Immune restoration diseases reflect diverse immunopathological mechanisms

Reactivation of Varicella-Zoster Virus in Patients with Lung Cancer Receiving Immune Checkpoint Inhibitors: Retrospective Nationwide Population-Based Cohort Study from South Korea

BACKGROUND

This study aimed to determine the association between immune checkpoint inhibitors (ICIs) and the risk of herpes zoster (HZ) incidence in patients with lung cancer.

METHOD

We obtained national claims data of 51,021 patients from South Korea with lung cancer between August 2017 and December 2021. The study population was classified into ICI and non-ICI groups based on the prescription of ICIs at least once during the study period. To estimate the effects of ICIs treatment compared with those without ICIs treatment on HZ incidence, we used the Cox proportional hazards model adjusted for sex, age, comorbidities, and concomitant use of immunosuppressive drugs. Stratified analyses based on sex, age, and comorbidities were conducted to identify corresponding risk factors.

RESULTS

Of the 51,021 study participants, 897 (1.8%) were prescribed ICIs and 2262 (4.4%) were diagnosed with HZ. Approximately 75.6% of the patients receiving ICIs were male, and the prevalence of diabetes, cardiovascular disease, and chronic lung disease in the ICI group was significantly lower than that in the non-ICIs group. The Kaplan-Meier plot showed that the probability of incidence of HZ in the ICIs group was lower than that in the non-ICIs group. Additionally, treatment with ICIs was associated with a 31% lower incidence of developing HZ when compared to that seen without ICIs treatment (95% confidence interval [CI], 0.48-1.00). This association was stronger in females (hazard ratio [HR], 0.42; 95% CI, 0.19-0.94) and those less than 68 years of age (HR, 0.58; 95% CI, 0.34-0.99).

CONCLUSIONS

In these real-world data from an Asian population with lung cancer, ICIs treatment might be associated with a reduced risk of HZ compared to that without ICIs treatment.

Insights Into the Coinfections of Human Immunodeficiency Virus-Hepatitis B Virus, Human Immunodeficiency Virus-Hepatitis C Virus, and Hepatitis B Virus-Hepatitis C Virus: Prevalence, Risk Factors, Pathogenesis, Diagnosis, and Treatment

Human immunodeficiency virus, hepatitis B virus, and hepatitis C virus are three blood-borne viruses that can cause major global health issues by increasing severe morbidity. There is a high risk of coinfection with these viruses in individuals because of their same transmission routes through blood using shared needles, syringes, other injection equipment, sexual transmission, or even vertical transmission. Coinfection can cause various liver-related illnesses, non-hepatic organ dysfunction, followed by death compared to any of these single infections. The treatment of coinfected patients is complicated due to the side effects of antiviral medication, resulting in drug resistance, hepatotoxicity, and a lack of required responses. On the other hand, coinfected individuals must be treated with multiple drugs simultaneously, such as for HIV either along with HBV or HCV and HBV and HCV. Therefore, diagnosing, treating, and controlling dual infections with HIV, HBV, or HCV is complicated and needs further investigation. This review focuses on the current prevalence, risk factors, and pathogenesis of dual infections with HIV, HBV, and HCV. We also briefly overviewed the diagnosis and treatment of coinfections of these three blood-borne viruses.

Systemic Inflammation Associated with Immune Reconstitution Inflammatory Syndrome in Persons Living with HIV

Antiretroviral therapy (ART) has represented a major advancement in the care of people living with HIV (PLWHH), resulting in significant reductions in morbidity and mortality through immune reconstitution and attenuation of homeostatic disruption. Importantly, restoration of immune function in PLWH with opportunistic infections occasionally leads to an intense and uncontrolled cytokine storm following ART initiation known as immune reconstitution inflammatory syndrome (IRIS). IRIS occurrence is associated with the severe and rapid clinical deterioration that results in significant morbidity and mortality. Here, we detail the determinants underlying IRIS development in PLWH, compiling the available knowledge in the field to highlight details of the inflammatory responses in IRIS associated with the most commonly reported opportunistic pathogens. This review also highlights gaps in the understanding of IRIS pathogenesis and summarizes therapeutic strategies that have been used for IRIS.

