Predictors of immune reconstitution inflammatory syndrome-associated with kaposi sarcoma in mozambique: a prospective study

Alterations in T cell subsets in human immunodeficiency virus-infected adults with co-infections in southern Mozambique

T cell activation and depletion of naive T cells are hallmarks of human immunodeficiency virus (HIV) pathogenesis. This study explored the relationships between certain co-infections (including syphilis, hepatitis B and C, human T cell lymphotrophic viruses I and II [HTLV-I/II], Kaposi sarcoma-associated herpesvirus [KSHV], Plasmodium falciparum malaria, and tuberculosis), and levels of activated CD8 and CD4 T cell subsets as well as naive and memory CD4 T cells in HIV-infected adults in a rural area of southern Mozambique. We found that syphilis infection and to a lesser extent HTLV-I/II seropositivity were independently associated with higher CD8 T cell activation (CD8+ CD38+ HLA-DR+) whereas only syphilis was associated with higher CD4 T cell activation. Furthermore, KSHV and HTLV-I/II seropositivities were independently associated with a lower percentage of naive CD4 T cells (CD4+ CD45RA+ CD62L+). These results highlight the importance of screening and prompt treatment of syphilis, and raise questions as to whether HIV-positive persons with certain chronic viral co-infections should initiate combined antiretroviral therapy at higher CD4 cell counts.

Paradoxical immune reconstitution inflammatory syndrome in HIV-infected patients treated with combination antiretroviral therapy after AIDS-defining opportunistic infection

BACKGROUND

The incidence of immune reconstitution inflammatory syndrome (IRIS) when antiretroviral therapy (ART) is initiated after an AIDS-defining opportunistic infection (OI) is uncertain and understudied for the most common OIs.

METHODS

We examined patients in the University of Washington Human Immunodeficiency Virus Cohort initiating potent ART subsequent to an AIDS-defining OI. IRIS was determined through retrospective medical record review and adjudication using a standardized data collection process and clinical case definition. We compared demographic and clinical characteristics, and immunologic changes in patients with and without IRIS.

RESULTS

Among 196 patients with 260 OIs, 21 (11%; 95% confidence interval, 7%-16%) developed paradoxical IRIS in the first year on ART. The 3 most common OIs among study patients were Pneumocystis pneumonia (PCP, 28%), Candida esophagitis (23%), and Kaposi sarcoma (KS, 16%). Cumulative 1-year incidence of IRIS was 29% (12/41) for KS, 16% (4/25) for tuberculosis, 14% (1/7) for Cryptococcus, 10% (1/10) for Mycobacterium avium complex, and 4% (3/72) for PCP. Morbidity and mortality were highest in those with visceral KS-IRIS compared with other types of IRIS (100% [6/6] vs 7% [1/15], P < .01). Patients with mucocutaneous KS and tuberculosis-IRIS experienced greater median increase in CD4(+) cell count during the first 6 months of ART compared with those without IRIS (+158 vs +53 cells/μL, P = .04, mucocutaneous KS; +261 vs +113, P = .04, tuberculosis).

CONCLUSIONS

Cumulative incidence and features of IRIS varied depending on the OI. IRIS occurred in >10% of patients with KS, tuberculosis, or Cryptococcus. Visceral KS-IRIS led to considerable morbidity and mortality.

Pathogenesis and prevention of immune reconstitution disease during antiretroviral therapy

The risks of unmasking and paradoxical forms of immune reconstitution disease in HIV-infected patients starting antiretroviral therapy (ART) are fuelled by a combination of the late presentation of patients with advanced immunodeficiency, the associated high rates of opportunistic infections (OIs) and the need for rapid initiation of ART to minimize overall mortality risk. We review the risk factors and our current knowledge of the immunopathogenesis of immune reconstitution disease, leading to a discussion of strategies for prevention. Initiation of ART at higher CD4 counts, use of OI-preventive therapies prior to ART eligibility, intensified screening for OIs prior to ART initiation and optimum therapy for OIs are all needed. In addition, use of a range of pharmacological agents with immunosuppressive and immunomodulatory activity is being explored.

Pulmonary manifestations of the immune reconstitution inflammatory syndrome

PURPOSE OF REVIEW

Immune reconstitution inflammatory syndrome (IRIS) is a common occurrence in HIV patients starting antiretroviral therapy (ART), and pulmonary involvement is an important feature of tuberculosis-IRIS and pneumocystis-IRIS. Pulmonologists need an awareness of the timing, presentation and treatment of pulmonary IRIS.

