Reference Ranges of Serum Anti-Müllerian Hormone in Healthy Reproductive-aged Omani Women

Objectives: Anti-Müllerian hormone (AMH), a glycoprotein that belongs to the transforming growth factor-beta superfamily, is important for women’s health. We aimed to determine the age-specific reference range of serum AMH in healthy Omani women from reproductive ages to menopause. Methods: This cross-sectional cohort study was conducted among a group of healthy 20–50 years old Omani women. The participants were required to have body mass index < 32 kg/m2 regular periods, no history of chronic illness, polycystic ovary syndrome, or gynecological operation. They were also required to not be using any hormonal contraceptive. Serum concentrations of AMH, follicle-stimulating hormone, luteinizing hormone, progesterone, and hemoglobin A1c were measured. AMH-age nomogram and AMH levels were compared between the six selected age groups. Results: The subjects were 319 Omani women aged 20–50 years. Serum AMH concentrations were found to decrease progressively with increasing age. An exponential model defined as √AMH = 479.02 × 0.91age was selected to explain the reduction in AMH with age (R2 = 0.298). The median AMH levels were 26.61 pmol/L for those aged 20–25 years, 20.89 pmol/L for 26–30 years, 19.92 pmol/L for 31–35 years, 13.71 pmol/L for 36–40 years, 9.24 pmol/L for 41–45 years, and 0.68 pmol/L for 46–50 years. The recommended 2.5thto 97.5thpercentiles of AMH level, as reference ranges for various age groups, were found to be: 10.63–55.64 pmol/L (20–25 years), 3.74–61.88 pmol/L (26–30 years), 5.49–47.56 pmol/L (31–35 years), 2.15–48.91 pmol/L (36–40 years), 0.92–41.26 pmol/L (41–45 years), and 0.14–5.10 pmol/L (46–50 years).Conclusions: This study (the first in Oman) determined the age-specific reference ranges of serum AMH in healthy Omani women in the age range of 20–50 years

Chromogranin A as a Biochemical Marker for Neuroendocrine Tumors: A Single Center Experience at Royal Hospital, Oman

Objectives: To evaluate the significance of serum chromogranin A (CgA) status in patients with and without different neuroendocrine tumors (NETs) by conducting a retrospective assessment of the diagnostic utility and limitations of CgA as a biomarker for NETs in a tertiary care hospital in Oman. Methods: We conducted a retrospective analysis of CgA requests referred to the Clinical Biochemistry Laboratory, Royal Hospital, Oman over a 24-month period (April 2012 to March 2014). During this time, 302 CgA tests for 270 patients (119 males and 151 females; age range 11–86 years and mean±standard deviation (SD) 44.0±18.0 years), were requested. Of these CgA tests, 245 tests were performed for 245 patients investigated for the diagnosis of NETs, and 57 CgA tests were performed for 25 patients with diagnosed NETs who were undergoing follow-up. Serum CgA levels were analyzed using the enzyme-linked immunosorbent assay based on a cut-off value of 22 IU/L. Results: Of the 302 CgA tests reviewed, 197 (65.2%) were within the quoted normal range; however, 105 (34.8%) had CgA > 22 IU/L. Of the 245 patients with first-line CgA, 38 patients (15.5%) had NET that included carcinoid, pheochromocytoma, pancreatic NET, adrenal adenoma, prostatic adenocarcinoma, gastrointestinal NET, medullary thyroid carcinoma, Schwannoma, lung small cell carcinoma, parathyroid adenoma, and pituitary macroadenoma. The mean±SD of CgA in these patients with NETs was 205.0±172.0 IU/L. Meanwhile, there were 45 (18.3%) patients with CgA > 22 IU/L (83.0±116.0 IU/L) who did not have NETs. The conditions/diseases included: essential hypertension, chronic kidney disease, heart failure, peptic ulcer, chronic diarrhea, use of proton pump inhibitors, and other chronic diseases (hypothyroidism, asthma, diabetes mellitus). Of the 25 patients with known NET who were followed-up, there were 57 CgA results (29 with CgA ≤ 22 IU/L and 28 with CgA > 22 IU/L). The overall clinical sensitivity of CgA in the diagnosis of NETs was 84.2%, overall specificity was 78.2%, positive predictive value was 41.5%, negative predictive value was 96.4%, and overall efficiency was 79.2%. In patients with individual NET, a good reflection in CgA was noticed in the follow-up period following surgery or therapy. Conclusions: Serum CgA is a sensitive and effective noninvasive laboratory test for the clinical detection and management of NETs. Awareness of the pitfalls of the tests in patients with non-NET conditions, particularly chronic diseases and use of certain drugs, is important to be considered during the interpretation of the CgA levels