Effects of time of initiation of antiretroviral therapy in the treatment of patients with HIV/TB co-infection: A systemic review and meta-analysis

This systemic review and meta-analysis aimed to investigate the burden of tuberculosis immune reconstitution syndrome (TB-IRIS) and associated mortality to highlight the importance of future direction in preventing and treatment of TB-IRIS. Randomized clinical trials (RCTs) that compared early antiretroviral therapy (ART) versus late ART were included. PubMed, EMBASE, Science Direct and Cochrane Central Register of Controlled Trials electronic databases were searched. This meta-analysis included 8 RCTs with a total of 4, 425 participants. The result of analysis showed that early initiation of ART was associated with increase in TB-IRIS (RR = 1.83; 95% CI: 1.24-2.70, p = 0.002; I2 = 74%, p = 0.0007) and TB-IRIS associated mortality (RR = 6.05; 95% CI: 1.06-34.59, p = 0.04; I2 = 0%, p = 0.78). Early ART was associated with overall mortality compared with late ART initiation. Grade 3 or 4 adverse events, achieving lower viral load and development of new AIDS-defining illness were not associated with the time of ART initiation. Early ART in HIV/TB co-infected patients resulted conclusive evidence of increased TB-IRIS incidence and TB-IRIS associated mortality. Hence, the finding calls for clinical judgment as to the benefits of initiating ART earlier against the risk of TB-IRIS and associated mortality.

Association of Cytomegalovirus DNA and Immunologic Markers of Cardiovascular Disease

BACKGROUND

Persons living with human immunodeficiency virus (HIV) (PLWH) with high cytomegalovirus (CMV)-specific interferon (IFN) γ response have increased numbers of endothelium homing receptor (CX3CR1)+-expressing cells that are associated with cardiovascular disease. The current study was performed to investigate the effect of cellular levels of CMV DNA on these markers.

METHODS

Eighty paired peripheral blood mononuclear cell samples were collected ≥12 months apart from 40 CMV-seropositive PLWH with suppressed HIV RNA, who started antiretroviral therapy at median of 3-months of infection. The samples were assessed for CMV-specific IFN-γ response by means of enzyme-linked immunospot assay, and participants were classified as low responders (LRs) or high responders (HRs) based on IFN-γ production (≤100 or >100 spot-forming units [SFUs]/105 cells).

RESULTS

Of the 40 participants, 26 (65%) were HRs and 14 (35%) LRs at baseline, which did not change over time or by CMV levels (median at first/second time points, 383/308 SFUs/106 cells for HRs vs 21/41 SFUs/106 for LRs). A decrease in IFN-γ over time was associated with higher CMV DNA levels (P < .01). High CMV response was also associated with increased CD28+CD27-CD4+ T cells expressing CX3CR1 (P < .001). Similarly, increased IFN-γ production was associated with increased CMV-specific CX3CR1+CD28+CD27-CD4+ and CD8+ T cells (P < .001).

CONCLUSIONS

These findings demonstrate that levels of CMV-specific IFN-γ response in PLWH are stable over time, and that HRs have increased circulating T cells expressing CX3CR1 that may put them at increased risk of cardiovascular disease and other inflammatory diseases.

HIV patients, healthy aging and transplant recipients can reveal the hidden footprints of CMV

Cytomegalovirus (CMV) is a β-herpesvirus. Latent infections are common in all populations. However age-associated increases in levels of CMV-reactive antibody are testament to repeated reactivations and periods of viral replication. CMV has been associated with several diseases of aging, including vasculopathy and neurocognitive impairment. These conditions occur at a younger age in persons with particularly high burdens of CMV - transplant recipients and people living with HIV. Here we define the "clinical footprints" as immunopathologies triggered by CMV that develop over many years. A high burden of CMV also drives accumulation of multifunctional terminally-differentiated αβ T-cells, a novel population of Vδ2^- γδ T-cells, and a population of CD56^lo NK cells lacking a key regulatory molecule. An understanding of these "immunological footprints" of CMV may reveal how they collectively promote the "clinical footprints" of the virus. This is explored here in transplant recipients, HIV patients and healthy aging.

Changes in viral hepatitis B screening practices over time in West African HIV clinics

BACKGROUND

We aimed to describe changes in hepatitis B screening practices over a 3-year period among HIV-infected patients in West Africa.

METHODS

A medical chart review was conducted in urban HIV treatment centers in Ivory Coast (3 sites), Benin, Burkina Faso, Senegal, and Togo (1 site each). Among patients who started antiretroviral treatment between 2010 and 2012, 100 per year were randomly selected from each clinic. Demographic, clinical, and laboratory data was collected using a standardized questionnaire. We assessed changes in the proportion of patients screened over time and identified predictors of screening in a multivariable logistic regression.

