Immune reconstitution inflammatory syndrome in patients starting antiretroviral therapy for HIV infection: a systematic review and meta-analysis

Universal testing and treatment as an HIV prevention strategy: research questions and methods

Achieving high coverage of antiretroviral treatment (ART) in resource-poor settings will become increasingly difficult unless HIV incidence can be reduced substantially. Universal voluntary counselling and testing followed by immediate initiation of ART for all those diagnosed HIV-positive (universal testing and treatment, UTT) has the potential to reduce HIV incidence dramatically but would be very challenging and costly to deliver in the short term. Early modelling work in this field has been criticised for making unduly optimistic assumptions about the uptake and coverage of interventions. In future work, it is important that model parameters are realistic and based where possible on empirical data. Rigorous research evidence is needed before the UTT approach could be considered for wide-scale implementation. This paper reviews the main areas that need to be explored. We consider in turn research questions related to the provision of services for universal testing, services for immediate treatment of HIV-positives and the population-level impact of UTT, and the research methods that could be used to address these questions. Ideally, initial feasibility studies should be carried out to investigate the acceptability, feasibility and uptake of UTT services. If these studies produce promising results, there would be a strong case for a cluster-randomised trial to measure the impact of a UTT intervention on HIV incidence, and we consider the main design features of such a trial.

Admissions to intensive care unit of HIV-infected patients in the era of highly active antiretroviral therapy: etiology and prognostic factors

INTRODUCTION

Although access to highly active antiretroviral therapy (HAART) has prolonged survival and improved life quality, HIV-infected patients with severe immunosuppression or comorbidities may develop complications that require critical care support in intensive care units (ICU). This study aimed to describe the etiology and analyze the prognostic factors of HIV-infected Taiwanese patients in the HAART era.

METHODS

Medical records of all HIV-infected adults who were admitted to ICU at a university hospital in Taiwan from 2001 to 2010 were reviewed to record information on patient demographics, receipt of HAART, and reason for ICU admission. Factors associated with hospital mortality were analyzed.

RESULTS

During the 10-year study period, there were 145 ICU admissions for 135 patients, with respiratory failure being the most common cause (44.4%), followed by sepsis (33.3%) and neurological disease (11.9%). Receipt of HAART was not associated with survival. However, CD4 count was independently predictive of hospital mortality (adjusted odds ratio [AOR], per-10 cells/mm3 decrease, 1.036; 95% confidence interval [CI], 1.003 to 1.069). Admission diagnosis of sepsis was independently associated with hospital mortality (AOR, 2.91; 95% CI, 1.11 to 7.62). A hospital-to-ICU interval of more than 24 hours and serum albumin level (per 1-g/dl decrease) were associated with increased hospital mortality, but did not reach statistical significance in multivariable analysis.

CONCLUSIONS

Respiratory failure was the leading cause of ICU admissions among HIV-infected patients in Taiwan. Outcome during the ICU stay was associated with CD4 count and the diagnosis of sepsis, but was not associated with HAART in this study.

Secondary Buruli ulcer skin lesions emerging several months after completion of chemotherapy: paradoxical reaction or evidence for immune protection?

Background

The neglected tropical disease Buruli ulcer (BU) caused by Mycobacterium ulcerans is an infection of the subcutaneous tissue leading to chronic ulcerative skin lesions. Histopathological features are progressive tissue necrosis, extracellular clusters of acid fast bacilli (AFB) and poor inflammatory responses at the site of infection. After the recommended eight weeks standard treatment with rifampicin and streptomycin, a reversal of the local immunosuppression caused by the macrolide toxin mycolactone of M. ulcerans is observed.

Methodology/Principal Findings

We have conducted a detailed histopathological and immunohistochemical analysis of tissue specimens from two patients developing multiple new skin lesions 12 to 409 days after completion of antibiotic treatment. Lesions exhibited characteristic histopathological hallmarks of Buruli ulcer and AFB with degenerated appearance were found in several of them. However, other than in active disease, lesions contained massive leukocyte infiltrates including large B-cell clusters, as typically found in cured lesions.

Conclusion/Significance

Our histopathological findings demonstrate that the skin lesions emerging several months after completion of antibiotic treatment were associated with M. ulcerans infection. During antibiotic therapy of Buruli ulcer development of new skin lesions may be caused by immune response-mediated paradoxical reactions. These seem to be triggered by mycobacterial antigens and immunostimulators released from clinically unrecognized bacterial foci. However, in particular the lesions that appeared more than one year after completion of antibiotic treatment may have been associated with new infection foci resolved by immune responses primed by the successful treatment of the initial lesion.