RECENT FINDINGS

Case definitions for tuberculosis-IRIS and cryptococcal-IRIS have been published by the International Network for the Study of HIV-associated IRIS (INSHI). A number of studies have addressed validation of clinical case definitions and the optimal time to commence ART after diagnosis of an opportunistic infection in HIV patients. The pathogenesis of IRIS is being assessed at a molecular level, increasing our understanding of mechanisms and possible targets for future preventive and therapeutic strategies.

SUMMARY

Tuberculosis-IRIS, nontuberculosis mycobacterial-IRIS and pneumocystis-IRIS occur within days to weeks of starting ART, causing substantial morbidity, but low mortality. Cryptococcal-IRIS usually occurs later in the course of ART, and may be associated with appreciable mortality. Early recognition of unmasking and paradoxical IRIS affecting the lung allows timely initiation of antimicrobial and/or immunomodulatory therapies.

Immune reconstitution and risk of Kaposi sarcoma and non-Hodgkin lymphoma in HIV-infected adults

OBJECTIVE

Given the well documented occurrence of immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients who recently started combination antiretroviral therapy (cART), we examined whether cART initiation increased the risk of Kaposi sarcoma and non-Hodgkin lymphoma (NHL) using data from the Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) collaboration.

DESIGN

A nested matched case-control study design was used to assess the effects of individual CD4 cell trajectories and exposure to cART close to the time of cancer diagnosis.

METHODS

Cases were patients diagnosed with either cancer during follow-up with a minimum of two consecutive CD4 cell readings within the year preceding diagnosis. For each case, up to 10 controls, matched by sex and cohort, were selected by random sampling. Changes in CD4 cell count, calculated by simple and piecewise linear regression, and recent exposure to cART were compared within matched case-control sets using conditional logistic regression.

RESULTS

Using data on 689 cases and 4588 controls, we found that an initially low and decreasing CD4 cell count during the year prior to cancer diagnosis is predictive of both Kaposi sarcoma and NHL. Most of this cancer risk is explained by the immunodeficiency characteristic of the period before cART initiation; however, an increased cancer risk was seen in patients who initiated cART in the previous 3 months (odds ratio 2.31; 95% confidence interval 1.33, 4.00).

CONCLUSION

Although IRIS may transiently increase the risk of Kaposi sarcoma or NHL in HIV-infected patients, the timely initiation of cART remains the best strategy to avoid the development of these malignancies.

Rapid suppression of HIV-RNA is associated with improved control of immune activation in Mozambican adults initiating antiretroviral therapy with low CD4 counts

The rapidity of HIV-RNA suppression after initiation of combined antiretroviral therapy (cART) may impact immune reconstitution in developing countries, where patients initiate cART at low CD4 T cell counts. One hundred and thirty-five HIV-1 Mozambican adults initiating cART were prospectively followed over 16 months within a larger observational study. Plasma HIV-RNA, CD4 counts, and CD8 T cell activation were monitored at the pre-cART visit and at 4, 10, and 16 months during cART. Of the 89 patients with available HIV-RNA data at pre-cART and 4 and 10 months post-cART, 68% (60/89) suppressed HIV-RNA at 4 months and were defined as "early virological controllers"(EC). Twenty of the 29 remaining patients who did not control HIV-RNA at 4 months did so at 10 months and were classified as "late virological controllers"(LC). Nine (10%) patients did not control HIV-RNA at either time point. Both initiating an EFV-containing cART regimen and having pre-cART tuberculosis were significantly associated with early HIV-RNA suppression if locked into a multivariate model [EFV OR: 13.6 (95% CI 1.7; 108.1) p = 0.014) tuberculosis OR: 11.0 (95% CI 1.4; 87.9) p = 0.024]. EC demonstrated significantly lower median activated CD8 T cells at 4, 10, and 16 months post-cART than did LC. Approximately 63% (12/19) of LC experienced reappearance of detectable HIV-RNA at 6 months postcontrol as compared to 15% (2/60) of EC (p = 0.001). This study suggests that rapid suppression of HIV-RNA may lead to a lower rate of reappearance of HIV-RNA, which could impact CD8 T cell activation levels in patients initiating cART at low CD4 counts.

Update on KSHV epidemiology, Kaposi Sarcoma pathogenesis, and treatment of Kaposi Sarcoma

Much has been learned since the discovery of KSHV in 1994 about its epidemiology and pathology but much of what has been learned has yet to be translated into clinical practice. In this review, we survey the current state of knowledge on KSHV epidemiology and KS pathogenesis and highlight therapeutic opportunities in both the developed and developing world.