RESULTS

A total of 2097 patients were included (median age: 37 years, 65.4% of women). Overall, 313 (14.9%) patients had been screened for hepatitis B, with an increase from 10.6% in 2010 to 18.9% in 2012 (P<0.001) and substantial differences across countries. In multivariable analysis, being aged over 45 years (adjusted odds ratio: 1.34 [1.01-1.77]) and having an income-generating activity (adjusted odds ratio: 1.82 [1.09-3.03]) were associated with screening for hepatitis B infection. Overall, 62 HIV-infected patients (19.8%, 95% confidence interval: 15.5-24.7) were HBsAg-positive and 82.3% of them received a tenofovir-containing drug regimen.

CONCLUSION

Hepatitis B screening among HIV-infected patients was low between 2010 and 2012. The increasing availability of HBsAg rapid tests and tenofovir in first-line antiretroviral regimen should improve the rates of hepatitis B screening.

Looking back to move forward: a twenty-year audit of herpes zoster in Asia-Pacific

Background

Herpes zoster (HZ) is a prevalent viral disease that inflicts substantial morbidity and associated healthcare and socioeconomic burdens. Current treatments are not fully effective, especially among the most vulnerable patients. Although widely recommended, vaccination against HZ is not routine; barriers in Asia-Pacific include long-standing neglect of adult immunisation and sparse local data. To address knowledge gaps, raise awareness, and disseminate best practice, we reviewed recent data and guidelines on HZ from the Asia-Pacific region.

Methods

We searched PubMed, Scopus, and World Health Organization databases for articles about HZ published from 1994 to 2014 by authors from Australia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, New Zealand, the Philippines, Singapore, Taiwan, Thailand, and Vietnam. We selected articles about epidemiology, burden, complications, comorbidities, management, prevention, and recommendations/guidelines. Internet searches retrieved additional HZ immunisation guidelines.

Results

From 4007 retrieved articles, we screened-out 1501 duplicates and excluded 1264 extraneous articles, leaving 1242 unique articles. We found guidelines on adult immunisation from Australia, India, Indonesia, Malaysia, New Zealand, the Philippines, South Korea, and Thailand.

HZ epidemiology in Asia-Pacific is similar to elsewhere; incidence rises with age and peaks at around 70 years – lifetime risk is approximately one-third. Average incidence of 3–10/1000 person-years is rising at around 5% per year. The principal risk factors are immunosenescence and immunosuppression. HZ almost always causes pain, and post-herpetic neuralgia is its most common complication. Half or more of hospitalised HZ patients have post-herpetic neuralgia, secondary infections, or inflammatory sequelae that are occasionally fatal. These disease burdens severely diminish patients’ quality of life and incur heavy healthcare utilisation.

Conclusions

Several countries have abundant data on HZ, but others, especially in South-East Asia, very few. However, Asia-Pacific countries generally lack data on HZ vaccine safety, efficacy and cost-effectiveness. Physicians treating HZ and its complications in Asia-Pacific face familiar challenges but, with a vast aged population, Asia bears a unique and growing burden of disease. Given the strong rationale for prevention, most adult immunisation guidelines include HZ vaccine, yet it remains underused. We urge all stakeholders to give higher priority to adult immunisation in general and HZ in particular.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2198-y) contains supplementary material, which is available to authorized users.

Herpes virus reactivation after initiation of interferon-free antiviral agents in HIV-HCV-coinfected subjects: a new immune restoration disease?

We report four HCV-HIV-coinfected patients who developed herpes zoster or muco-cutaneous herpes virus disease shortly after starting interferon-free antiviral treatment for HCV. We suggest that in our patients the prompt clearance of HCV following direct-acting antivirals leads to a paradoxical effect on the innate and adaptive immune system mediating the reactivation of herpetic infection.

A rare case of immune reconstitution inflammatory syndrome presenting as secondary syphilis

Immune reconstitution syndrome has rarely been reported in the context of syphilis infection. We report a patient with AIDS (CD4 42 cells/mm(3), viral load 344,000 cp/ml), treated previously for secondary syphilis and started on an integrase inhibitor-based single-tablet antiretroviral treatment regimen. After four weeks of antiretroviral treatment, he presented with non-tender, non-blanching erythematous nodules on his chest, an elevated rapid plasma reagin (1:1024) and immune reconstitution (CD4 154 cells/mm(3), HIV-RNA 130 cp/ml). A detailed workup to exclude opportunistic infections including secondary and neurosyphilis was performed. The patient was continued on antiretroviral treatment and treated empirically for neurosyphilis given cerebrospinal lymphocytosis and dermatopathology suggesting treponemal antigen-driven B-cell hyperplasia. We favour a diagnosis of immune reconstitution in association with prior syphilis infection attributable to rapid and potent immune restoration afforded by integrase inhibitors.