Buruli ulcer (BU) is a chronic necrotizing skin disease presenting with extensive tissue destruction and local immunosuppression. Standard treatment recommended by the WHO includes 8 weeks of rifampicin/streptomycin and, if necessary, wound debridement and skin grafting. In some patients satellite lesions develop close to the primary lesion or occasionally also at distant sites during effective antibiotic treatment of the primary lesion. We performed a detailed analysis of tissue specimens from lesions that emerged in two BU patients from Benin 12 to 409 days after completion of chemotherapy. Histopathology revealed features of tissue destruction typically seen in BU and degenerated acid-fast bacilli. In addition, lesions contained organized immune infiltrates typically found in successfully treated BU lesions. Secondary lesions emerging many months after completion of chemotherapy may have been caused by immune response-mediated paradoxical reactions. However, the late onset may also indicate that they were associated with new infection foci spontaneously resolved by adaptive immune responses primed by antibiotic treatment of the primary lesions.

Síndrome de restauração imune associada à histoplasmose

Paciente masculino, 27 anos, portador de HIV, com quadro de histoplasmose cutânea disseminada. Terapia antirretroviral oral e anfotericina B por via EV (dose total acumulada 0,5g) foram introduzidas, verificando-se rápida cicatrização das lesões após duas semanas. A anfotericina B foi substituída por itraconazol (200mg/dia). O paciente interrompeu voluntariamente os tratamentos. A terapia antirretroviral foi reintroduzida, havendo aumento da contagem de células T CD4-positivas (No restante do texto, a autora usa o símbolo "+" (T CD4+) ao invés da palavra "positiva". O que fazer neste caso? Seguimos o padrão do restante do texto ou acatamos essa opção da autora no resumo?!). Neste momento, diagnosticou-se histoplasmose ganglionar. O aumento da contagem de células T CD4-positivas (de novo aqui), associado à redução da carga viral a níveis inferiores ao limite de detecção após a reintrodução da terapia antirretroviral, sugere que essa piora clínica paradoxal seja uma síndrome de restauração imune

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.

Tuberculosis in special populations

The susceptibility to infection, the pathogenesis and the clinical manifestations of tuberculosis (TB) depend on the immunological status of the host. Immunological status is largely determined by age and comorbidities, but is also affected by other less well known factors. In Spain, most incidental cases of TB arise from the reactivation of remotely acquired latent infections and are favored by the aging of the population and the use of aggressive immunosuppressive therapies. The diagnosis and management of TB in these circumstances is often challenging. On the one hand, the atypical presentation with extrapulmonary involvement may delay diagnosis, and on the other, the toxicity and interactions of the antituberculous drugs frequently make treatment difficult. Immigration from resource-poor, high incidence TB countries, where the social and economic conditions are often suboptimal, adds a new challenge to the control of the disease in Spain. This chapter summarizes our current knowledge of epidemiological, clinical and treatment aspects of TB in particularly susceptible populations.

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.

Tuberculosis

Tuberculosis results in an estimated 1·7 million deaths each year and the worldwide number of new cases (more than 9 million) is higher than at any other time in history. 22 low-income and middle-income countries account for more than 80% of the active cases in the world. Due to the devastating effect of HIV on susceptibility to tuberculosis, sub-Saharan Africa has been disproportionately affected and accounts for four of every five cases of HIV-associated tuberculosis. In many regions highly endemic for tuberculosis, diagnosis continues to rely on century-old sputum microscopy; there is no vaccine with adequate effectiveness and tuberculosis treatment regimens are protracted and have a risk of toxic effects. Increasing rates of drug-resistant tuberculosis in eastern Europe, Asia, and sub-Saharan Africa now threaten to undermine the gains made by worldwide tuberculosis control programmes. Moreover, our fundamental understanding of the pathogenesis of this disease is inadequate. However, increased investment has allowed basic science and translational and applied research to produce new data, leading to promising progress in the development of improved tuberculosis diagnostics, biomarkers of disease activity, drugs, and vaccines. The growing scientific momentum must be accompanied by much greater investment and political commitment to meet this huge persisting challenge to public health. Our Seminar presents current perspectives on the scale of the epidemic, the pathogen and the host response, present and emerging methods for disease control (including diagnostics, drugs, biomarkers, and vaccines), and the ongoing challenge of tuberculosis control in adults in the 21st century.

