Comparison between serum holotranscobalamin and total vitamin B12 as indicators of Vitamin B12 status

This study aims to assess the usefulness of serum holotranscobalamin [holo TC], the fraction of vitamin B12 that is available for tissue uptake, compared with total vitamin B12 in patients investigated for vitamin B12 disorders. Serum samples were randomly selected from 76 patients [48females, 28 males; age range 12-69 years] referred to the Clinical Biochemistry Laboratory, Royal Hospital for the assessment of vitamin B12 status. For each patient, serum total vitamin B12 was determined by chemiluminescent microparticle immunoassay on Architect 2000 analyzer and holo TC[active vitamin B12] level was determined by microparticle enzyme immunoassay on Axsym analyzer [both from Abbott, USA]. Comparison of the data was conducted to reflect the mean, standard deviation [SD] and correlation coefficient between the two groups. The mean [SD] for serum holo TC and total vitamin B12 were 46.5[32.2] pmol/L and 316.3[165.6] pmol/L respectively. There was a significant correlation between holo TC and total vitamin B12 [r=0.765, P<0.001] and the regression equation was expressed as; y= a+bx [i.e: holot TC = 1.5+0.14 total vitamin B12]. Also, the results were assessed for any misclassification when comparing holo TC and the total vitamin B12 in terms of whether each or both values agree or disagree for classifying the patients as having normal or abnormal [low or high] results, based on the cut-off thresholds of the kit's quoted reference range for holo TC of 9-123 pmol/L and for total vitamin B12 of 140-600 pmol/L. Accordingly, in69 [90.8%] samples, there was a parallel agreement/ classification of results, both being normal or abnormal. In 61 [80.4%] patients, both results were normal, whereas in 4 [5.2%] patients, both results were high, and in 4 [5.2%] patients both results were low. However, in 7[9.8%] cases, there was disagreement/ misclassification of results; 6 [7.8%] patients, holo TC was normal while total vitamin B12 was low, and in 1 [1.4%] patient, holo TC was normal while total vitamin B12 was low, and in 1 [1.4%] patient, holo TC was normal while total vitamin B 12 was high. It can be recommended that holo TC and total vitamin B 12, alone and in combination, have almost equal diagnostic efficiency reflector of vitamin B 12 status. Further comparison studies based on a gold standard method for classifying vitamin B 12 status are worth considering

Prevalence of endocrinopathies in patients with beta-thalassaemia major: a cross-sectional study in Oman

Beta-thalassaemia major is a common medical problem worldwide. There is little data dealing with the nature prevalence of different endocrine disorders in this disease in Sultanate of Oman. To establish the prevalence and times of occurrence of endocrine disorders in patients with beta-thalassaemia major. This cross-sectional study was conducted during Jan-Jul 2008 and dealt with 30 Omani patients with transfusion-dependent homozygous beta-thalassaemia major who were consulting Thalassaemia Clinic, Royal Hospital. They included 15 males and 15 females, aged 16 to 32 years with median of 21 years and mean +/- SD of 21.23 +/- 3.42 years. The medical records of these patients were reviewed and their endocrine functions were assessed. This assessment included pituitary and gonadal function, thyroid function, bone profile [including Parathyroid Hormone], morning cortisol and fasting glucose. These profiles were reviewed to exclude hypogonadism, hypothyroidism, hypoparathyroidism, hypoadrenalism or diabetes mellitus. Hypogonadism was reported in 22 [73.3%] patients [13 Female, 9 male]. Low levels of Follicle-Stimulating Hormone [FSH] and low Luteinizing Hormone [LH] with low estradiol [in females] or testosterone [in males] was noted in 15 [50.0%] patients [7 female, 8 male]. Normal [but inappropriately low] levels of FSH and LH with low estradiol [in females] or testosterone [in males] was noted in 7 [23.3%] patients [6 female, 1 male]. Primary hypothyroidism was present in only 1 [3.3%] patient [female] who Hypoparathyroidism was found in 3 [10.0%] patients [2 female, 1 male]. Diabetes mellitus with high fasting glucose was noted in 8 [26.7%] patients [2 female, 6 male]. Morning cortisol levels for all patients were within the reference range with no suspicion of hypoadrenal cortical function. Eight [26.7%] patients had no endocrine disorder, 12 [40.0%] patients had one disorder, 8 [26.7%] patients had 2 disorders, and 2[6.7%] patients had 3 endocrine disorders. There was no significant difference [p>0.050] in mean serum ferritin in thalassaemics with or without endocrinopathy, regardless of the number of endocrinopathy. There is high prevalence of endocrine disorders among Omani beta-thalassaemic adult patients. This signifies the importance of awareness for their development and monitoring for early detection and replacement therapy. No relationship between serum ferritin and development of endocrinopathy was noted