Causes of Hypercalcemia in People Living with HIV in the HAART Era

Background: Hypercalcemia is an uncommon finding in people living with HIV (PLHIV). Causes of hypercalcemia in PLHIV have not been well documented. As such, we studied the causes of hypercalcemia in PLHIV.

Methods: We conducted a retrospective review of PLHIV who had corrected serum calcium of ≥10.5 mg/dL between 2010 and 2019. Demographic data, associated diseases, and treatment details were collected. Corrected serum calcium levels were compared among the causes of hypercalcemia.

Results: A total of 70 of 2168 (3.2%) PLHIV had hypercalcemia. Forty-nine (70.0%) were male with a mean age of 47.7 ± 4.7 years. Only two (2.9%) had symptoms of hypercalcemia. Fifty-four patients had identifiable causes of hypercalcemia; 21 infections (30.0%), 17 solid organ malignancies (24.3%), 14 hematologic malignancies (20.0%), and two other specific causes (2.9%). Mean corrected serum calcium concentrations of PLHIV who had solid organ malignancy, hematologic malignancy, infection, and unknown causes were 12.8 ± 2.1, 11.4 ± 1.0, 11.2 ± 0.6, and 10.8 ± 0.2 mg/dL, respectively. Corrected serum calcium levels were significantly greater in patients who had solid organ malignancy comparing to those with other causes of hypercalcemia ( < 0.05, all). Logistic regression identified solid organ malignancy as the only factor associated with moderate to severe hypercalcemia (odds ratio 12.72, 95% confidence interval 3.11-52.08;  < 0.001).

Conclusions: Hypercalcemia in PLHIV is associated with solid organ malignancy, hematologic malignancy, and infection. Most PLHIV with hypercalcemia are asymptomatic. Solid organ malignancy is associated with moderate to severe hypercalcemia, and as such PLHIV presenting with moderate to severe hypercalcemia should be investigated for solid organ malignancy.