 3073 consecutive infertile men, of which 625 were affected by nonobstructive azoospermia and 1372 were affected by severe oligozoospermia. Ninety-nine patients with microdeletions are described here. MAIN OUTCOME MEASURES: Yq microdeletions, seminal analysis, reproductive hormones, testicular cytology/histology, and sperm sex chromosomes aneuploidies were used as outcome measures. RESULTS: The prevalence of microdeletions was 3.2% in unselected infertile men, 8.3% in men with nonobstructive azoospermia, and 5.5% in men with severe oligozoospermia. Only 2 of 99 deletions were found in men with more than 2 million sperm/ml. No clinical data are useful to identify a priori patients with higher risk of Yq microdeletions. Most deletions are of the AZFc-b2/b4 subtype and are associated with variable spermatogenic phenotype, with sperm present in 72% of the cases. Complete AZFa and AZFb (P5/Proximal P1) deletions are associated with Sertoli cell-only syndrome and alterations in spermatocyte maturation, respectively, whereas partial deletions in these regions are associated with milder phenotype and frequent presence of sperm. Men with AZFc-b2/b4 deletions produce a higher percentage of sperm with nullisomy for the sex chromosomes and XY-disomy. CONCLUSIONS: This extensive clinical research expands the knowledge on genotype-phenotype relationships and confirms that the identification of Yq microdeletions has significant diagnostic and prognostic value, adding useful information for genetic counseling in these patients.     

Nyctohemeral growth hormone profiles in young and aged men: correlation with somatomedin-C levels

The effects of aging on GH secretion and somatomedin-C (SM-C) levels were studied in 10 young (22-45 yr) and 10 elderly (65-85 yr) men. Plasma GH levels were measured in samples obtained at 20-min intervals for 1300 min. Plasma SM-C levels were measured in samples obtained at 0600, 1100, 1600, 2100, and 0200 h. In the elderly men the mean basal plasma GH level was similar to that in the young men, but the total GH peak area as well as the amplitude of the peaks were significantly (p less than 0.01) lower than those in young men during both the day and the night. Plasma SM-C levels were significantly lower in the elderly men and were correlated with the total integrated GH levels and total GH peak areas, but not with basal plasma GH levels, suggesting that the GH peaks determine SM-C levels and that the decreased GH secretion in elderly men has biological significance.     

Sertoli cell function in infertile patients with and without microdeletions of the azoospermia factors on the Y chromosome long arm

Deletions of the azoospermia factors on the Y chromosome long arm are an important cause of male infertility, and they may involve germ cell-specific genes or ubiquitously expressed genes. To date, no clinical or hormonal parameters have yet been found to distinguish patients with and without Yq microdeletions. In particular, Sertoli cell function, as evaluated by inhibin B, has not yet been described. Our hypothesis was that microdeletions involving genes specifically expressed in germ cells should not alter Sertoli cell function. To do this, we have evaluated the testicular hormonal function in infertile patients affected by severe testiculopathies with and without Yq microdeletions, with particular emphasis on Sertoli cell function. We studied 102 well-characterized infertile patients; 27 had Yq microdeletions, and 75 were classified as idiopathic infertiles. Patients with Yq microdeletions had lower FSH and higher inhibin B plasma concentrations with respect to patients without microdeletions, suggesting that Sertoli cell function in Yq-deleted men is only partially altered. Furthermore, patients with deletions involving germ cell-specific genes had higher concentrations of inhibin B with respect to patients with deletions of ubiquitously expressed genes. These results suggested that a specific alteration of germ cells only partially influences Sertoli cell function. Hormonal status of patients without deletions suggested that in such cases the cause that has determined the spermatogenic defect may have damaged both Sertoli and germ cells. Inhibin B production in patients with Yq deletions was about 70% higher than the nondeleted patients, and the functional relationship between FSH and inhibin B was normally preserved. This study elucidated the multifactorial mechanisms underlying spermatogenic defects, where Sertoli cells may be normally functioning or damaged depending on the primary cause that has determined the testicular damage.     

