HIV associated nephropathy

HIV-associated nephropathy (HIVAN) is a progressive kidney disease characterized by damage to the filters in the kidneys that are responsible for removing waste from the body. It is most commonly observed in patients with advanced HIV infection, and it is considered one of the most severe complications of HIV, leading to chronic kidney disease (CKD) and, ultimately, end-stage renal disease (ESRD) if left untreated. The condition is particularly prevalent among African-American populations.

Etiology and Pathogenesis

The exact mechanism by which HIV causes nephropathy is not fully understood, but it is believed to involve direct infection of renal epithelial cells by the virus. This leads to a series of events including cellular proliferation, dedifferentiation, and the secretion of cytokines and chemokines, which ultimately result in glomerulosclerosis and tubulointerstitial fibrosis. Genetic factors, such as variations in the APOL1 gene, have also been implicated in the susceptibility to HIVAN, particularly among individuals of African descent.

Clinical Presentation

Patients with HIVAN typically present with varying degrees of proteinuria, often in the nephrotic range (>3.5 g/day), and rapidly progressive renal failure. Other common findings include edema, hypertension, and microscopic hematuria. The diagnosis is usually suspected in HIV-positive patients presenting with these symptoms and is confirmed through renal biopsy, which shows collapsing focal segmental glomerulosclerosis (FSGS) as the hallmark pathological finding.

Treatment

The management of HIVAN primarily involves the use of antiretroviral therapy (ART) to control HIV replication. ART has been shown to significantly slow the progression of kidney disease and improve renal function in many patients. Additionally, angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are used to reduce proteinuria and control blood pressure. In advanced cases, renal replacement therapy (dialysis) or kidney transplantation may be necessary.

Prevention and Screening

Early detection and treatment of HIV infection are crucial in preventing the development of HIVAN. Regular screening for kidney disease is recommended for all HIV-infected individuals, with a focus on those with high-risk factors such as African ancestry or a family history of kidney disease. This includes monitoring of serum creatinine, estimation of glomerular filtration rate (GFR), and urinalysis for proteinuria.

Prognosis

The introduction of effective ART has significantly improved the prognosis for patients with HIVAN. However, those who develop ESRD still have a poorer outcome compared to the general population with ESRD. Early diagnosis and aggressive treatment of both HIV and kidney disease are essential for improving survival rates.

Epidemiology

HIVAN is most commonly seen in patients with untreated or advanced HIV infection and is more prevalent among individuals of African descent. The widespread use of ART has led to a decrease in the incidence of HIVAN in developed countries; however, it remains a significant cause of kidney disease among HIV-infected individuals worldwide.