Etiology of suspected pneumonia in adults admitted to a high-dependency unit in Blantyre, Malawi

The microbiologic etiology of severe pneumonia in hospitalized patients is rarely known in sub-Saharan Africa. Through a comprehensive diagnostic work-up, we aimed to identify the causative agent in severely ill patients with a clinical picture of pneumonia admitted to a high-dependency unit. A final diagnosis was made and categorized as confirmed or probable by using predefined criteria. Fifty-one patients were recruited (45% females), with a mean age of 35 years (range = 17-88 years), of whom 11(22%) died. Forty-eight (94%) of the patients were seropositive for human immunodeficiency virus; 14 (29%) of these patients were receiving antiretroviral treatment. Final diagnoses were bacterial pneumonia (29%), Pneumocystis jirovecii pneumonia (27%), pulmonary tuberculosis (22%), and pulmonary Kaposi's sarcoma (16%); 39 (77%) of these cases were confirmed cases. Fifteen (29%) patients had multiple isolates. At least 3 of 11 viral-positive polymerase chain reaction (PCR) results of bronchoalveolar lavage fluid were attributed clinical relevance. No atypical bacterial organisms were found.

Association of age with mortality and virological and immunological response to antiretroviral therapy in rural South African adults

OBJECTIVE

To assess whether treatment outcomes vary with age for adults receiving antiretroviral therapy (ART) in a large rural HIV treatment cohort.

DESIGN

Retrospective cohort analysis using data from a public HIV Treatment & Care Programme.

METHODS

Adults initiating ART 1(st) August 2004-31(st) October 2009 were stratified by age at initiation: young adults (16-24 years) mid-age adults (25-49 years) and older (≥50 years) adults. Kaplan-Meier survival analysis was used to estimate mortality rates and age and person-time stratified Cox regression to determine factors associated with mortality. Changes in CD4 cell counts were quantified using a piecewise linear model based on follow-up CD4 cell counts measured at six-monthly time points.

RESULTS

8846 adults were included, 808 (9.1%) young adults; 7119 (80.5%) mid-age adults and 919 (10.4%) older adults, with 997 deaths over 14,778 person-years of follow-up. Adjusting for baseline characteristics, older adults had 32% excess mortality (p = 0.004) compared to those aged 25-49 years. Overall mortality rates (MR) per 100 person-years were 6.18 (95% CI 4.90-7.78); 6.55 (95% CI 6.11-7.02) and 8.69 (95% CI 7.34-10.28) for young, mid-age and older adults respectively. In the first year on ART, for older compared to both young and mid-aged adults, MR per 100 person-years were significantly higher; 0-3 months (MR: 27.1 vs 17.17 and 21.36) and 3-12 months (MR: 9.5 vs 4.02 and 6.02) respectively. CD4 count reconstitution was lower, despite better virological response in the older adults. There were no significant differences in MR after 1 year of ART. Baseline markers of advanced disease were independently associated with very early mortality (0-3 months) whilst immunological and virological responses were associated with mortality after 12 months.

CONCLUSIONS

Early ART initiation and improving clinical care of older adults are required to reduce high early mortality and enhance immunologic recovery, particularly in the initial phases of ART.

Initiating antiretrovirals during tuberculosis treatment: a drug safety review

INTRODUCTION

Integrating HIV and tuberculosis (TB) treatment can reduce mortality substantially. Practical barriers to treatment integration still exist and include safety concerns related to concomitant drug use because of drug interactions and additive toxicities. Altered therapeutic concentrations may influence the chances of treatment success or toxicity.

AREAS COVERED

The available data on drug-drug interactions between the rifamycin class of anti-mycobacterials and the non-nucleoside reverse transcriptase inhibitor and the protease inhibitor classes of antiretrovirals are discussed with recommendations for integrated use. Additive drug toxicities, the impact of immune reconstitution inflammatory syndrome (IRIS) and the latest data on survival benefits of integrating treatment are elucidated.

EXPERT OPINION

Deferring treatment of HIV to avoid drug interactions with TB treatment or the occurrence of IRIS is not necessary. In the integrated management of TB-HIV co-infection, rational drug combinations aimed at reducing toxicities while effecting TB cure and suppressing HIV viral load are possible.

Impact of the immune reconstitution inflammatory syndrome (IRIS) on mortality and morbidity in HIV-infected patients in Mexico

OBJECTIVES

To estimate the impact of immune reconstitution inflammatory syndrome (IRIS) on morbidity and mortality in patients starting highly-active antiretroviral therapy (HAART).

METHODS

A retrospective cohort study of HIV-positive patients starting HAART was conducted at a tertiary care referral center in Mexico City. We estimated the incidence of IRIS, hospitalizations and death rates during the first 2 years of HAART. The relative risk of death (RR) and hospitalization for patients with IRIS were adjusted for relevant covariates using regression methods.

