# Hypercalcemia as a rare manifestation of immune reconstitution inflammatory syndrome (IRIS) in a person living with Human Immunodeficiency Virus (HIV) with disseminated nontuberculous mycobacteriosis

## TL;DR

A rare case of hypercalcemia caused by immune reconstitution inflammatory syndrome in an HIV patient with a mycobacterial infection is reported.

## Contribution

This case report highlights hypercalcemia as a rare manifestation of IRIS in HIV patients with disseminated mycobacteriosis.

## Key findings

- Hypercalcemia and acute kidney damage occurred in an HIV patient with M. avium infection despite ART and antimycobacterial treatment.
- Granulomatous inflammation consistent with IRIS was confirmed via biopsy of lymph nodes and the duodenum.
- Treatment with diuresis, bisphosphonates, and calcitonin normalized calcium levels and restored kidney function.

## Abstract

Granulomatosis due to immune reconstitution inflammatory syndrome (IRIS) and disseminated Mycobacterium avium-intracellulare (M. avium) infection may trigger hypercalcemia. Here, we report a rare case of hypercalcemia and acute kidney damage related to IRIS in a person living with Human Immunodeficiency Virus (HIV).

A 39-year-old male person living with HIV presented with muscle weakness and unwanted weight loss of 8 kg within the last 2 weeks. Laboratory findings included serum hypercalcemia of 3.27 mmol/mL associated with elevated calcitriol and acute kidney damage. Since the first diagnosis of HIV and concomitant disseminated M. avium infection, the patient received antiretroviral therapy (ART), rifabutin, clarithromycin, and ethambutol. 18Fluoro-D-glucose positron emission computed tomography (18FDG-PET/CT) showed progressive multilocular lymphadenopathy. Biopsy specimen from the duodenum as well as retroperitoneal and mediastinal lymph nodes revealed granulomatous inflammation consistent with IRIS. Treatment with forced diuresis, bisphosphonates, and calcitonin normalized serum calcium and kidney function recovered.

Hypercalcemia due to IRIS is a rare differential diagnosis in persons living with HIV and may lead to acute kidney damage, despite sufficient ART and antimycobacterial treatment.