Immune reconstitution inflammatory syndrome after initiating highly active antiretroviral therapy in HIV-infected children

Tuberculosis Treatment Outcomes Among Children in Rural Southern Mozambique: A 12-year Retrospective Study

BACKGROUND

Globally, tuberculosis (TB) remains a serious cause of morbidity and mortality for children. Mozambique is 1 of 30 high TB and TB/HIV burden countries. This study aimed to assess treatment outcomes of childhood TB in Chókwè District, Mozambique.

METHODS

A retrospective cohort study of children <15-years-old treated for TB from 2006 to 2017 was conducted at Carmelo Hospital of Chókwè. Descriptive statistics were used to summarize patient characteristics. Treatment outcomes stratified by HIV status were compared with χ. Multivariable logistic regression was used to estimate the odds of a favorable TB treatment outcome. Kaplan-Meier curves were used to estimate the cumulative incidence of death.

RESULTS

Nine hundred thirty-three cases of childhood TB were enrolled, 45.9% of which were female and 49.6% were <5-years-old. Five hundred sixty-five (62%) children were HIV positive. Seven hundred sixty-two (83.6%) cases had a favorable TB treatment outcome. In comparison to children 0-4 years, the 5-14 age group had a higher odds of a favorable outcome [odds ratio: 2.02, 95% confidence interval: 1.42-3.05]. Being 5-14 years was associated with lower risk of death (hazard ratio: 0.435; 95% confidence interval: 0.299-0.632). Those starting anti-TB treatment ≤3 months after antiretroviral therapy initiation had a survival probability of approximately 75% at 1 year compared with 95% for those who were HIV negative.

CONCLUSIONS

Most children in this cohort had favorable TB treatment outcomes. Worse outcomes were observed for younger children and if anti-TB treatment started ≤3 months after initiation of antiretroviral therapy. Rigorous screening for TB and isoniazid preventative therapy may reduce the burden of TB in this population and lead to better outcomes.

Immune Reconstitution Inflammatory Syndrome in children

Immune Reconstitution Inflammatory Syndrome (IRIS) refers to a collection of inflammatory disorders, predominantly related to infectious processes that manifest after the initiation of antiretroviral therapy (ART) and can be classified as unmasking or paradoxical. The prevalence of IRIS in children in sub-Saharan Africa is low. Approximately half of all cases are associated with Mycobacterium tuberculosis. It may be difficult to distinguish IRIS from tuberculosis and other opportunistic infections radiologically; therefore, radiological findings must be interpreted with clinical and laboratory findings. In this review article, we describe the clinical and radiological manifestations of IRIS in children and provide illustrative radiological examples.

A systemic review of tuberculosis with HIV coinfection in children

The epidemiology of tuberculosis is adversely impacted by the human immunodeficiency virus (HIV) coinfection. HIV-infected patients are more prone to opportunistic infections, most commonly tuberculosis, and the risk of death in coinfected patients is higher than in those without HIV. Due to the impaired cellular immunity and reduced immunological response in HIV-infected patients, the classic imaging features of tuberculosis usually seen in patients without HIV may present differently. The aim of this review article is to highlight the imaging features that may assist in the diagnosis of tuberculosis in patients with HIV coinfection.

The chest X-ray features of chronic respiratory disease in HIV-infected children--a review

Several features of human immunodeficiency virus (HIV) infection contribute to the development of chronic respiratory disease in children. These include the frequency and severity of acute chest infections, as well as the increased risk of pulmonary tuberculosis, aspiration, cardiovascular disease, lymphocytic interstitial pneumonitis or pulmonary neoplasia. The chest radiograph (CXR) remains the most accessible investigation for respiratory disease and plays an important role in the baseline assessment and follow-up. This review focuses on the CXR abnormalities of HIV-related chronic respiratory disease in children. The most commonly documented chronic CXR abnormalities are homogeneous opacification and pulmonary nodules, with pulmonary tuberculosis and lymphocytic interstitial pneumonitis the leading respective causes. Deficiencies in radiographic reporting methodology and relative paucity of radiographic data contribute to current limitations in knowledge and understanding of this field. The review highlights the need for standardised terminology and systematic reporting methodology in future studies. Prospective research on the natural history of lymphocytic interstitial pneumonitis, response to anti-tuberculous therapy, the impact of anti-retroviral therapy and HIV-associated bronchiectasis are needed.