Incidence and predictors of immune reconstitution inflammatory syndrome in a rural area of Mozambique

Background

There is limited data on the epidemiology of Immune Reconstitution Inflammatory Syndrome (IRIS) in rural sub-Saharan Africa. A prospective observational cohort study was conducted to assess the incidence, clinical characteristics, outcome and predictors of IRIS in rural Mozambique.

Methods

One hundred and thirty-six consecutive antiretroviral treatment (ART)-naïve HIV-1-infected patients initiating ART at the Manhiça district hospital were prospectively followed for development of IRIS over 16 months. Survival analysis by Cox regression was performed to identify pre-ART predictors of IRIS development.

Results

Thirty-six patients developed IRIS [26.5%, incidence rate 3.1 cases/100 persons-month of ART (95% CI 2.2–4.3)]. Median time to IRIS onset was 62 days from ART initiation (IQR 35.5–93.5). Twenty-five cases (69.4%) were “unmasking”, 10 (27.8%) were “paradoxical”, and 1 (2.8%) developed a paradoxical worsening followed by the unmasking of another condition. Systemic OI (OI-IRIS) accounted for 47% (17/36) of IRIS cases, predominantly of KS (8 cases) and TB (6 cases) IRIS. Mucocutaneous IRIS manifestations (MC-IRIS) accounted for 53% (19/36) of IRIS events, mostly tinea (9 cases) and herpes simplex infection (3 cases). Multivariate analysis identified two independent predictors of IRIS development: pre-ART CD4 count <50 cells/µl (HR 2.3, 95% CI 1.19–4.44, p = 0.01) and body mass index (BMI) <18.5 (HR 2.15, 95% CI 1.07–4.3, p = 0.03). The pre-cART proportion of activated T-cells, as well as the immunologic and virologic response to ART were not associated with IRIS development. All patients continued on ART, 7 (19.4%) required hospitalization and there were 3 deaths (8.3%) attributable to IRIS.

Conclusions

IRIS is common in patients initiating ART in rural Mozambique. Pre-ART CD4 counts and BMI can easily be assessed at ART initiation in rural sub-Saharan Africa to identify patients at high risk of IRIS, for whom close supervision is warranted.

Biomarkers in immune reconstitution inflammatory syndrome: signals from pathogenesis

PURPOSE OF REVIEW

Immune reconstitution inflammatory syndrome (IRIS) is the paradoxical worsening or unmasking of an infection or neoplasm in HIV-1-infected patients shortly after antiretroviral therapy (ART) initiation. New insights into the pathogenesis of IRIS may help identify biomarkers that could be useful in predicting or diagnosing IRIS.

RECENT FINDINGS

Studies of immunopathogenesis have shown a signification activation of both innate and adaptive immune responses with elevation of plasma or serum chemokines and cytokines. Markers of inflammation such as C-reactive protein, interferon-inducible protein 10 or interferon γ may be helpful as predictors of IRIS events. In addition, tuberculosis (TB)-associated IRIS is associated with a prominent Th1 response that can be heightened even prior to ART initiation in cases of unmasking TB, and may assist in early diagnosis. Large prospective studies are needed to elucidate the predictive and diagnostic value of IRIS biomarkers and advance them to the clinic.

SUMMARY

Reversal of immunosuppression by ART leads to exaggerated pathogen-specific immune responses (known as IRIS) that appear to be primed prior to therapy. Inflammatory markers, chemokines and cytokines that signify innate and adaptive immune activation are biomarkers that could prove of clinical value after appropriate validation.

Immune reconstitution inflammatory syndrome

Immune reconstitution inflammatory syndrome (IRIS) must be considered in the differential diagnosis for any patient infected with HIV who has begun ART in the preceding months. Distinguishing between manifestations of IRIS and active infection is of paramount importance and poses a diagnostic challenge to the provider in the acute care setting. Presentations of IRIS are often atypical for the precipitating pathogen, and novel presentations are likely. Of the diseases associated with IRIS, mycobacteria and cryptococcal infections are commonly encountered, as are dermatologic symptoms in general. The most clinically significant complications of IRIS are those involving the central nervous system, lungs, and eye, and in many of these scenarios systemic steroids may be of benefit. Management should rarely include interruption of ART, except possibly in severe, life-threatening complications.