Hormonal parameters and sex hormone receptor gene polymorphisms in men with autoimmune diseases

Autoimmune diseases (ADs) are more common in women than in men. Sex hormones may play a role. Sex hormone receptors (SHR) are expressed in cells of the immune system. We investigated the possible role of hormonal parameters and of common polymorphisms of the estrogen receptor alpha (ESR1), beta (ESR2), and androgen receptor (AR) genes in the appearance of AD in men. 277 men were studied; 125 with ≥1 AD: Hashimoto’s autoimmune thyroiditis (n = 65), Graves’ disease (n = 12), SLE (n = 10), and RA (n = 38). 152 were controls. Hormonal and biochemical parameters were measured after discontinuation for ≥1 month of any corticosteroid therapy. ESR1 PvuII, ESR2 AluI, and the AR (CAG)n repeats polymorphisms were analyzed. AD patients had higher estradiol levels (31.32 ± 12.10, controls 20.37 ± 7.91 pg/ml, p < 0.001). In multivariate analysis, significant predictors for AD were estrogen and BMI. The allele frequency of ESR1 PvuII and ESR2 AluI did not differ between patients and controls (AD: 47.8 %, 37.6 %; controls 49.8 %, 39.9 %). The distribution of (CAG)n did not differ between groups. In AD group, shorter (CAG)n alleles were associated with younger age of AD onset (short: 38.52 ± 14.8, long: 47.14 ± 17.34 years, p = 0.048). Carriers of ESR1 PvuII presented less frequently ≥2 AD (carriers 6.5 %, non-carriers 25.1 %, p = 0.019); carriers of AluI had lower SHBG levels and higher ΒΜΙ compared to non-carriers (p < 0.04). Higher estradiol may play a role in AD in men. Distribution of SHR gene polymorphisms is similar between patients and controls. Shorter AR (CAG)n repeats may predispose for younger AD onset. Coexistence of ≥2 AD is less frequent in carriers of ESR1 PvuII. ESR2 AluI may adversely affect obesity parameters.     

Male adiposity,sperm parameters and reproductive hormones: An updated systematic review and collaborative meta‐analysis

The present updated systematic review and meta‐analysis aims to summarize the evidence from published studies with low risk for any important bias (based on methodological quality assessment) investigating the potential associations of adiposity with sperm quality and reproductive hormones. We conducted a systematic search of the literature published in MEDLINE‐PubMed and EMBASE through June 2019. Based on the criteria in our review, 169 eligible publications were used for data abstraction. Finally, 60 articles were included in the qualitative analysis and 28 in the quantitative analysis. Our systematic review results indicated that overweight and/or obesity were associated with low semen quality parameters (i.e., semen volume, sperm count and concentration, sperm vitality and normal morphology) and some specific reproductive hormones (e.g., inhibin B, total testosterone and sex hormone‐binding globulin). Overweight and/or obesity were also positively associated with high estradiol concentrations. Meta‐analysis indicated that overweight and/or obesity categories were associated with lower sperm quality (i.e., semen volume, sperm count and concentration, sperm vitality, total motility and normal morphology), and underweight category was likewise associated with low sperm normal morphology. In conclusion, our results suggest that maintaining a healthy body weight is important for increasing sperm quality parameters and potentially male fertility.     

Relationship of serum inhibin levels to serum follicle stimulating hormone and sperm production in normal men and men with varicoceles.

The purpose of this study was to examine the relationships between serum inhibin levels as measured by RIA and serum FSH and sperm concentration. Three groups of men were used for this study: group I, normal fertile men (n = 67); group II, fertile men with a varicocele (n = 57); and group III, infertile men with a varicocele (n = 21). There were no differences in mean serum inhibin levels between the three groups. The two groups of men with varicoceles exhibited higher serum FSH levels and FSH responses to GnRH than the normal men. Sperm counts in both groups II and III were significantly lower than group I. In the normal men there was an inverse correlation between baseline serum inhibin and serum FSH levels and GnRH stimulated FSH levels, r = -0.415 and 0.422, P less than 0.005, respectively. Furthermore, the normal men exhibited a positive correlation between serum inhibin measurements and sperm concentration and testicular volume, r = 0.35 and 0.26, P less than 0.01 and less than 0.05, respectively. In neither group of men with a varicocele were these relationships found. These data demonstrate that serum inhibin does correlate with FSH in a negative fashion, when the reproductive system is normal, as would be expected for a negative feedback factor. Finally, the relationship of serum inhibin levels to testicular size and sperm count in the normal men suggests that serum inhibin levels reflect to some extent the integrity of seminiferous tubule function.     

Pleiotropy in microdeletion syndromes: neurologic and spermatogenic abnormalities in mice homozygous for the p6H deletion are likely due to dysfunction of a single gene.

