HIV Nephropathy - Causes, Clinical Manifestations, Diagnosis, and Treatment

What Is HIV Nephropathy?

It is a condition affecting the kidneys in patients infected by HIV. It is also known as HIV-associated nephropathy and has evolved as one of the important causes of chronic kidney disease and renal failure.

What Is the History Behind HIV and Nephropathy?

The first case of HIV nephropathy was reported in 1984 in New York City. Within a few years of the first reported case, it was identified as one of the major complications of acquired immunodeficiency syndrome (AIDS), affecting the majority of the population. In 1999, it was found to be the third leading cause of end-stage renal disease.

What Are the Causes of HIV Nephropathy?

As stated earlier, it is exclusively seen in patients infected with HIV. The possible factors involved in the rapid progression of the disease include:

• Direct expression and replication of the HIV genes in the kidneys - This causes direct damage to the kidney by the viral gene products.

• Immune dysregulation - Caused by the increased viral activity in the body.

• Drug-induced nephrotoxicity.

• Maybe due to the release of cytokines as a response to HIV infection.

• Indirect injury to the kidneys due to other comorbidities caused by HIV infection.

What Is the Diagnosis of HIV-Associated Nephropathy?

HIV-associated nephropathy (HIVAN) is a kidney disease that is commonly observed in patients with HIV, especially in African Americans. The following are the steps involved in the diagnosis of this disease:

1. Clinical and Laboratory Diagnosis:

• History and Clinical Examination: A proper history of the patient and clinical examination are necessary.

• Laboratory Tests: Evaluation for HIV infection must be done in addition to urinalysis, searching for proteinuria (protein within the urine) and pyuria (white blood cells within the urine).

1. Microscopic Findings:

• Light Microscopy: The renal biopsy demonstrates flattening of the glomerular basement membrane with capillary occlusion and alteration of podocytes.

• Immunofluorescence: Glomeruli showing segmental deposits of IgM and C3, the cells are stained positive for IgG, IgA, and albumin.

1. Diagnostic Features:

• HIV Associated Kidney Disease: Approximately 10 to 15 percent of people with HIV suffer from kidney issues. Albuminuria is another condition where the patient has albumin in his urine. It causes kidney failure if left untreated.

• Progression of Kidney Failure: HIVAN can rapidly progress to end-stage renal disease (ESRD), and most patients are on dialysis within three years if left untreated.

• Effect of Treatment: Combination antiretroviral therapy (cART) has decreased the incidence of HIVAN.

1. Kidney Biopsy Findings:

• Light Microscopy: Glomerular damage and inflammation in the tubules of the kidney, with lymphocytes.

• Immunofluorescence: Minimal immune deposits, with some nonspecific protein stains in the damaged areas.

• Electron Microscopy: Filtration barrier damage with swelling and formation of protein buildup by podocytes and the presence of tubuloreticular aggregates in cells of blood vessels is seen more often in untreated HIV patients.

What Are All the Differential Diagnosis of HIV Nephropathy?

The conditions to be considered as a differential diagnosis for HIV-associated nephropathy may include:

• HIV-Associated Immune Complex Kidney Disease -This is characterized by the dysregulation of the immunoglobulin synthetic responses and deposition of the immune complex in the glomeruli, thereby causing injury to the kidneys.

• Amyloidosis - This is characterized by the deposition of abnormal proteinaceous material in different organs, causing damage.

• Diabetic Nephropathy - It occurs due to poor control of blood sugar levels affecting the filtering capacity of the kidneys.

• IgA Nephropathy - It is characterized by the deposition of IgA antibodies in the kidney, causing damage to the renal tissues.

What Is the Treatment of HIV-Associated Nephropathy?

The main aim of managing this condition is to prevent the disease from progressing to end-stage renal disease.

• Combined Antiretroviral Therapy - This is the mainstay of treatment in HIV-associated nephropathy as it limits the disease from progressing to renal failure.

• Angiotensin-Converting Enzyme (ACE) inhibitor or Angiotensin Receptor Blocker (ARB) - These drugs are aimed at blocking the Renin-angiotensin-aldosterone system (RAAS) which has been found to improve the kidney function in addition to antiretroviral therapy.

• Renal Transplantation Surgery - This should be considered in patients who have developed an end-stage renal disease, and it is found to be effective in patients with controlled HIV.

• Corticosteroids - Can be considered in patients who do not respond to initial treatment.

What Is the Prognosis of HIV Nephropathy?

HIV-associated Nephropathy was reported to be an aggressive disease with a poor prognosis till the implementation of antiretroviral therapy in the treatment of this disease. After the introduction of antiretroviral therapy, the prognosis of the disease has improved considerably. However, the prognosis of HIV-associated nephropathy is bad when compared to nephropathy due to other causes.

What Are the Complications of HIV Nephropathy?

The most common complications of HIV associated Nephropathy are:

• Chronic Kidney Disease- Chronic kidney disease may develop as a complication as the kidneys lose their function permanently.

• Renal Failure - Complete loss of kidney function due to the effect of the virus.

Other rare complications include:

• Hypertension- It may develop as a result of disturbed renin aldosterone mechanism due to poor kidney function.

• Edema- It may occur as a consequence of progressing kidney disease.

What Are the Clinical Manifestations of HIV Nephropathy?

It is a rapidly progressive renal disease that may lead to end-stage renal disease in no time once it gains entry into the nephrons. The accompanying signs and symptoms include:

• Proteinuria - Excretion of protein in the urine.

• Pyuria - Increased white blood cells (WBC) in urine.

• Bland Urinary Sediment - Urine sediment will be bland without the presence of intrinsic elements.

• Microhematuria - Small traces of blood in urine, which can be appreciated by microscopic examination only.

Conclusion:

HIV-associated nephropathy is a rapidly progressive disease that needs to be addressed earlier. Prompt diagnosis and treatment of the underlying condition are essential to prevent the development of renal failure. Regular follow-up and frequent kidney function tests are necessary for susceptible individuals.