Inhibin B is a glycoprotein secreted by testis, consisting of two disulfide-linked subunits, an alpha-subunit and a beta B-subunit. Serum inhibin B levels are significantly negatively correlated with the serum FSH levels in males, exerting a negative feedback on FSH secretion. In males the circulating levels of inhibin B increase shortly after birth and peak at 4-12 months of age, then decrease to low levels from 3-9 year. From the onset of puberty, the levels of inhibin B gradually increase. By pubertal stage II, the adult levels of inhibin B have been reached. At stage III of puberty, a negative correlation between inhibin B and FSH levels is present and persists from stage III of puberty onward. At 20-30 year of age, the levels of inhibin B reach another peak, then gradually decline with increasing age. The men with hypospermatogenesis and spermatogenesis arrest have significantly lower levels of inhibin B than those with normal spermatogenesis. The men with Sertoli-cell-only syndrome (SCO) have extremely low levels of inhibin B. There is a closely correlation between the presence of SCO and the level of serum inhibin B. A significantly positive correlation is also observed between testis volume and inhibin B level, as well as between sperm count and inhibin B level. The inhibin B is a direct product of the seminiferous tubules, reflecting the total testicular tissue. The measurable inhibin B production in adult requires the presence of germ cells. Inhibin B is regarded as a serum marker of spermatogenesis. The determination of serum inhibin B in males can be used to assess the spermatogenesis of infertile men, to diagnose the cryptorchidism and precocious puberty, to predict the outcome of testicular sperm extraction in men with non-obstructive azoospermia, and to evaluate the damage to spermatogenesis in men after radiotherapy or chemiotherapy.
Biomarkers ; blood ; Humans ; Inhibins ; blood ; Male ; Spermatogenesis ; physiology

OBJECTIVESTo investigate the possible differences in the inhibin B levels of seminal plasma and serum between fertile and infertile males and to obtain information on the relation between serum inhibin B or seminal plasma inhibin B and spermatogenesis.

METHODSSemen and blood samples were collected from fertile(n = 20), oligospermia(n = 20), asthenospermia(n = 22) and non-obstructive azoospermia(NOA) (n = 20) males at 8:00 am = 10:00 am. Semen parameters were analyzed. Levels of inhibin B in seminal plasma and serum, ACP, Fru, alpha-Glu in seminal plasma, serum levels of FSH, T, LH were determined.

RESULTSBoth levels of serum inhibin B and levels of seminal plasma inhibin B correlated significantly negatively with serum FSH(r = -0.536, P < 0.001 vs r = -0.288, P = 0.01), and statistically positively with sperm concentration(r = 0.49, P < 0.001 vs r = 0.48, P < 0.001). There was positive correlation between levels of seminal plasma inhibin B and activity of alpha-Glu in seminal plasma (r = 0.377, P = 0.001). The difference in levels of seminal plasma inhibin B was found only between fertile males or asthenospermia and NOA (P < 0.01 and P < 0.05, respectively). However, significant differences in levels of serum inhibin B were found not only between males with normal sperm concentration (including fertile males and asthenospermia) and NOA (P < 0.01), fertile males and oligospermia (P < 0.05), but also between oligospermia and NOA (P < 0.05). There was no correlation between serum inhibin B and seminal plasma inhibin B.

CONCLUSIONSBoth levels of serum inhibin B and seminal plasma inhibin B could reflect testis spermatogenesis status. Levels of seminal plasma inhibin B could also reflect the function of seminiferous duct, but the wide range of values limited its applicability.

Adult ; Humans ; Infertility, Male ; blood ; metabolism ; Inhibins ; analysis ; blood ; Male ; Semen ; chemistry ; Spermatogenesis

OBJECTIVETo investigate the relationship between pathological alterations of spermatogenic impairment in seminiferous tubules and serum inhibin B concentration in patients with azoospermia and to verify the significance of INH B in evaluating spermatogenesis.

METHODSEighty-three cases of azoospermia underwent testicular biopsy for the purpose of diagnosis. In accordance with the pathological alterations of spermatogenesis in seminiferous tubules, the samples were divided into four groups: Sertoli cell-only syndrome (n = 21); hypospermatogenesis (n = 20); maturation arrest (n = 24) and almost normal spermatogenesis (n = 18). Serum INHB and FSH, LH, T concentrations were tested before testicular biopsy for each patient respectively.