Variability and complexity of phenotypes observed in microdeletion syndromes can be due to deletion of a single gene whose product participates in several aspects of development or can be due to the deletion of a number of tightly linked genes, each adding its own effect to the syndrome. The p6H deletion in mouse chromosome 7 presents a good model with which to address this question of multigene vs. single-gene pleiotropy. Mice homozygous for the p6H deletion are diluted in pigmentation, are smaller than their littermates, and manifest a nervous jerky-gait phenotype. Male homozygotes are sterile and exhibit profound abnormalities in spermiogenesis. By using N-ethyl-N-nitrosourea (EtNU) mutagenesis and a breeding protocol designed to recover recessive mutations expressed hemizygously opposite a large p-locus deletion, we have generated three noncomplementing mutations that map to the p6H deletion. Each of these EtNU-induced mutations has adverse effects on the size, nervous behavior, and progression of spermiogenesis that characterize p6H deletion homozygotes. Because EtNU is thought to induce primarily intragenic (point) mutations in mouse stem-cell spermatogonia, we propose that the trio of phenotypes (runtiness, nervous jerky gait, and male sterility) expressed in p6H deletion homozygotes is the result of deletion of a single highly pleiotropic gene. We also predict that a homologous single locus, quite possibly tightly linked and distal to the D15S12 (P) locus in human chromosome 15q11-q13, may be associated with similar developmental abnormalities in humans.     

Short-term suppression of GH and IGF-I levels improves gonadal function and sperm parameters in men with acromegaly

Experimental data support a role for GH and IGF-I in the reproductive process in humans, but the effect of chronic GH excess on gonadal and reproductive function in men has been never investigated. To understand the effects of short-term GH and IGF-I suppression on the gonadal axis and seminal fluid characteristics in men with acromegaly, we evaluated 35 patients (age 27-59 yr) with active disease and 35 age-matched healthy controls. Gonadal hormones and seminal fluid analysis were evaluated before and 6 months after surgery or lanreotide (LAN) (60 mg/month). At study entry, FSH, testosterone (T), and dihydrotestosterone (DHT) (P < 0.0001) levels, seminal volume, sperm count, total motility and forward progression, normal morphology, and vitality were significantly lower in patients with acromegaly than in controls. After 6 months, 22 patients achieved disease control after surgery (n = 11) or LAN (n = 11), whereas 13 had uncontrolled disease. Serum T and DHT levels and sperm number significantly increased in all groups. FSH and LH levels and total motility increased only in patients achieving disease control. Posttreatment IGF-I levels significantly correlated with total motility (r = -0.45; P = 0.006). In conclusion, short-term GH and IGF-I suppression after surgery or LAN significantly increased T and DHT levels and improved sperm number and motility in acromegalic men.     

Correlations of Y chromosome microchimerism with disease activity in patients with SLE: analysis of preliminary data

BACKGROUND: Recently it has been suggested that microchimerism may have a significant role in the aetiopathogenesis of some autoimmune diseases. OBJECTIVES: To evaluate the incidence of microchimerism in systemic lupus erythematosus (SLE), to quantify the phenomenon, to evaluate changes of microchimerism during follow up, and to correlate these data with clinical and laboratory variables. METHODS: Patients were selected for the study on the basis of the following criteria: (a) pregnancy with at least one male offspring; (b) no history of abortion and blood transfusion. Microchimerism was detected using a competitive nested polymerase chain reaction for a specific Y chromosome sequence and an internal competitor designed ad hoc. Disease activity and organ involvement were also evaluated. RESULTS: Sixty samples from 22 patients with SLE and 24 healthy controls were examined. Microchimerism was seen in 11 (50%) patients and 12 (50%) controls. The mean number of male equivalent cells was 2.4 cells/100 000 (range 0.1-17) in patients with SLE and 2.5 (range 0.2-1.8) in healthy controls. No differences in the incidence of microchimerism or in the number of microchimeric cells were found between patients and healthy controls. Patients with a history of lupus nephritis had a higher mean number of fetal cells than patients with no such history. Disease activity did not appear to correlate with microchimerism. CONCLUSIONS: The preliminary data suggest that microchimerism does not interfere with the disease course of SLE, although further analysis on larger groups will be necessary to confirm these observations.     