RESULTS

During the 2-year follow-up period, 27% of patients developed IRIS (14 IRIS cases per 100 person-years). The relative risk of death among patients who developed IRIS was 3 times higher (95% confidence interval (CI) 1.19-7.65, p = 0.03). After adjusting for previous opportunistic infections we still observed a higher death rate among patients with IRIS (RR 2.3, 95% CI 0.9-5.9, p=0.09). An effect modification of IRIS over mortality was observed by previous opportunistic infection.

CONCLUSIONS

IRIS-associated mortality is strongly confounded by previous opportunistic infection. Patients with AIDS who eventually developed IRIS had the highest risk of death at the 2-year follow-up.

Incidence and risk factors of serious adverse events during antituberculous treatment in Rwanda: a prospective cohort study

Background

Tuberculosis (TB) and TB-human immunodeficiency virus infection (HIV) coinfection is a major public health concern in resource-limited settings. Although TB treatment is challenging in HIV-infected patients because of treatment interactions, immunopathological reactions, and concurrent infections, few prospective studies have addressed this in sub-Saharan Africa.

In this study we aimed to determine incidence, causes of, and risk factors for serious adverse events among patients on first-line antituberculous treatment, as well as its impact on antituberculous treatment outcome.

Methods and findings

Prospective observational cohort study of adults treated for TB at the Internal Medicine department of the Kigali University Hospital from May 2008 through August 2009.

Of 263 patients enrolled, 253 were retained for analysis: median age 35 (Interquartile range, IQR 28–40), 55% male, 66% HIV-positive with a median CD4 count 104 cells/mm³ (IQR 44–248 cells/mm³). Forty percent had pulmonary TB, 43% extrapulmonary TB and 17% a mixed form. Sixty-four (26%) developed a serious adverse event; 58/167 (35%) HIV-infected vs. 6/86 (7%) HIV-uninfected individuals. Commonest events were concurrent infection (n = 32), drug-induced hepatitis (n = 24) and paradoxical reactions/TB-IRIS (n = 23).

HIV-infection (adjusted Hazard Ratio, aHR 3.4, 95% Confidence Interval, CI 1.4–8.7) and extrapulmonary TB (aHR 2, 95%CI 1.1–3.7) were associated with an increased risk of serious adverse events. For TB/HIV co-infected patients, extrapulmonary TB (aHR 2.0, 95%CI 1.1–3.9) and CD4 count <100 cells/mm3 at TB diagnosis (aHR 1.7, 95%CI 1.0–2.9) were independent predictors. Adverse events were associated with an almost two-fold higher risk of unsuccessful treatment outcome at 6 months (HR 1.89, 95%CI 1.3–3.0).

Conclusion

Adverse events frequently complicate the course of antituberculous treatment and worsen treatment outcome, particularly in patients with extrapulmonary TB and advanced immunodeficiency. Concurrent infection accounts for most events. Our data suggest that deterioration in a patient already receiving antituberculous treatment should prompt an aggressive search for additional infections.

HIV-associated Hodgkin lymphoma during the first months on combination antiretroviral therapy

Hodgkin lymphoma (HL) incidence with HIV infection may have increased with the introduction of combination antiretroviral therapy (cART), suggesting that immune reconstitution may contribute to some cases. We evaluated HL risk with cART during the first months of treatment. With 187 HL cases among 64 368 HIV patients in France, relative rates (RRs) and 95% confidence intervals (CIs) of HL were estimated using Poisson models for duration of cART, CD4 count, and HIV load, with and without adjustment for demographic/clinical covariates. HL risk was unrelated to cART use overall, but it was related to time intervals after cART initiation (P = .006). Risk was especially and significantly elevated in months 1-3 on cART (RR 2.95, CI 1.64-5.31), lower in months 4-6 (RR 1.63), and null with longer use (RR 1.00). CD4 count was strongly associated with HL risk (P < 10⁻⁶), with the highest HL incidence at 50-99 CD4 cells/mm³. With adjustment for CD4 count and covariates, HL risk was elevated, but not significantly (RR 1.42), in months 1-3 on cART. HIV load had no added effect. HL risk increased significantly soon after cART initiation, which was largely explained by the CD4 count. Further studies of HIV-associated HL are needed.

Optimum time to start antiretroviral therapy during HIV-associated opportunistic infections

PURPOSE OF REVIEW

We review recently published literature concerning the optimum time to start antiretroviral therapy (ART) in patients with HIV-associated opportunistic infections.

