Two Cases of Symptomatic Familial Hypocalciuric Hypercalcemia: Treatment Response to Calcimimetic Therapy.

Familial hypocalciuric hypercalcemia (FHH) is marked by mild to moderate hypercalcemia, normal-elevated serum PTH levels, and relative hypocalciuria. Cinacalcet, a calcimimetic therapy, has been reported to reduce symptom burden and serum calcium levels in FHH. We report 2 adult males with chronic hypercalcemia, with initial concerns for primary hyperparathyroidism. Urine calcium screening and genetic testing confirmed FHH in both patients. Shortened QTc normalized while on cinacalcet in the first patient and reductions in serum calcium and PTH levels without symptomatic hypercalcemia were noted in the second patient. Calcimimetic therapy can potentially be offered to FHH patients, particularly those with hypercalcemia symptoms, serum calcium levels >1 mg/dL (0.25 mmol/L) above normal or at risk of cardiac arrhythmias. Cinacalcet treatment was overall well tolerated and significantly reduced serum calcium and PTH levels in 2 adult FHH patients over time. Calcimimetic therapy has shown promise in managing persistent hypercalcemia and potential adverse events in FHH patients. Potential barriers include indefinite treatment, cost, and possible adverse effects.

Pellagra Post-Roux-en-Y Gastric Bypass Surgery.

Background/Objective: Micronutrient deficiencies such as pellagra are rarely seen after bariatric surgery and can be challenging to diagnose and manage. Alcohol use can precipitate nutritional deficiencies. Case Report: A 51-year-old woman with a history of Roux-en-Y gastric bypass surgery who later developed an alcohol-use disorder after her diagnosis of breast cancer. She experienced a subacute decline in her physical and cognitive function along with a rash after radiation treatment for breast cancer, lower extremity pain and weakness, anemia, and diarrhea with severe hypokalemia. Workup showed undetectable niacin levels. She initially did not respond to an oral niacin replacement, necessitating intramuscular injections. Alcohol cessation and parenteral B complex replacement led to the resolution of her symptoms and biochemical derangements. Discussion: Bariatric surgery with concomitant alcohol use can precipitate niacin deficiency-induced liver dysfunction. In the correct clinical setting, screening for alcohol use and checking niacin levels may help avoid extensive testing and can help make the correct diagnosis. Parenteral replacement may be necessary in this setting. Conclusion: Niacin deficiency needs to be considered in patients with bariatric surgery with a history of alcoholism in the correct clinical setting.

Acute Immune Thrombocytopenia (ITP) Following COVID-19 Vaccination in a Patient With Previously Stable ITP.

Immune thrombocytopenia (ITP) is an autoimmune condition associated with multiple risk factors including viral infections (hepatitis B virus/hepatitis C virus/cytomegalovirus, HIV, and recently severe acute respiratory syndrome coronavirus 2) and vaccines. Though immune mechanisms have been proposed to explain the pathogenesis of acute ITP, autoimmunity with the coronavirus disease 2019 (COVID-19) vaccine is still unclear and needs further research. We report a case of acute ITP after administration of the Pfizer-BioNTech mRNA COVID-19 vaccine in a patient with previously stable ITP.