HIV-related Disseminated Visceral Kaposi Sarcoma With Normal CD4 Count

Abstract Introduction Kaposi Sarcoma (KS) is an Acquired Immune Deficiency Syndrome (AIDS)-defining illness caused by Human Herpesvirus 8 (HHV-8), characterized by mesenchymal tumors comprising malignant spindle cells of lymphatic endothelial origin. It presents in four epidemiological forms: classic (sporadic), endemic, iatrogenic, and AIDS-related (epidemic). These tumors are associated with vascular proliferation, extravasated blood, inflammation, and fibrosis. They typically manifest as skin lesions but may also affect the gastrointestinal and respiratory tracts. AIDS-related Kaposi Sarcoma is most typically associated with low CD4 count (CD4 < 200 cell/mm3). We present a case of disseminated visceral KS despite a CD4 count >400 cell/mm3 in an HIV patient. Description A 42-year-old man presented with dyspnea for 2 weeks. He was diagnosed with HIV infection in 2008 and took anti-retroviral therapy (ART) till 2017. His chest imaging showed bilateral interstitial and nodular infiltrates with mediastinal lymphadenopathy. Examination revealed a friable pedunculated mass on the base of tongue, diffuse purple maculopapular lesions on chest, abdomen, groin, and bilateral lower extremities. His CD4 count was 429 cell/mm3 and HIV viral load was 370,000 copies/ml. Prior CD 4 counts were > 400 cell/ mm3 as well. Skin biopsy confirmed Kaposi Sarcoma. Bronchoscopy with bronchoalveolar lavage and lung biopsy was performed. BAL was negative for bacterial, fungal, mycobacterial organisms including Pneumocystis jirovecci. Lung mucosal biopsy confirmed KS in the bronchial tree as well. (Fig. 1) He had worsening hypoxemic respiratory failure over the next week, requiring intubation. Despite aggressive measures including prone positioning, inhaled epoprostenol and neuromuscular paralysis, he passed away from refractory hypoxemia. Discussion Our patient's unusual presentation of biopsy-confirmed visceral disseminated KS with a normal CD4 count, and an elevated HIV viral load, highlights complex pathophysiology potentially related to immune tolerance. The upregulation of PD-L1 transcription by HHV-8 infection in primary monocytes may contribute to this immune tolerance, which could subsequently lead to disseminated KS, despite a normal CD4 count, so clinical index of suspicion should be high. Additionally, HIV viral load may have a stronger association than CD4 count with onset of AIDS and KS. However, a larger sample size is needed to establish the association.