RECENT FINDINGS

In addition to data from observational studies, results from six randomized controlled clinical trials were available by July 2010. The collective findings of these trials were that patients with CD4 cell counts less than 200 cells/μl who start ART within the first 2 weeks of treatment for opportunistic infections including Pneumocystis jirovecii pneumonia, serious bacterial infections or pulmonary tuberculosis have lower mortality when compared to patients starting ART at later time-points. Moreover, patients with pulmonary tuberculosis and CD4 counts of 200-500 cells/μl who started ART during tuberculosis (TB) treatment had improved survival compared to those who deferred ART until after the end of treatment. In contrast, in two separate studies, immediate ART conferred no survival benefit in patients with TB meningitis and was associated with substantially higher mortality risk in patients with cryptococcal meningitis.

SUMMARY

Initiation of ART during the first 2 weeks of treatment for serious opportunistic infections has been shown to be associated with improved survival with the exception of patients with tuberculous meningitis and cryptococcal meningitis. Further clinical trials are ongoing.

The Clinical Significance of CD4 Counts in Asian and Caucasian HIV-Infected Populations: Results from TAHOD and AHOD

The significance of interethnic variation in CD4 counts between Asian and Caucasian populations is not known. Patients on combination antiretroviral therapy from Treat Asia and Australian HIV Observational Databases (TAHOD, predominantly Asian, n = 3356; and AHOD, predominantly Caucasian, n = 2312, respectively) were followed for 23 144 person-years for AIDS/death and all-cause mortality endpoints. We calculated incidence-rates and used adjusted Cox regression to test for the interaction between cohort (TAHOD/AHOD) and time-updated CD4 count category (lagged by 3 months) for each of the endpoints. There were 382 AIDS/death events in TAHOD (rate: 4.06, 95%CI: 3.68-4.50) and 305 in AHOD (rate: 2.39, 95%CI: 2.13-2.67), per 100 person-years. At any given CD4 count category, the incidence-rates of endpoints were found to be similar between TAHOD and AHOD (in the adjusted models, P > .05 for the interaction term between cohort type and latest CD4 counts). At any given CD4 count, risk of AIDS or death was not found to vary by ethnicity, suggesting that the CD4 count thresholds for predicting outcomes defined in Caucasian populations may be equally valid in Asian populations.

Tuberculosis in HIV programmes in lower-income countries: practices and risk factors

BACKGROUND

Tuberculosis (TB) is a common diagnosis in human immunodeficiency virus (HIV) infected patients on antiretroviral treatment (ART).

OBJECTIVE

To describe TB-related practices in ART programmes in lower-income countries and identify risk factors for TB in the first year of ART.

METHODS

Programme characteristics were assessed using standardised electronic questionnaire. Patient data from 2003 to 2008 were analysed and incidence rate ratios (IRRs) calculated using Poisson regression models.

RESULTS

Fifteen ART programmes in 12 countries in Africa, South America and Asia were included. Chest X-ray, sputum microscopy and culture were available free of charge in respectively 13 (86.7%), 14 (93.3%) and eight (53.3%) programmes. Eight sites (53.3%) used directly observed treatment and five (33.3%) routinely administered isoniazid preventive treatment (IPT). A total of 19 413 patients aged ≥ 16 years contributed 13,227 person-years of follow-up; 1081 new TB events were diagnosed. Risk factors included CD4 cell count (>350 cells/μl vs. <25 cells/μl, adjusted IRR 0.46, 95%CI 0.33-0.64, P < 0.0001), sex (women vs. men, adjusted IRR 0.77, 95%CI 0.68-0.88, P = 0.0001) and use of IPT (IRR 0.24, 95%CI 0.19-0.31, P < 0.0001).

CONCLUSIONS

Diagnostic capacity and practices vary widely across ART programmes. IPT prevented TB, but was used in few programmes. More efforts are needed to reduce the burden of TB in HIV co-infected patients in lower income countries.

Skin infections in HIV-infected individuals in the era of HAART

PURPOSE OF REVIEW

Clinicians should be aware of the shift in the cutaneous infectious disease burden in human immunodeficiency virus-infected individuals as a reflection of immune restoration in the era of highly active antiretroviral therapy (HAART).

RECENT FINDINGS

As in the general population but to greater extent, methicillin-resistant Staphylococcus aureus (MRSA) soft-tissue infection is a rising problem among those with human immunodeficiency virus (HIV). Human papilloma virus (HPV) is exceedingly prevalent and persistent despite HAART, and HPV-associated malignancy is increasing as those with HIV live longer. Herpes, syphilis, and Kaposi's sarcoma continue to plague individuals with HIV. Immune reconstitution inflammatory syndrome (IRIS) is common and often presents with infectious cutaneous manifestations.

