Subclinical hypercortisolism among polycythemia vera patients.
BACKGROUND
JAK2V617F, a somatic gain-of-function mutation involving the JAK2 tyrosine kinase gene, occurs in nearly all patients with polycythemia vera (PV). JAK2 is also essential in hypothalamo-pituitary-adrenal (HPA) axis system which is known to play a role in subsequent steroid secretion. The purpose of this study was to determine whether or not PV induces subclinical hypercortisolism (SH).


METHODS
Cross-sectional study. In order to compare the prevalence of SH in PV and matched control individuals, we performed a case-controlled study, enrolling 31 PV and 20 age- and body mass index-matched patients.


RESULTS
Adrenal endocrine function was assessed in a cohort of 31 patients with PV. Baseline serum cortisol levels and 2-day 2 mg DST (dexamethasone suppression test, 0.5 mg dexamethasone orally every 6 hours for two days) showed a trend for higher serum cortisol levels in PV patients than in control subjects. Among the 31 patients, 6 had biological abnormality of the hypothalamic-pituitary-adrenal axis and were diagnosed as subclinical hypercortisolism. None of the subjects in the control group exhibited cortisol responses to DST higher than 50 nmol/L.


CONCLUSIONS
In conclusion, a relatively high prevalence of hypercortisolism was found in PV patients. As these observations were in a small cohort of PV, further studies are needed to evaluate HPA axis in PV patients.
Bilgir
Oktay
O
Department of Internal Medicine, Division of Hematology, Izmir Bozyaka Training and Research Hospital, Izmir, Turkey.
Kebapcilar
Levent
L
Alacacioglu
Inci
I
Bilgir
Ferda
F
Yildiz
Yasar
Y
Yuksel
Arif
A
Sari
Ismail
I
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003480:Cushing Syndrome / Q000097:blood / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D011087:Polycythemia Vera / Q000150:complications*; D015995:Prevalence; D012307:Risk Factors; D014421:Turkey
D006854:Hydrocortisone