Health & Medical AIDS & HIV

The TB Immune Reconstitution Inflammatory Syndrome in HIV

The TB Immune Reconstitution Inflammatory Syndrome in HIV

Abstract and Introduction

Abstract


The Immune Reconstitution Inflammatory Syndrome (IRIS) in Ethiopian HIV-infected patients coinfected with tuberculosis (TB) was studied. HIV-infected outpatients initiating antiretroviral therapy (ART) at an HIV clinic in northern Ethiopia from January 2007 through September 2008 were identified (n = 1977). Patients with TB-IRIS occurring within 6 months of starting ART (n = 143) were compared with a control group of patients with HIV who began ART but did not develop TB-IRIS (n = 277). ART was not interrupted in any patient. Eleven (8%) patients with TB-IRIS died. New or "unmasked" TB with accompanying IRIS occurred in 132 or 92% of the cases. Worsening or "paradoxical" TB (ie, already known to be present and treated) was accompanied by IRIS in 11 (8%) patients. There was no significant difference between "unmasked" and "paradoxical" cases with respect to presentation of disease and outcome. Only a low baseline CD4 count (mean: 102 cells/μL) and a past history of World Health Organization (WHO) Clinical Stage 3 or 4 were associated with TB-IRIS (P < .05). The clinical manifestations of TB-IRIS were diverse, requiring a high index of suspicion. For example, pleural disease occurred in 13 patients, TB lymphadenitis in 17, intracranial TB in 9 patients, and disseminated TB in 15 patients. The majority of patients (88%) responded to continuation of ART and TB therapy. Thus, TB-IRIS is common in Ethiopian patients beginning ART, occurring in 7% of patients initiating antiretroviral therapy.

Introduction


Since its introduction, potent antiretroviral therapy (ART) has led to significant improvements in the quality of life of patients with HIV coinfected with tuberculosis (TB) by decreasing the incidence of TB and reconstituting immunity. However, some patients initiating ART experience a paradoxical clinical deterioration due to opportunistic infections that worsen or arise during immune recovery, thus leading to the Immune Reconstitution Inflammatory Syndrome (IRIS). IRIS may be due to infectious or noninfectious causes. The symptoms are the result of a dysregulated inflammatory response to a variety of opportunistic infections including TB. In general, IRIS is defined as a clinical worsening due to either (a) a previously unrecognized subclinical opportunistic pathogen arising after beginning ART ("unmasking" IRIS) or (b) a previously known and treated opportunistic pathogen that worsens in the setting of effective ART ("paradoxical" IRIS). IRIS can present any time after the initiation of ART, but the majority of cases occur within 90 days of initiation of ART.

Tuberculosis (TB) is a common disease associated with IRIS in developing countries, especially sub-Saharan Africa. Clinical manifestations of TB-IRIS include fever and worsening of previous pulmonary symptoms. Pleural effusions and mediastinal lymphadenopathy are common. Other symptoms are nonspecific and include fever, weight loss, and worsening of pulmonary symptoms. Rare forms of TB-IRIS include intracranial tuberculoma and disseminated tuberculosis. Paradoxical central nervous system TB has been reported to occur later as compared to other TB-IRIS, often 5 to 10 months after beginning ART.

There is a high burden of HIV-TB coinfection in Ethiopia. and the number of patients beginning ART is increasing. Patients with HIV infected with TB constitute one of the most difficult medical management problems. Despite this fact, there is limited data addressing TB-IRIS in Ethiopia. Knowledge gained from studying TB-IRIS may lead to a change in patient management that could decrease the incidence of TB-IRIS and thus decrease the burden on health facilities caring for these patients. Thus, we set out to determine the incidence of TB-IRIS in our HIV-infected patient population and when it arose after beginning ART.

You might also like on "Health & Medical"

Leave a reply