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HIV associated immune complex (HIVIC)
What is HIVIC and why is it helpful for a rheumatologist to be aware of this HIV-associated condition?
HIV-associated immune complex refers to the formation of immune complexes in individuals infected with the human immunodeficiency virus (HIV). Immune complexes are formed when antibodies bind to antigens, such as viral particles or other foreign substances, in the body. In the case of HIV infection, the presence of the virus can lead to the formation of immune complexes that circulate in the bloodstream.
In HIV infection, immune complexes can have both positive and negative effects on the immune system. Here are a few key points:
- Antigen-Antibody Interaction: HIV infection triggers the production of specific antibodies against the virus. These antibodies can bind to viral antigens, forming immune complexes.
- Clearance and Immune Response: Immune complexes help in the clearance of viral particles by facilitating their recognition and removal by immune cells, such as macrophages. This is part of the body’s immune response to control the virus.
- Inflammation and Tissue Damage: However, excessive formation and deposition of immune complexes in tissues can lead to chronic inflammation and tissue damage. This can contribute to various complications and manifestations seen in HIV infection, such as glomerulonephritis (kidney inflammation) or vasculitis (blood vessel inflammation).
- Immune Complex Disease: Some individuals with HIV may develop immune complex diseases, which are conditions characterized by the deposition of immune complexes in tissues, leading to inflammation and organ damage. Examples include immune complex-mediated glomerulonephritis or skin manifestations like vasculitis or purpura.
Management of HIV-associated immune complex-related conditions typically involves treating the underlying HIV infection with antiretroviral therapy (ART) to suppress viral replication and reduce immune activation. Additional therapies may be considered based on the specific manifestations and organ involvement.
It is important to note that the management of HIV infection and associated complications should be undertaken by healthcare professionals with expertise in HIV care. They can provide appropriate diagnostic evaluation, treatment, and ongoing management based on individual circumstances and considerations.
Some studies suggest that HIV-associated immune complex (HIVIC) kidney disease is now the most common pathologic finding among renal biopsy specimens from patients with HIV.
Patients typically present with renal insufficiency, proteinuria, active urinary sediment, and hypocomplementemia.
A wide range of histopathologic findings have been described in HIVIC, including a lupus-like glomerulonephritis with a “full-house pattern” (IgG, IgM, IgA, C3, C1q) on immunofluorescence.
These features may be mistaken for SLE; therefore, recognition of HIVIC is important to the rheumatologist.
HIVICK is due to HIV infection, with aberrant immune regulation and increased gamma globulin contributing to immune complex formation.
This may involve HIV p24 (capsid) and gp120 (envelope) antigens as targets. APOL1 risk allele variants, common in African Americans, are not associated with increased frequency of HIVICK.
Coinfection with hepatitis B and C should be ruled out as should other coexistent diseases such as cryoglobulinemia and DILS that may also act through immune complex deposition.
Treatment includes ART, and in some situations, consideration of immunosuppression (controversial given the paucity of data; may consider corticosteroids and additional medications in severe cases such as crescentic glomerulonephritis).
Patients with HIV infection exhibit unique immunologic characteristics, including immunodeficiency and dysregulation of immunoglobulin synthetic responses and T-cell function, which can result in glomerular immune complex deposition and subsequent kidney injury.
A Review examines the differential diagnoses of HIV-associated immune complex kidney diseases (HIVICD), and discusses the clinical manifestations and mechanisms underlying their development. This review address the issues associated with treatment, clinical outcomes, and research needs to enhance our ability to diagnose and optimally treat patients with HIVICD.