SUMMARY

This review implicates the importance of the acknowledgment of MRSA infections risk factors, screening for HPV-related neoplasia, continuance of trials to establish the efficacy of herpes vaccines, and awareness of prevalent cutaneous infections presenting with IRIS in those with HIV.

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.

Type B insulin resistance syndrome associated with an immune reconstitution inflammatory syndrome in an HIV-infected woman

CONTEXT

Type B insulin resistance syndrome is a rare condition characterized by the presence of autoantibodies directed against the insulin receptor. It has been reported in association with autoimmune diseases such as systemic lupus erythematosus.

OBJECTIVE

We report a case of type B insulin resistance syndrome in a patient with HIV infection on highly active antiretroviral therapy (HAART).

PATIENT AND METHODS

A 27-yr-old African woman with ketosis-prone diabetes and HIV infection developed severe insulin resistance after the initiation of HAART. Standard oral glucose tolerance tests using 75 g of glucose performed 1, 2, and 3 months after the initiation of HAART showed severe hyperinsulinemia and hypoglycemia. Six months later, she developed symptomatic hyperglycemia resistant to high-dose insulin therapy. To determine the cause of insulin resistance, we assayed the titer of insulin receptor autoantibodies in the serum of the patient.

RESULTS

Plasma insulin receptor autoantibodies were present at the time of marked hyperglycemia and insulin resistance, confirming the diagnosis of type B insulin resistance syndrome. Simultaneously the diagnosis of immune reconstitution inflammatory syndrome was established according to increased CD4 T cell count, decreased plasma HIV1-RNA level, and tuberculosis reactivation, shortly after institution of HAART. Corticosteroid therapy improved insulin resistance and hyperglycemia.

CONCLUSION

We report the first case of type B insulin resistance syndrome associated with immune reconstitution inflammatory syndrome in an HIV-infected patient.

Human immunodeficiency virus and leprosy: an update

Coinfection with human immunodeficiency virus (HIV) has a major effect on the natural history of many infectious diseases, particularly mycobacterial diseases. Early in the HIV epidemic, it was predicted that HIV infection would worsen leprosy outcomes, with more patients developing lepromatous disease, an impaired response to multidrug therapy and fewer reactions. However, studies on the epidemiologic and clinical aspects of leprosy suggest that the course of leprosy in coinfected patients has not been greatly altered by HIV. In contrast, initiation of antiretroviral treatment has been reported to be associated with activation of subclinical Mycobacterium leprae infection and exacerbation of existing leprosy lesions. With regular new discoveries about the interaction of leprosy and HIV, the need to maintain research in this field is of considerable importance.

Immunopathological characteristics of immune reconstitution inflammatory syndrome caused by Mycobacterium parascrofulaceum infection in a patient with AIDS

Immune reconstitution inflammatory syndrome (IRIS) caused by mycobacterium in patients with AIDS is often experienced in clinical practice. There is, however, a paucity of data documenting the histopathological findings and the pathogenesis. We determined the immunopathological characteristics of IRIS associated with Mycobacterium parascrofulaceum infection in an AIDS patient. A patient presented with pulmonary lymphadenitis and involvement of the pulmonary lingular segment. Portions of the involved lymph nodes and lung were excised, and the immunological properties were analyzed by immunohistochemical assays. The histological characteristics of lymph nodes showed a caseous necrosis. Histopathologically, the pulmonary lesion was composed of exudative and proliferative lesions. CD4(+), CD8(+), CD57(+), and CD25(+)/FoxP3(+) cells were observed in both types of lesions. Clusters of CD20(+) cells and GATA3(+) cells were predominantly observed in exudative lesions, while T-bet(+) cells were dominant in proliferative lesions. ROR-γ(+) cells were also observed in exudative lesions. These results indicate that the cellular immunity to mycobacteria was recovering in the lung tissue. In M. parascrofulaceum pulmonary infection, the exudative lesion had characteristics of Th2 and Th17-type immunities. In contrast, the proliferative lesion had characteristics of Th-1 type immunity. Our data provide the first evidence to reveal the status of the axis of distinctive immunity in the process of granuloma formation caused by a mycobacterium-related infection.

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.