RESULTSThe INHB levels were (20. 85 +/- 18.78) pg/ml, (67.25 +/- 40.98) pg/ml, (73.63 +/- 25.54) pg/ml and (149.48 +/- 27.92) pg/ml in the above four groups, respectively. There was no significant statistical difference in the level of serum INH B between maturation arrest and hypospermatogenesis groups (P > 0.05), and there was a very significant difference in almost normal spermatogenesis group and the other three groups, respectively (P < 0.001). There was no significant difference in the concentration of serum FSH when maturation arrest group compared with spermatogenesis group (P > 0.05), whereas between the other two groups and between each of them and maturation arrest or almost normal spermatogenesis there was a very significant difference in the level of serum FSH (P < 0.05); The concentrations of LH and T were not significantly different among the four groups (P > 0.05).

CONCLUSIONSerum INHB concentration was decreased when spermatogenesis got impaired. It dropped the most markedly in Sertoli cell-only syndrome group. INH B reflects directly the spermatogenic function in seminiferous tubules of the testis. Therefore, it could be considered valuable for spermatogenesis and potential fertility in patients with azoospermia.

Adult ; Follicle Stimulating Hormone ; blood ; Humans ; Inhibins ; blood ; Luteinizing Hormone ; blood ; Male ; Oligospermia ; blood ; pathology ; Testis ; pathology ; Testosterone ; blood

BACKGROUNDIt is still controversial whether the serum inhibin B level is a superior predictor of the presence of sperm in testicular sperm extraction (TESE) in azoospermic men compared with serum follicle-stimulating hormone (FSH). In this study, we evaluated the diagnostic accuracy of serum inhibin B levels as a predictor of the outcome of TESE in Chinese non-obstructive azoospermic men and compared it with the traditional marker serum FSH and testicular volumes.

METHODSBasal values of serum hormone levels, testicular volumes and histological evaluation of 305 Chinese non-obstructive azoospermic men were analyzed. The level of inhibin B was measured using a three-step enzyme-linked immunoassay before sperm extraction, and the diagnostic accuracy of prediction of the outcome of TESE was compared for different markers by the receiver operating characteristics (ROC) curve analysis.

RESULTSTesticular sperm was successfully retrieved in 137 of 305 patients (44.9%). The serum level of inhibin B, the FSH and the testicular volume were significantly different between the successful TESE group and the unsuccessful group. According to the ROC curve analysis, for inhibin B, the cut-off value for discriminating between successful and failed TESE was 28.39 pg/ml (sensitivity 83.5%, specificity 79.1%). For FSH, the best cut-off value for discriminating was 11.05 pg/ml (sensitivity 83.5%, specificity 74.5%). The area under the ROC curve of serum inhibin B was similar to that of FSH. Combining the serum inhibin B with FSH levels did not improve the predictive value for successful TESE.

CONCLUSIONSSerum inhibin B and FSH levels are correlated with spermatogenesis. However, inhibin B is not superior to FSH in predicting the presence of sperm in TESE. And the combination of them does not improve the diagnostic accuracy on TESE outcome.

Adult ; Azoospermia ; blood ; Biomarkers ; blood ; Follicle Stimulating Hormone ; blood ; Humans ; Inhibins ; blood ; Male ; Sperm Retrieval ; Spermatogenesis ; physiology ; Testis ; cytology

Inhibin B, a glycoprotein produced predominantly by Sertoli cells and preferentially suppressing the production and secretion of follicle-stimulating hormone (FSH) in the pituitary, is closely related to spermatogenesis. Varicocele is the abnormal dilatation and tortuosity of the pampiniform plexus veins, which may contribute to spermatogenic dysfunction and male infertility. More and more evidence has shown that the level of serum inhibin B is negatively correlated with the severity of varicocele. Determination of the inhibin B level may help assess the severity of spermatogenic dysfunction of the patient and predict the outcomes of varicocele repair and therefore has a potential application value in the diagnosis and treatment of varicocele.
Follicle Stimulating Hormone ; metabolism ; Humans ; Infertility, Male ; blood ; etiology ; Inhibins ; blood ; Male ; Sertoli Cells ; Spermatogenesis ; Varicocele ; blood

