Diagnosis: HIV-Associated Nephropathy
• There are multiple subtypes of focal segmental glomerulosclerosis (FSGS), including the collapsing variant, the cellular variant, the tip lesion variant, the perihilar variant, and FSGS not otherwise specified. Among these variants, collapsing FSGS has the worst prognosis and a strong association with African American race.
• Collapsing FSGS can be either primary (idiopathic) or secondary. The most common secondary etiology of collapsing FSGS is HIV infection. Additional secondary etiologies of collapsing FSGS include parvovirus infection, hemophagocytic syndrome, acute vasoocclusive disease, and treatment with pamidronate or interferon.
• When collapsing FSGS is seen in the setting of HIV infection, the condition is referred to as HIVAN. Collapsing FSGS is the most common pattern of renal disease attributable to HIV infection.
• HIV-1 is able to infect directly and replicate within renal epithelial cells, including podocytes. Viral infection causes dysregulation of host genes, resulting in the development of collapsing FSGS.
• The incidence of HIVAN has been significantly reduced as a result of HAART for HIV infection.