Luteinizing hormone pulsatility and computer-assisted analysis of sperm features in patients with Hodgkin's disease

The aim of this work was to characterize further the impairment of the reproductive function reported in untreated male patients with Hodgkin's disease. We evaluated the pattern of luteinizing hormone pulsatility and unconventional sperm features by computer-assisted sperm analysis (CASA) in 20 adult patients affected by biopsy-proven Hodgkin's disease before they were submitted to any therapeutic approach. Changes of luteinizing hormone pulsatility were documented and consisted mainly in an increase in pulse number in comparison with control subjects (P<0.05). On CASA, 1/3 of the patients showed a reduction in the sperm number but, when motility, velocity and linearity of progression were evaluated, the number of patients with seminal alterations rose to 2/3. Sperm velocity and linearity were already impaired in stages I and II, whereas sperm number was reduced only in stage III. Symptomatic patients, regardless of the stage, showed a significant deterioration of all parameters. Our study supports the view that in Hodgkin's disease, before any treatment, a disorder of the reproductive system is present, both at hypothalamic/hypophysial and the gonadal level, having a pathogenesis that deserves to be elucidated by further study.Abbreviations HD Hodgin's disease - LH luteinizing hormone     

Acquired growth hormone resistance in patients with chronic heart failure: implications for therapy with growth hormone

OBJECTIVES: We aimed to determine whether growth hormone (GH) resistance is present in patients with chronic heart failure (CHF) and whether it may be linked to the biochemical response to GH treatment. BACKGROUND: Acquired GH resistance is a feature of severe illness, in particular, cachexia. In patients with CHF, the response to GH therapy appears to be variable. METHODS: Biochemical markers of the GH-insulin-like growth factor-I (IGF-I) axis were compared in 21 cachectic patients with CHF, 51 noncachectic patients and 26 healthy control subjects. In separate studies, the predictive value of baseline biochemical variables for the IGF-I response to GH treatment was analyzed. RESULTS: Cachectic patients showed an increase of total GH and immunologically intact GH (p < or = 0.0002) and a decrease of GH-binding protein (BP) (p = 0.005), IGF-BP3 (p = 0.01) and IGF-I (p = 0.06), compared with noncachectic patients. Similar changes were found when the cachectic group was compared with the control group. No differences were found between noncachectic patients and control subjects. Levels of GH-BP correlated with the IGF-I/GH ratio in all subgroups (all p < or = 0.002). Baseline GH-BP levels were related to the increase of IGF-I levels in response to GH treatment in patients with CHF after 24 h (r = 0.83, p = 0.005; n = 9; study 2), 44 days (r = 0.52, p = 0.007; n = 25; study 3) and 96 days (r = 0.54, p = 0.006; n = 24; study 3). CONCLUSIONS: Most cachectic and some noncachectic patients with CHF show features of acquired GH resistance. The principal predictors of the biochemical features of GH resistance and of the poor biochemical response to short-term and longer-term GH treatment are GH-BP plasma levels. The presence of GH resistance is potentially a major factor determining the response to GH therapy in patients with CHF.     

Glomerular filtration rate and parathyroid hormone are associated with 1,25-dihydroxyvitamin D in men without chronic kidney disease

Abstract. Karhapää P, Pihlajamäki J, Pörsti I, Kastarinen M, Mustonen J, Niemelä O, Tuomi H, Kuusisto J (University of Eastern Finland, Kuopio; University of Tampere, Tampere; Finnish Medical Agency, Kuopio; and University of Tampere, Tampere, Finland). Glomerular filtration rate and parathyroid hormone are associated with 1,25‐dihydroxyvitamin D in men without chronic kidney disease. J Intern Med 2012; 271 : 573–580. Background and aim. Vitamin D, estimated glomerular filtration rate (eGFR) and parathyroid hormone (PTH) are related to cardiovascular disease risk. We examined the associations between the levels of 25‐hydroxyvitamin D (25‐D) and 1,25‐dihydroxyvitamin D (1,25‐D) and both eGFR and PTH. Design and setting. Cross‐sectional population‐based study in Kuopio, Eastern Finland. Subjects. A total of 909 men without known chronic kidney disease (CKD) and not receiving antidiabetic medication, aged from 45 to 73 years, were included in the study. Main outcome measures. Fasting levels of 25‐D, 1,25‐D, creatinine and PTH were measured, and an oral glucose tolerance test (OGTT) was performed. Results. High levels of 25‐D were associated with low levels of eGFR and PTH (β = ?0.17, P = 9 × 10^?7 and β = ?0.28, P = 6 × 10^?17, respectively, adjusted for age, body mass index and levels of calcium, phosphorus and glucose in a 2‐h OGTT, and also for either eGFR or PTH). By contrast, high 1,25‐D levels were associated with high levels of eGFR and PTH (β = 0.17, P = 2 × 10^?6 and β = 0.19, P = 5 × 10^?8, respectively, adjusted as mentioned earlier and additionally for 25‐D). Eighteen per cent of men in the highest 25‐D quartile were in the lowest 1,25‐D quartile and also had a lower eGFR than men with high levels of both 25‐D and 1,25‐D (P = 4 × 10^?5). Finally, 15% of men in the lowest 25‐D quartile were in the highest 1,25‐D quartile and also had higher PTH levels than men with low levels of both 25‐D and 1,25‐D (P = 2 × 10^?3). Conclusion. Our findings suggest that both eGFR and PTH are significantly associated with vitamin D metabolism in men without known CKD.     