The purpose of this study was to determine the diagnostic accuracy of serum inhibin B (INHB) as a predictor of the retrieval outcome of testicular haploid gametes (spermatids and testicular spermatozoa) in nonobstructive azoospermic men. Serum hormone levels, testicular volume, and histological evaluation were performed in 403 Chinese nonobstructive azoospermic men. Testicular haploid gamete was successfully retrieved in 213 of 403 patients (52.85%). The haploid gamete group always had higher INHB levels than the non-haploid gamete group. According to the receiver operating characteristic (ROC) curve analysis, INHB was a good predictor of testicular haploid gamete retrieval outcome in all patients (sensitivity: 77.93% and specificity: 91.58%) and patients with normal follicle-stimulating hormone (FSH; sensitivity: 88.52% and specificity: 70.83%). The area under the ROC curve (AUC) of INHB was similar to that of FSH in all patients or patients with normal FSH. In patients with elevated FSH, INHB was superior to FSH in predicting the presence of haploid gamete (AUC: 0.73 vs 0.55, P < 0.05), with a sensitivity of 60.00% and a specificity of 80.28%. It concluded that serum INHB as an effective marker for spermatogenesis was a significant predictor of testicular haploid gamete retrieval outcomes in nonobstructive azoospermic men. Especially, INHB is superior to FSH in predicting the presence of haploid gamete in the patients with elevated FSH.
Adult ; Azoospermia/blood* ; Follicle Stimulating Hormone/blood* ; Haploidy ; Humans ; Inhibins/blood* ; Male ; Sensitivity and Specificity ; Sperm Retrieval ; Spermatogenesis/physiology*

Inhibin B is a gonadal hormone that downregulates the pituitary production of follicle-stimulating hormone (FSH). In recent years, inhibin B has proved to be an excellent marker of spermatogenesis and even a predictive factor for the recovery of fertility in patients undergoing orchiectomy and antineoplastic treatments. We propose to study inhibin B levels in orchiectomised testicular cancer patients, in order to identify a minimum value representative of normal semen quality. This retrospective study evaluates hormonal and semen parameters of 290 normozoospermic patients attending the Laboratory of Seminology - Sperm Bank "Loredana Gandini" (Rome, Italy) for cryopreservation of seminal fluid following a diagnosis of testicular cancer (TC group) and 117 healthy, normozoospermic men as a control group (CTR group). The percentile distribution of gonadotropin and inhibin B values in the TC and CTR groups was analyzed. There was a statistically significant difference between the two groups in the levels of all hormones (P ≤ 0.001) and in all semen parameters (P < 0.05). About 20% of TC patients revealed inhibin B levels below the 5^th percentile of CTR group, despite normozoospermia, and 31.4% had normal spermatogenesis in the presence of FSH values >95^th percentile of CTR group. Orchiectomised patients for testicular cancer presented inhibin B levels lower than healthy patients, despite normozoospermia. Our study revealed the poor sensitivity of the current inhibin B reference range when applied to monorchidic patients, suggesting the need to establish more representative ranges to enable more appropriate counseling in relation to the patient's new endocrine condition.
Adult ; Gonadotropins/blood* ; Humans ; Inhibins/blood* ; Male ; Orchiectomy ; Reference Values ; Testicular Neoplasms/surgery* ; Testosterone/blood* ; Young Adult

ObjectiveTo investigate the role of the serum inhibin B (INHB) level in evaluating the testicular function of the prepubertal patient with varicocele (VC) after high ligation of the spermatic vein (HLSV).

METHODSThis study included 31 prepubertal male patients with left VC, averaging 12.55 years of age and 9 complicated by right VC. We collected peripheral blood samples before and at 4, 12 and 26 weeks after HLSV as well as spermatic venous blood samples intraoperatively for determination of the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), anti-sperm antibody (AsAb) and serum INHB by ELISA.

RESULTSCompared with the baseline, statistically significant differences were observed in the INHB level in the peripheral blood at 12 and 26 weeks after operation (［255.18 ± 69.97］ vs ［141.78 ± 59.82］ pg/ml, P < 0.05) and that in the spermatic venous blood intraoperatively (［255.18 ± 69.97］ vs ［412.44 ± 259.42］ pg/ml, P < 0.01). Spearman's analysis showed a negative correlation between the level of INHB and that of FSH (r = －0.224, P < 0.01).

CONCLUSIONSThe level of serum INHB in the peripheral blood of the prepubertal VC patient is decreased within 6 months after HLSV and negatively correlated with that of FSH. The levels of INHB and FSH may well reflect the testicular function of the prepubertal VC patient.

