ODP122 Recurrent Episodes of Hypercalcemia due to Disseminated Mycobacterium Avium Complex Infection-related Immune Reconstitution Inflammatory Syndrome

Abstract

Abstract Introduction Immune reconstitution inflammatory syndrome (IRIS) may occur in patients with acquired immunodeficiency syndrome (AIDS) following initiation of antiretroviral therapy (ART) due to exacerbation of preexisting infectious process, such as disseminated mycobacterium avium complex (dMAC). This type of inflammatory process may be associated with granuloma formation and 1,25(OH) 2 vitamin D-mediated hypercalcemia. Hypercalcemia typically is controlled with a single dose of intravenous bisphosphonate or a two to four-week course of glucocorticoid, in addition to antibiotics for dMAC and ART. Here we present a case of IRIS-associated hypercalcemia related to dMAC resistant to intravenous bisphosphonate therapy and an extended glucocorticoid course. Case presentation A 30-year-old man with AIDS with CD4 count 4 cells/mm^3 (441-2,156) was admitted with subacute fevers, chills, and cough one month after starting ART. Cultures drawn during admission were positive for MAC and he was started on therapy for dMAC with ethambutol and azithromycin. Seven months after starting ART, he was readmitted with weakness and fatigue and found to have calcium 13.5 mg/dL (8.6-10.4), albumin 3.9 g/dL (3.9-5. 0), creatinine 1.40 mg/dL (0.6-1.3), CD4 count 80 cells/mm3. Further workup revealed intact PTH 2 pg/mL (11-51), 25-OH vitamin D 38 ng/mL (20-50), 1,25(OH) 2 vitamin D 171 pg/mL (19.9-79.3), PTHrP < 2. 0 pmol/L (0. 0-2.3), suggestive of PTH-independent hypercalcemia mediated by 1,25(OH) 2 vitamin D. CT scan of the chest showed multiple cavitary lesions, ground glass nodularity, and diffuse lymphadenopathy. He was treated with intravenous fluids, zoledronic acid 4mg, and continued ART and antibiotics for MAC. On discharge calcium was 9.5 mg/dL. He had recurrence of 1,25(OH) 2 vitamin D-mediated hypercalcemia (calcium 13.6mg/dL) 11 months after starting ART, which was controlled with intravenous fluid and prednisone 60mg tapered over 6 weeks. He then had recurrence of hypercalcemia 13 and 16 months after starting ART, each resolved with intravenous fluids and repeat prolonged prednisone courses. Testing for other infectious causes of granulomatous disease including Cryptococcus, Histoplasma, Mycoplasma tuberculosis was negative during multiple presentations. At 13 months, his CD4 count was 214 cells/mm^3 and repeat CT scan of the chest showed improvement in size of cavitary nodule and ground glass nodularity. Conclusion IRIS related to dMAC is an uncommon cause of 1,25(OH)2 vitamin D-mediated hypercalcemia. Multiple recurrences of hypercalcemia and the need for extended courses of glucocorticoid despite improvement of underlying infectious process has not previously been reported. Presentation: No date and time listed