Drug induced phospholipidosis following haematopoietic stem cell transplantation complicated by graft versus host disease: a small case series

Drug-induced phospholipidosis is a rare histopathological phenomenon associated with an abnormal intracellular accumulation of polar phospholipids, resulting from the use of cationic amphiphilic drugs. We describe two patients who developed acute kidney injury (AKI) likely secondary to phospholipidosis attributed to azithromycin and posaconazole, following haematopoietic stem cell transplantation (HSCT) complicated by steroid-refractory graft versus host disease (GVHD). Both patients were male and had been referred for assessment of renal impairment, which differed in the rate of decline. Each patient had microalbuminuria and absence of microscopic haematuria while immune serology, complement and paraprotein studies were unremarkable. Kidney biopsy demonstrated foamy cells in the tubular epithelium and mesangium on light microscopy, with lipid-like vesicles in the mesangium, glomerular endothelium and tubular epithelium on electron microscopy. Azithromycin and posaconazole were ceased as cationic amphiphilic medications likely to have caused phospholipidosis, with partial recovery of kidney function over 6 months. Our case report is the first to link these medications, commonly used in steroid-refractory GVHD following HSCT, to a clinically significant, reversible AKI due to phospholipidosis. This highlights a rare but important diagnostic consideration for nephrologists and transplant physicians.