Adolescent ; Antibodies ; blood ; Biomarkers ; blood ; Child ; Follicle Stimulating Hormone ; blood ; Humans ; Inhibins ; blood ; Luteinizing Hormone ; blood ; Male ; Spermatozoa ; immunology ; Testosterone ; blood ; Varicocele ; blood

Objective: To investigate the influence of different procedures of testicular sperm retrieval on the levels of serum inhibin B (INHB), antisperm antibodies (AsAb), follicle-stimulating hormone (FSH), and testosterone (T) in patients with azoospermia. METHODS: We randomly assigned 210 azoospermia patients to receive testicular sperm extraction (TESE, n = 50), testicular sperm aspiration (TESA, n = 56), testicular fine needle aspiration (TEFNA, n = 64), or microscopic TESE (micro-TESE, n = 40). We measured the levels of serum INHB, FSH, and T and the positive rate of AsAb before and at 1 and 3 months after surgery. RESULTS: Compared with the baseline, the levels of serum FSH at 1 and 3 months after surgery showed no statistically significant differences in the TESE (［8.51 ± 4.34］ vs ［8.76 ± 3.07］ and ［7.24 ± 3.32］ IU/L, P >0.05), TESA (［7.70 ± 2.72］ vs ［7.90 ± 4.57］ and ［8.04 ± 3.65］ IU/L, P >0.05), TEFNA (［6.04 ± 3.17］ vs ［6.08 ± 2.70］ and ［6.10 ± 3.32］ IU/L, P >0.05), or micro-TESE group (［6.59 ± 2.74］ vs ［6.89 ± 1.78］ and ［6.75 ± 2.57］ IU/L, P >0.05); the positive rate of AsAb (IgM) was significantly increased at 1 month in the TESE (0.00 vs 14.00%, P <0.05) and micro-TESE groups (2.50% vs 15.00%, P <0.05), while the serum T level markedly decreased in the two groups (［16.52 ± 6.25］ vs ［9.25 ± 5.76］ nmol/L and ［14.16 ± 5.45］ vs ［8.23 ± 4.12］ nmol/L, P <0.05); the levels of serum INHB were remarkably reduced at 1 and 3 months in the TESE (［70.56 ± 23.17］ vs ［42.63 ± 15.34］ and ［44.05 ± 18.47］ pg/ml, P <0.05), TESA (［68.71 ± 14.74］ vs ［40.55 ± 20.51］ and ［42.11 ± 19.34］ pg/ml, P <0.05), TEFNA (［76.81 ± 27.04］ vs ［46.31 ± 19.28］ and ［48.32 ± 20.54］ pg/ml, P <0.05), and micro-TESE groups (［74.74 ± 28.35］ vs ［45.27 ± 18.83］ and ［47.64 ± 28.34］ pg/ml, P <0.05), but with no statistically significant differences among the four groups (P >0.05). CONCLUSIONS Different procedures of testicular sperm retrieval have different impacts on the testicular function and AsAb in patients with azoospermia.
Antibodies ; blood ; Azoospermia ; blood ; physiopathology ; Follicle Stimulating Hormone ; blood ; Humans ; Inhibins ; blood ; Male ; Sperm Retrieval ; Spermatozoa ; immunology ; Testis ; metabolism ; physiopathology ; Testosterone ; blood

Men with non-obstructive azoospermia (NOA) can achieve fertility by testicular sperm extraction (TESE) coupled with intracytoplasmic sperm injection (ICSI), the key to which is the successful retrieval of sperm from the testis. Although improved testicular sperm extraction techniques have increased the chances of sperm retrieval, to predict preoperatively the success of sperm retrieval from NOA patients remains challenging. A non-invasive diagnostic technique predicting the presence of sperm in the testis would be useful for avoiding possible surgical intervention. At present, some preoperative variables, such as serum FSH, inhibin B level, testis volume, genetic analysis, histopathology on diagnostic biopsy, Raman Spectroscopy, and molecular and protein markers, have provided new insights into the chances of successful sperm retrieval in NOA males. This review aims to evaluate the preoperative factors currently available for predicting the outcomes of sperm retrieval from NOA patients.
Azoospermia ; therapy ; Biomarkers ; Biopsy ; Genetic Testing ; Humans ; Inhibins ; blood ; Male ; Sperm Injections, Intracytoplasmic ; Sperm Retrieval ; Spermatozoa ; cytology ; Testis ; cytology