A peculiar case of persistent CPK elevation in a person diagnosed with acute HIV: what is behind?

Introduction: The coexistence of common and rare conditions in a single person may represent a diagnostic challenge. We herein report the case of a young gentleman diagnosed with an acute HIV infection who had a history of myalgias and exercise intolerance and experienced elevated creatinine and phosphokinase enzyme levels.

Clinical presentation: A 24-year-old gentleman was diagnosed with an acute HIV in May 2023 (HIV-RNA > 10.000.000 copies/ml, CD4+ count 417 cell/L) and started same-day combinarion antiretroviral therapy, cART, with darunavir/cobicistat/tenofovir alafenamide/emtricitabine+dolutegravir), switching to dolutegravir/lamivudine once undetectable, 6 weeks after. After 5 months, he was hospitalized with fever, headache, and acute renal failure (creatinine 500 umol/L). Later, CPK peaked at >22,000 mg/dl. He denied chemsex/drug use and had recently started exercising on a regular basis. HIV-RNA was undetectable, cerebrospinal fluid (CSF) examination was unremarkable. cART was temporarily stopped with the normalization of labs. After 20 days, cART was restarted, as well as physical activity, with relapse of the symptoms requiring rehospitalization. Workups for autoimmune and infectious causes were negative. Suspecting drug-related myositis (data on myopathies under integrase inhibitors have been reported), muscle MRI, muscle biopsy, genetic analyses, hair analysis were performed. He tested positive for cocaine and amphetamines. Muscle biopsy showed type 1 fiber atrophy while muscle magnetic resonance imaging was unremarkable. In January 2025, genetic testing came back confirming type VII glycogenosis.

Discussion: This case highlights the diagnostic complexity of rare metabolic disorders, especially when coexisting with acute HIV, continuous medication use and drug exposure. It allows us to highlight the importance of considering rare metabolic disorders as differential diagnoses, as they can mimic systemic illnesses or drug-related effects.