We agree entirely with Dr. Banerjee that multitransfused patients of
beta thalassemia are susceptible to multiple endocrine dysfunctions of
clinical import and hence need comprehensive evaluation. Cost
considerations largely dictate the extent of evaluation especially in a
country like ours. Regarding serum ACTH levels for diagnosis of
secondary adrenal insufficiency, we beg to differ from Dr. Banerjee. A
large overlap of ACTH levels, between normal and proven secondary
adrenal insufficiency, has been documented in literature(1) and hence
the test has limited value. The more discriminant CRH stimulation test
is not routinely used in clinical practice because of cost and
non-availability. We concur with the views on pituitary MR imaging as an
index of iron overload. In addition to T2 relaxation rate, the pituitary
to fat signal intensity ratio (P/F) has been used as another marker of
iron overload. The degree of reduction of P/F ratio correlates well with
presence of hypogonadotropic hypogonadism, with a sensitivity of 90%,
specificity of 89% and an overall accuracy of 89%(2).
R.K. Marwaha,
Division of Hematology and Oncology,
Advanced Pediatric Center, PGIMER,
Chandigarh 160 012, India.
