Abstract:
Introduction
IRIS is a paradoxical inflammatory response in HIV/AIDS patients,
occurring in 4-35% of cases after starting ART, especially in those
with CD4 counts <100 cells/μL. It typically appears within 1-3 months
and includes two forms: worsening of known opportunistic infections
and unmasking of undiagnosed ones. Its manifestations are
influenced by the interaction between ART, infections, and the host
immune response.
Material and methods
An examination of systematic reviews and other publications in
English from the past decade, utilising sources such as PubMed,
Elsevier, BMJ, and the CDC and WHO.
Results
Elevated HIV viral loads prior to the initiation of ART, in conjunction
with brief intervals between the start of OI treatment and the
initiation of ART, lower pre-treatment CD4+ cell counts and a rapid
increase in CD4+ cells following the commencement of ART,
contribute to an increased risk of IRIS. No notable differences in
gender, mode of transmission, and ART regimens were noted
between the IRIS and non-IRIS patients. Region-specific IRIS includes
cryptococcal meningitis (CM) and tuberculosis (TB), which are prevalent in sub-Saharan Africa and Southeast Asia; Talaromyces
marneffei skin lesions have been identified in northern Thailand and
Vietnam. In Latin America, CM, histoplasmosis, and paracoccidioidomycosis constitute significant fungal infections; mucocutaneous leishmaniasis has been observed in Bolivia and Peru. In
the Americas and Europe, common conditions include Progressive
Multifocal Leukoence-phalopathy (PML), CMV retinitis, and noninfectious issues related to IRIS. Other notable cases often involve
the Mycobacterium avium complex, Kaposi's sarcoma (KS), hepatitis
HBV/HCV, and, in migrants, tuberculosis (TB). Children under the age
of 15 are at a higher risk of IRIS (∼26% vs. 10-20% in adults), often
presenting with suppurative lymphadenitis following BCG vaccination
and CMV retinitis. The decline in thymic function among the elderly
alters T-regulatory responses; thus, in adults aged 15-49, a
paradoxical worsening of TB and cryptococcal infections is common.
For individuals over 50, IRIS is associated with atypical non-infectious
conditions (such as rheumatological disorders), non-Hodgkin
lymphoma, KS, and elevated mortality rates (∼25% vs. 15% in
younger adults). Healthcare factors that elevate the risk of IRIS
include delayed diagnosis, late ART initiation, and low CD. To
minimise IRIS mortality, testing for TB and cryptococcal infections
during pre-ART screening is essential in Africa and Asia; fluconazole
prophylaxis is necessary in areas where cryptococcal infections are
endemic; and screening for malignancies is important for older
adults.
Conclusions
Although the fundamental immunological risk factors for IRIS are the
same worldwide, its manifestations vary based on the local
prevalence of opportunistic infections. This variation is also
influenced by host immunity, age-related vulnerabilities, and the
availability of healthcare and diagnostic resources.