Targeting γδ T cells for immunotherapy of HIV disease

Disruption of circulating γδ T-cell populations is an early and common outcome of HIV infection. T-cell receptor (TCR)-γ2δ2 cells (expressing the Vγ2 and Vδ2 chains of the γδ TCR) are depleted, even though they are minimally susceptible to direct HIV infection, and exemplify indirect cell depletion mechanisms that are important in the progression to AIDS. Among individuals with common or normally progressing HIV disease, the loss of TCR-γ2δ2 cells has a broad impact on viral immunity, control of opportunistic pathogens and resistance to malignant disease. Advanced HIV disease can result in complete loss of TCR-γ2δ2 cells that are not recovered even during antiretroviral therapy with complete virus suppression. However, normal levels of TCR-γ2δ2 were observed among natural virus suppressors (low or undetectable virus without antiretroviral therapy) irrespective of their MHC haplotype, consistent with their disease-free status. The pattern of loss and recovery of TCR-γ2δ2 cells revealed their unique features and functional capacities, and encourage the development of immune-based therapies to activate and expand this T-cell subset. New research has identified drugs that might reconstitute the TCR-γ2δ2 population, recover their functional contributions, and improve control of HIV replication and disease. Here, we review research on HIV and TCR-γδ T cells to highlight the consequences of depleting this subset and the unique features of TCR-γδ biology that argue in favor of clinical strategies to reconstitute this T-cell subset in individuals with HIV/AIDS.

Stem cell-based approaches to treating HIV infection

PURPOSE OF REVIEW

Stem cell-based strategies for treating HIV-infected individuals represent a novel approach toward reconstituting the ravaged immune system with the ultimate aim of clearing the virus from the body. Genetic modification of human hematopoietic stem cells to produce cells that are either resistant to infection, cells that produce lower amounts of infectious virus, or cells that specifically target the immune response against the virus are currently the dominant strategies under development. This review focuses on the understanding of stem cell-based approaches that are under investigation and the rationale behind such approaches.

RECENT FINDINGS

Significant progress has recently been made utilizing stem cell-based approaches to treat HIV infection. Ideally, a successful strategy would result in immune clearance of the virus from the body as well long-term restoration of overall immune responses to successfully combat everyday environmental antigens. Two recent clinical trails illustrate how new advances in stem cell-based approaches may propel this field forward to clinical reality: one that demonstrates that large-scale gene therapy trials can be performed in a conventional, reproducible manner; and one that demonstrates the utilization of a multipronged approach using lentiviral-based gene therapy vectors. These clinical trails serve as the foundation for the development of other technologies, discussed here, that are currently in preclinical development.

SUMMARY

Recent advances using stem cell-based approaches to treat HIV infection have provided the impetus for a renewed and expanded interest in the development of new cell-based strategies to treat HIV infection as well as a variety of other diseases.

Development of cytomegalovirus (CMV) immune recovery uveitis is associated with Th17 cell depletion and poor systemic CMV-specific T cell responses

We tested whether impaired systemic immunoregulation and hyperactive immune responses are associated with an immune reconstitution inflammatory syndrome, CMV IRU. We found instead that T-regs in CMV IRU patients are functionally intact, while virus-specific immune responses and Th17 cells are compromised

Background. The immune reconstitution inflammatory syndromes (IRIS) are a spectrum of inflammatory conditions associated with opportunistic infections and occurring in ∼16% of human immunodeficiency type 1 (HIV-1)–infected patients given antiretroviral therapy. It has been proposed that these conditions are linked by a dysregulated immune system that is prone to exaggerated responses. However, immunologic studies have been limited by the availability of longitudinal samples from patients with IRIS and appropriate matched control subjects. Cytomegalovirus (CMV) immune recovery uveitis (IRU) is an IRIS occurring in up to 38% of patients with CMV retinitis. Although the pathologic immune responses occur in the eye, immune dysregulation that allows for development of pathologic responses is presumably caused by faulty systemic immune cell reconstitution.

Methods. We examined CMV-specific T cell responses, regulatory T (T_reg) cell function and polyclonal T cell responses, including IL-17 production, in 25 patients with CMV IRU and 49 immunorestored control subjects with CMV retinitis who did not develop IRU.

Results. Patients with CMV IRU had poor CMV-specific CD4⁺ T cell responses, as compared with control subjects, whereas CD8⁺ T cell responses were comparable. Patients with CMV IRU were characterized by smaller numbers of circulating Th17 cells. Deficiency in anti-CMV responses was not associated with differences in T_reg cell function.

Conclusions. The T_reg cell compartment is intact in patients with CMV IRU, and these patients do not develop exaggerated systemic CMV-specific or polyclonal immune responses. Cases are instead characterized by more profound depletion of Th17 cells and poor antiviral immune responses. CMV IRU may be most likely to develop in persons experiencing the greatest degree of immune dysfunction before initiating highly active antiretroviral therapy.

The immune reconstitution inflammatory syndrome and antiretroviral therapy

Although generally mild, severe immune reconstitution inflammatory syndrome may complicate antiretroviral therapy, and it may be difficult to differentiate from treatment failure or toxicity. This article looks at diagnostic and therapeutic challenges of severe infectious manifestations of immune reconstitution inflammatory syndrome.