Tuberculosis Immune Reconstitution Inflammatory Syndrome in children initiating Antiretroviral Therapy for HIV infection: A systematic literature review

BACKGROUND

People with HIV initiating combination antiretroviral therapy are at risk for tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS). While this syndrome has been well researched in adults, little is known about the incidence, case fatality, underlying immunopathology and treatment approaches in children.

METHODS

Major databases were searched for articles related to TB-IRIS in children. Data were abstracted using standardized forms.

RESULTS

Thirteen studies were identified: 6 retrospective and 2 prospective cohort studies, 1 cross-sectional study, 3 case reports and 1 case series. In total, 303 cases of TB-IRIS were described, of which 270 were unmasking TB-IRIS, 12 paradoxical TB-IRIS and 21 were not classifiable due to lack of key information. None of the cohort studies had investigation of TB-IRIS as its primary aim. Nine studies were from Africa, 3 from Asia and 1 from Latin America. Age at cART initiation (reported by 12 studies) ranged from 1 month to 16 years. Median time from start of cART to IRIS diagnosis (reported by 8 studies) ranged from 8 days to 16 weeks. Few deaths attributable to TB-IRIS were recorded. Treatment was only discussed in 2 case studies, both of which reported children receiving corticosteroids. No studies evaluated risk factors for, or immunopathogenesis of, pediatric TB-IRIS.

CONCLUSIONS

There is a paucity of information available on TB-IRIS in children. Future research assessing incidence, risk factors, case fatality and optimal treatment or prevention strategies of TB-IRIS is needed.

CNS-immune reconstitution inflammatory syndrome in the setting of HIV infection, part 2: discussion of neuro-immune reconstitution inflammatory syndrome with and without other pathogens

SUMMARY

While the previous review of CNS-IRIS in the HIV-infected patient on highly active antiretroviral therapy (Part 1) dealt with an overview of the biology, pathology, and neurologic presentation of this condition and a discussion of the atypical imaging findings in PML-IRIS and cryptococcal meningitis-IRIS due to the robust inflammatory response, the current review (Part 2) discusses the imaging findings in other commonly encountered organisms seen in association with CNS-IRIS, namely, VZV, CMV, HIV, Candida organisms, Mycobacterium tuberculosis, and Toxoplasma gondii. Also described is the imaging appearance of CNS-IRIS when not associated with a particular organism. Recognition of these imaging findings will give credence to the diagnosis of CNS-IRIS and will allow the clinician to institute changes in medical management, if necessary, so that immune reconstitution and improved patient outcome can occur with time.

Paradoxical Mycobacterium tuberculosis meningitis immune reconstitution inflammatory syndrome in an HIV-infected child

Immune reconstitution inflammatory syndrome occurs in a subset of HIV-infected individuals as the immune system recovers secondary to antiretroviral therapy. An exaggerated and uncontrolled inflammatory response to antigens of viable or nonviable organisms is characteristic, with clinical deterioration despite improvement in laboratory indicators. We describe a fatal case of Mycobacterium tuberculosis meningitis immune reconstitution inflammatory syndrome in an HIV-infected child and review the literature.

CNS-immune reconstitution inflammatory syndrome in the setting of HIV infection, part 1: overview and discussion of progressive multifocal leukoencephalopathy-immune reconstitution inflammatory syndrome and cryptococcal-immune reconstitution inflammatory syndrome

SUMMARY

While uncommon, CNS-IRIS developing after the initiation of HAART in the setting of HIV-related severe immunosuppression is characterized by an intense inflammatory reaction to dead or latent organisms or to self-antigens due to a heightened but dysregulated immune response. While this reaction can range from mild to fulminating, encompassing a very wide clinical spectrum, it is important to recognize because changes in medical management may be necessary to prevent neurologic decline and even death. Once contained, however, this inflammatory response can be associated with improved patient outcome as immune function is restored. Among the infectious organisms that are most commonly associated with CNS-IRIS are the JC virus and Cryptococcus organisms, which will be the subject of this review. CD8 cell infiltration in the leptomeninges, perivascular spaces, blood vessels, and even parenchyma seems to be the pathologic hallmark of CNS-IRIS. While recognition of CNS-IRIS may be difficult, the onset of new or progressive clinical symptoms, despite medical therapy and despite improved laboratory data, and the appearance on neuroimaging studies of contrast enhancement, interstitial edema, mass effect, and restricted diffusion in infections not typically characterized by these findings in the untreated HIV-infected patient should raise the strong suspicion for CNS-IRIS. While CNS-IRIS is a diagnosis of exclusion, the neuroradiologist can play a critical role in alerting the clinician to the possibility of this syndrome.