The Cytokine Storm Within

A 38-year-old man with HIV infection diagnosed three years ago presents with six weeks of drenching night sweats, progressive fatigue, and a 20-pound weight loss. His antiretroviral therapy consists of bictegravir, emtricitabine, and tenofovir alafenamide, and his most recent HIV viral load was less than 20 copies/mL three months ago. His CD4 count at that time was 185 cells/μL. He denies cough, dysuria, diarrhea, or new skin lesions. He has no recent travel, sick contacts, or known tuberculosis exposure.

On examination he appears chronically ill and fatigued. Temperature is 38.2°C, heart rate 104 bpm, blood pressure 112/68 mmHg. Bilateral cervical, axillary, and inguinal lymph nodes are enlarged, firm, non-tender, and mobile, ranging from 1.5 to 3 cm. The spleen is palpable 4 cm below the left costal margin. No skin lesions, oral ulcers, or petechiae are present. The remainder of the examination is unremarkable.

Laboratory studies reveal hemoglobin 9.2 g/dL (MCV 86), white blood cell count 6,800/μL with a normal differential, platelet count 135,000/μL, albumin 2.4 g/dL, CRP 128 mg/L, and ESR 95 mm/hr. Creatinine, liver enzymes, and lactate dehydrogenase are within normal limits. Thick and thin blood smears are negative. Serum cryptococcal antigen is negative. Quantiferon-TB Gold is negative. Blood cultures show no growth at five days.

CT of the chest, abdomen, and pelvis demonstrates diffusely enlarged mediastinal, retroperitoneal, and mesenteric lymph nodes with a dominant 8.5 cm intensely enhancing retroperitoneal mass containing scattered calcifications. The spleen is enlarged at 16 cm. No pulmonary infiltrates or hepatic lesions are seen. An excisional biopsy of a right cervical lymph node is performed. Pathology reveals Castleman disease histology with expanded mantles, penetrating hyalinized vessels, and scattered plasmablasts in the interfollicular regions.