Introduction:
HIV Nephropathy occurs in patients infected by a virus called HIV, which eventually leads to acute renal failure. These viruses infect the renal tissues and replicate within them, causing damage to the renal tissues. It can be defined as collapsing glomerulopathy as it affects the glomerular capillaries, causing obstruction and altering kidney function. The renal epithelium is found to be the reservoir of HIV infection, which harbors the transcriptionally active viruses.
What Is the History Behind HIV Nephropathy?
The first case of HIV Nephropathy was reported in 1984 in Newyork 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 Is HIV Nephropathy?
It is a disease 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 HIV?
The human Immunodeficiency virus is an RNA virus that belongs to the retrovirus family. It is a sexually transmitted infection that causes a serious illness in humans called AIDS, which suppresses the immune system paving the way for the development of life-threatening opportunistic infections, carcinomas, and other serious disorders.
What Is the Epidemiology of HIV Nephropathy?
The incidence of HIV Nephropathy was high in the 1990s because of the lack of knowledge and poor treatment facilities. Studies report that it is predominantly seen among African descendants, but the recent statistics show that the prevalence of the disease has decreased comparatively due to the implementation of combined antiretroviral therapies, which limits the disease process.
What Is the Etiology 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 involves
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Direct expression and replication of the HIV genes in the kidneys - This causes direct damage to the kidney by the viral gene products.
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Immune dysregulation - Caused by the increased viral activity in the body.
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Drug-induced nephrotoxicity.
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Maybe due to the release of cytokines as a response to HIV infection.
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Indirect injury to the kidneys due to other comorbidities caused by HIV infection.
What Is the Pathogenesis of HIV Nephropathy?
The exact mechanism of how the HIV cells affect the kidney is still unclear because the main receptors required for the virus to enter T-cells are absent in the kidney. The lymphocytes such as CD 209 antigen and lymphocyte antigen 75 are found to be directly involved in the infection of renal tubular epithelial cells. The HIV proteins such as Vpr and tat that circulate in the plasma and lipids have access to the specialized epithelial cells that cover the surface of the glomerular capillaries called podocytes, thereby gaining entry into the renal tissues and causing infection.
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:
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Proteinuria - Excretion of protein in the urine.
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Pyuria - Increased white blood cells (WBC) in urine.
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Bland Urinary Sediment - Urine sediment will be bland without the presence of intrinsic elements.
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Microhematuria - Small traces of blood in urine, which can be appreciated by microscopic examination only.
How Is HIV Nephropathy Diagnosed?
The vital methods involved in the diagnosis of HIV Nephropathy involve:
1. History and Clinical Examination
Collecting proper history from the patient regarding the preexisting disease and the appropriate clinical examination is the first and foremost thing to be considered.
2. Laboratory Findings
This includes:
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Tests to confirm HIV in affected individuals.
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Urine analysis for the presence of proteinuria.
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Urine analysis to find out pyuria and to evaluate urinary sediments.
3. Light Microscopic Findings
Histopathological findings reveal:
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The collapse of the glomerular basement membrane.
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Occlusion of the glomerular capillaries.
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Hypertrophy and hyperplasia of the podocytes.
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Visceral epithelial cells appear clouded, which obstructs the urinary space.
4. Immunofluorescence Findings
The immunofluorescence findings reveal the segmental deposition of IgM and C3 in the collapsed glomeruli. Visceral epithelial cells show positive staining for IgG, IgA, and Albumin.
What Are All the Differential Diagnosis of HIV Nephropathy?
The conditions to be considered as a differential diagnosis for HIV Nephropathy may include
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HIV-Associated Immune Complex Kidney Disease -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.
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Amyloidosis - Is characterized by the deposition of abnormal proteinaceous material in different organs, causing damage.
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Diabetic Nephropathy - It occurs due to poor control of blood sugar levels affecting the filtering capacity of the kidneys.
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IgA Nephropathy - It is characterized by the deposition of IgA antibodies in the kidney, causing damage to the renal tissues.
How to Manage HIV Nephropathy?
The main aim of managing this condition is to prevent the disease from progressing to end-stage renal disease.
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Combined Antiretroviral Therapy - This is the mainstay of treatment in HIV Nephropathy as it limits the disease from progressing to renal failure.
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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.
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Renal Transplantation Surgery - It 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.
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Corticosteroids - Can be considered in patients who do not respond to initial treatment.
What Is the Prognosis of HIV Nephropathy?
HIV 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. But the prognosis of HIV Nephropathy is bad when compared to nephropathy due to other causes.
What Are the Complications of HIV Nephropathy?
The most common complications of HIV Nephropathy are:
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Chronic kidney disease- Chronic kidney disease may develop as a complication as the kidneys lose their function permanently.
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Renal failure - Complete loss of kidney function due to the effect of the virus.
Other rare complications include:
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Hypertension- It may develop as a result of disturbed renin aldosterone mechanism due to poor kidney function.
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Edema- It may occur as a consequence of progressing kidney disease.
Conclusion
HIV 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.