Antiretroviral treatment 2010: progress and controversies

Effective antiretroviral therapy (ART) changes the clinical course of HIV infection. There are 25 antiretroviral drugs approved for the treatment of HIV infection, and current antiretroviral drug regimens are highly effective, convenient, and relatively nontoxic. ART regimens should be chosen in consideration of a patient's particular clinical situation. Successful treatment is associated with durable suppression of HIV viremia over years, and consequently, ART reduces the risk of clinical progression. In fact, current models estimate that an HIV-infected individual appropriately treated with antiretroviral drugs has a life expectancy that approaches that of the general HIV-uninfected population, although some patient groups such as injection drug users do less well. Despite these advances, continued questions about ART persist: What is the optimal time to start ART? What is the best regimen to start? When is the optimal time to change ART? What is the best regimen to change to? In addition, newer antiretroviral agents are in development, both in existing classes and in new classes such as the CD4 receptor attachment inhibitors and the maturation inhibitors. Further research will help optimize current antiretroviral treatments and strategies.

Tuberculous meningitis in patients infected with human immunodeficiency virus

Tuberculosis is the most common opportunistic infection in human immunodeficiency virus (HIV) infected persons. HIV-infected patients have a high incidence of tuberculous meningitis as well. The exact incidence and prevalence of tuberculous meningitis in HIV-infected patients are not known. HIV infection does not significantly alter the clinical manifestations, laboratory, radiographic findings, or the response to therapy. Still, some differences have been noted. For example, the histopathological examination of exudates in HIV-infected patients shows fewer lymphocytes, epithelioid cells, and Langhan's type of giant cells. Larger numbers of acid-fast bacilli may be seen in the cerebral parenchyma and meninges. The chest radiograph is abnormal in up to 46% of patients with tuberculous meningitis. Tuberculous meningitis is likely to present with cerebral infarcts and mass lesions. Cryptococcal meningitis is important in differential diagnosis. The recommended duration of treatment in HIV-infected patients is 9-12 months. The benefit of adjunctive corticosteroids is uncertain. Antiretroviral therapy and antituberculosis treatment should be initiated at the same time, regardless of CD4 cell counts. Tuberculous meningitis may be a manifestation of paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome. Some studies have demonstrated a significant impact of HIV co-infection on mortality from tuberculous meningitis. HIV-infected patients with multidrug-resistant tuberculous meningitis have significantly higher mortality. The best way to prevent HIV-associated tuberculous meningitis is to diagnose and isolate infectious cases of tuberculosis promptly and administer appropriate treatment.

HIV-Associated Tuberculosis

The intersecting HIV and Tuberculosis epidemics in countries with a high disease burden of both infections pose many challenges and opportunities. For patients infected with HIV in high TB burden countries, the diagnosis of TB, ARV drug choices in treating HIV-TB coinfected patients, when to initiate ARV treatment in relation to TB treatment, managing immune reconstitution, minimising risk of getting infected with TB and/or managing recurrent TB, minimizing airborne transmission, and infection control are key issues. In addition, given the disproportionate burden of HIV in women in these settings, sexual reproductive health issues and particular high mortality rates associated with TB during pregnancy are important. The scaleup and resource allocation to access antiretroviral treatment in these high HIV and TB settings provide a unique opportunity to strengthen both services and impact positively in meeting Millennium Development Goal 6.

Risk factors for immune reconstitution inflammatory syndrome under combination antiretroviral therapy can be aetiology-specific

In order to discriminate general from aetiology-specific risk factors for immune reconstitution inflammatory syndrome (IRIS), we followed up, during six months, 99 patients with advanced HIV infection commencing antiretroviral therapy (ART) without active opportunistic infections or evident inflammation. IRIS predictors were determined by univariate analysis using clinical data from 76 ART-responding patients either completing follow-up or developing IRIS, and by multivariate analysis of inflammation, disease progression and nutrition status variables. We identified 23 primary IRIS events (30.3%). Univariate predictors for all IRIS events were higher platelet counts and lower CD4/CD8 ratio, whereas subclinical inflammation was the multivariate predictor. Platelets, alkaline phosphatase levels and %CD8 T-cells in univariate analysis also predicted mycobacteria-associated IRIS independently, remaining elevated during follow-up. Herpesvirus IRIS was predicted by platelets and inflammation. Indicators of advanced HIV disease and subclinical inflammation jointly predict IRIS, and some are specific of the underlying microbial aetiology, possibly explaining previous reports.