PRESENTATION AND DIAGNOSIS

In the early years of the AIDS epidemic, before anti retroviral therapy, the classic clinical presentation o HIVAN was rapidly progressive renal failure accompanied by moderate to severe nephrotic-range protein uria, bland urinary sediment, and the ultrasoun findings of large, highly echogenic kidneys. Patient progressed to ESRD within several months.

Although some cases have been reported in the setting of asymptomatic HIV infection or acute HIV seroconversion, HIVAN is typically a complication o advanced HIV disease. Thus HIV-infected patient who develop nephrotic-range proteinuria and have CD4 cell count less than 200 cells/mm³ should b strongly suspected of having HIVAN. A renal biopsy i required to establish the diagnosis and exclude othe causes of renal dysfunction and proteinuria, includin numerous HIV-related glomerular diseases, non-HIV related renal diseases, and medication nephrotoxicity Other glomerular lesions encountered in the HIV infected patient include thrombotic microangiopathy immune complex-mediated glomerular disease (such as membranoproliferative or membranous glomerulone phritis related to coinflection with hepatitis C or hepa titis B viruses, acute postinfectious glomerulonephritis lupus-like nephritis, and IgA nephropathy). Thes immune complex forms of glomerulonephritis are mor common in HIV-infected Caucasians than Africa Americans. Other renal biopsy findings in the age of antiretroviral therapy include hypertensive arterio nephrosclerosis and diabetic nephropathy.

In the acute phase, untreated HIVAN typically cause a dramatic pattern of collapsing FSGS. Glomerula capillary lumina are occluded by an implosive wrinkling and collapse of the glomerular basement membranes that is more often global than segmental. Tuft collapse is accompanied by prominent hypertrophy and hyperplasia of the overlying podocytes (visceral epithelial cells), which have enlarged; open vesicular nuclei with frequent nucleoli; and occasional mitotic figures. The podocyte cytoplasm is typically vacuolated, containing intracytoplasmic protein resorption (hyaline) droplets. Exuberant visceral and parietal epithelial cell proliferation can form pseudocrescents that obliterate the urinary space. Eventually, the glomerular tuft retracts into a tight, solidified ball crowned by enlarged, vacuolated visceral epithelial cells.