Effect of growth hormone administration frequency on 24-hour growth hormone profiles and levels of other growth related parameters in girls with Turner's syndrome*

OBJECTIVE The optimal dose and frequency of GH administration in Turner's syndrome is unknown. There is some evidence that a schedule which mimics normal pulsatile GH secretion may be more effective than a single dally dose. We therefore wished to study the influence of the frequency of GH administration on 24-hour GH profiles and levels of other growth-related factors in Turner's syndrome. DESIGN Four weeks after initiation of 005 μg/kg/day ethinyl oestradiol, we compared twice daily (b.I.d.-fractionated dose) with once daily (o.d.) s.c. injections of 6 IU GH/m2/day in a 2-week cross-over design with a 2-week washout Interval. Each treatment period was concluded with 24-hour GH profile tests. Pretreatment plasma/serum levels of GH, IGF-I, binding proteins for GH (GHBP) and IGF-I (IGFBP-3) were used as a basis for comparison of the levels found after each regimen. A one-compartment open model was used for estimation of pharmacokinetic parameters. SUBJECTS Ten previously untreated girls with Turner's syndrome aged 11 years. MEASUREMENTS Plasma levels of GHBP by standardized binding assay; GH, IGF-I, and IGFBP-3 serum/plasma levels by radioimmunoassay. RESULTS There were significantly higher maximum GH levels and a greater area under the curve with o.d. than with b.I.d. GH, while GH clearance was greater with b.I.d. The pharmacokinetic values with o.d. injections were in conformity with values for healthy and GH-deficient children. Pretreatment GHBP levels tended to be high compared with values in healthy prepubertal children. These levels decreased with GH therapy, significantly so with b.I.d. GH only. There was a significant increase in levels of IGF-I and IGFBP-3, irrespective of regimen. The IGF-I to IGFBP-3 ratio, a possible indicator of the growth response, rose significantly and comparably with both regimens. There was no consistent diurnal variation with either regimen in GHBP, IGF-I or IGFBP-3 levels. Four-hourly levels of GH, GHBP, IGF-I and IGFBP-3 were not correlated. CONCLUSIONS Although the 24-hour profiles differed during once or twice daily administration of the same total growth hormone dose, the diurnal pattern and mean levels of factors involved in the biological effects of GH are comparable for both regimens.     

Hypogonadotropic disorders in men and women: diagnosis and therapy with pulsatile gonadotropin-releasing hormone

Hypogonadotropic hypogonadism (HH) is a clinical syndrome occurring in both sexes which has long puzzled clinicians due to the apparent paradox of nonfunctioning gonads in the face of normal or only slightly lowered levels of circulating gonadotropins. Using frequent sampling of gonadotropin levels as an index of hypothalamic GnRH secretion, we have examined the hypothesis that this group of disorders represents a spectrum of abnormal patterns of the pulsatile release of endogenous GnRH. After a broad, normative data base was established in both men and women for purposes of comparison, it appears that quantifiable abnormalities of GnRH secretion are discernible in both males and females with HH. These abnormalities include a total absence of GnRH secretion, defects of the amplitude and frequency of its secretion, and altered bioactivity of the gonadotropins released. In addition, physiological regimens of hypothalamic replacement therapy with exogenous GnRH, which are fashioned to mimic the normal frequency of endogenous GnRH secretion, result in complete normalization of reproductive function and fertility in hypogonadotropic subjects of both sexes. Thus, the heterogeneous nature of HH, as well as its favorable clinical and biochemical responses to GnRH, suggest that the basic defect in this family of disorders involves a partial or complete inability to synthesize and/or release GnRH from the hypothalamus in a manner compatible with physiological reproductive function. Conversely, these findings imply that maintenance of a physiological amplitude and frequency of endogenous GnRH secretion appear to be essential for normal reproductive function.