First case report of pre-mortem biopsy-proven kidney involvement by necrobiotic xanthogranuloma with monoclonal gammopathy.

Necrobiotic xanthogranuloma (NXG) is a rare non-Langerhans cell histiocytosis with characteristic cutaneous features and rare visceral involvement. More than 80% of individuals with this disease have a detectable paraprotein but the precise pathogenesis remains obscure. A 68-year-old man with known cutaneous necrobiotic xanthogranuloma presented with acute kidney injury and imaging suggestive of bilateral perinephric infiltration. Renal biopsy showed a prominent histiocytic infiltration of renal capsule and cortex with necrobiosis and characteristic 'Touton-type' giant cells suggestive of necrobiotic xanthogranuloma involvement. Kidney function returned to normal and cutaneous lesions improved with a combination of corticosteroid, chlorambucil and rituximab. This case represents only the second reported incidence of kidney involvement by necrobiotic xanthogranuloma and the first with acute kidney injury and pre-mortem histopathology. This report adds to a small body of literature on the diagnosis and management of visceral involvement by this rare disease.

Body mass index and noninfectious comorbidity in HIV-positive patients commencing antiretroviral therapy in Zimbabwe.

OBJECTIVES: The aim of the study was to describe the prevalence of elevated body mass index (BMI) in a cohort of treatment-naïve people living with HIV (PLWH) and to investigate the association of BMI with CD4 count and noninfectious comorbidities including hypertension and renal impairment. METHODS: A retrospective cohort study of 1598 PLWH at the Newlands Clinic in Harare, Zimbabwe was carried out. Data were extracted from the medical records at baseline and 6 months after initiation of treatment. The univariate association between BMI and CD4 count was assessed and multiple regression models were used to predict factors associated with loss of renal function and change in CD4 count at 6 months. RESULTS: Overweight and obesity (BMI ≥ 25 kg/m2 ) were prevalent in this cohort (34%), as was the presence of hypertension (18%). Higher BMI was associated with a higher CD4 count at baseline and 6 months (B = 0.28 and 0.24, respectively; P < 0.001 for both), adjusted for age and sex. The presence of hypertension independently predicted loss of renal function at 6 months (B = -15.31; P < 0.001), adjusted for BMI, CD4 count and sex. High BMI itself was also independently associated with a decline in renal function (B = -0.41; P = 0.003), adjusted for other significant variables. CONCLUSIONS: We demonstrate a high prevalence of overweight/obesity and hypertension in an urban cohort of PLWH in Zimbabwe. Higher BMI was associated with a higher CD4 count, both before and 6 months after commencing antiretroviral therapy; it was also associated with loss of renal function in this cohort.