Vitamin D metabolite-mediated hypercalcemia with suppressed parathormone concentration in Pneumocystis jiroveci pneumonia after kidney transplantation.
Pneumocystis jiroveci pneumonia (PJP) is a severe complication in immunocompromised hosts including transplant recipients. Hypercalcemia (HCa) is not a classic symptom of the disease. However, HCa (mean [SD; range], 2.90 [0.20; 2.71-3.17] mmol/L) was detected in 5 patients with PJP at diagnosis. The HCa was associated with decreased concentrations of circulating parathormone (PTH), from 294 (292) ng/L 3 to 6 months previously to 20 (23.5; 7-53) ng/L. Concentrations of 1,25-(OH)2 vitamin D, measured in 3 patients, were in the high normal range (54.66 [7.23; 225-66] microg/L), whereas 25-(OH) vitamin D concentrations were low (13.9 [2.17; 20-60] microg/L). After treatment with trimethoprim-sulfamethoxazole for 21 days, 4 patients recovered and 1 died. Calcium and PTH concentrations rapidly returned to normal (2.36 [0.05] mmol/L and 89 [29.7] ng/L, respectively) at 2 months after the acute phase of the disease. Although fewer than 10 cases of PJP-associated HCa have been reported to date, it is possible that this association is more frequent than previously thought because our cases were detected during 2 years. As in other granulomatous disease-induced HCa, including fungal infections, it is likely that endogenous extrarenal production of 1-alpha-hydroxylase by activated macrophages and by interferon-gamma involved in granuloma formation results in increased conversion from 25-(OH) vitamin D to 1,25-(OH)2 vitamin D and, consequently, in transient HCa and suppression of PTH secretion. Fortuitous detection of HCa in transplant recipients with pulmonary symptoms must raise suspicion of PJP or fungal infection.
Department of Nephrology-Transplantation, Centre Hospitalier Universitaire, Dijon, France.
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Hajji
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Dalle
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Harzallah
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Tanter
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Rifle
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Mousson
D000328:Adult; D000368:Aged; D003404:Creatinine / Q000378:metabolism; D004100:Dihydroxycholecalciferols / Q000097:blood; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000453:epidemiology*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000172:deficiency*; D045363:Pneumocystis carinii; D011020:Pneumonia, Pneumocystis / Q000097:blood / Q000453:epidemiology*; D014807:Vitamin D / Q000627:therapeutic use*
D004100:Dihydroxycholecalciferols; D010281:Parathyroid Hormone; D014807:Vitamin D; D003404:Creatinine