Patients co-infected with hepatitis C virus (HCV) and human immunodeficiency virus recover genotype cross-reactive neutralising antibodies to HCV during antiretroviral therapy

When severely immunodeficient HIV/HCV co-infected patients are treated with antiretroviral therapy, it is important to know whether HCV-specific antibody responses recover and whether antibody profiles predict the occurrence of HCV-associated immune restoration disease (IRD). In 50 HIV/HCV co-infected patients, we found that antibody reactivity and titres of neutralising antibodies (nAb) to JFH-1 (HCV genotype 2a virus) increased over 48 weeks of therapy. Development of HCV IRD was associated with elevated reactivity to JFH-1 before and during the first 12 weeks of therapy. Individual analyses of HCV IRD and non-HCV IRD patients revealed a lack of an association between nAb responses and HCV viral loads. These results showed that increased HCV-specific antibody levels during therapy were associated with CD4(+) T-cell recovery. Whilst genotype cross-reactive antibody responses may identify co-infected patients at risk of developing HCV IRD, neutralising antibodies to JFH-1 were not involved in suppression of HCV replication during therapy.

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.

Tuberculosis-immune reconstitution inflammatory syndrome in HIV: from pathogenesis to prediction

Tuberculosis-immune reconstitution inflammatory syndrome (TB-IRIS) is an exaggerated, dysregulated immune response against dead or viable antigens of Mycobacterium tuberculosis that frequently occurs after initiation of antiretroviral therapy despite an effective suppression of HIV viremia. Scientific advances in IRIS pathogenesis have led researchers and clinicians to postulate risk factors that could possibly predict this syndrome, in an attempt to reduce the incidence and the severity of IRIS, with appropriate anti-inflammatory therapy. This review is a summary of the available literature on pathogenic mechanisms involved from the macro to the micro level, the clinical spectrum, available predictors and the scope of these biomarkers to function as specific therapeutic targets, that could effectively modulate or ameliorate this syndrome in future.

HIV and co-infections

Despite significant reductions in morbidity and mortality secondary to availability of effective combination anti-retroviral therapy (cART), human immunodeficiency virus (HIV) infection still accounts for 1.5 million deaths annually. The majority of deaths occur in sub-Saharan Africa where rates of opportunistic co-infections are disproportionately high. In this review, we discuss the immunopathogenesis of five common infections that cause significant morbidity in HIV-infected patients globally. These include co-infection with Mycobacterium tuberculosis, Cryptococcus neoformans, hepatitis B virus, hepatitis C virus, and Plasmodium falciparum. Specifically, we review the natural history of each co-infection in the setting of HIV, the specific immune defects induced by HIV, the effects of cART on the immune response to the co-infection, the pathogenesis of immune restoration disease (IRD) associated with each infection, and advances in the areas of prevention of each co-infection via vaccination. Finally, we discuss the opportunities and gaps in knowledge for future research.

Immune reconstitution reactions in human immunodeficiency virus-negative patients: report of a case and review of the literature

BACKGROUND

Immune reconstitution inflammatory syndrome (IRIS) is a phenomenon initially described in patients with human immunodeficiency virus. Upon initiation of combination antiretroviral therapy, recovery of cellular immunity triggers inflammation to a preexisting infection or antigen that causes paradoxical worsening of clinical disease. A similar phenomenon can occur in human immunodeficiency virus-negative patients, including pregnant women, neutropenic hosts, solid-organ or stem cell transplant recipients, and patients receiving tumor necrosis factor inhibitors.

OBSERVATIONS

We report a case of leprosy unmasking and downgrading reaction after stem cell transplantation that highlights some of the challenges inherent to the diagnosis of IRIS, especially in patients without human immunodeficiency virus infection, as well as review the spectrum of previously reported cases of IRIS reactions in this population.

CONCLUSIONS

The mechanism of immune reconstitution reactions is complex and variable, depending on the underlying antigen and the mechanism of immunosuppression or shift in immune status. Use of the term IRIS can aid our recognition of an important phenomenon that occurs in the setting of immunosuppression or shifts in immunity but should not deter us from thinking critically about the distinct processes that underlie this heterogeneous group of conditions.

Risk of Kaposi sarcoma during the first months on combination antiretroviral therapy

OBJECTIVE

To determine whether incident AIDS-defining Kaposi sarcoma or Pneumocystis jiroveci pneumonia (PJP) is associated with combination antiretroviral therapy (cART) initiation.

DESIGN

Compare risk for Kaposi sarcoma and PJP by time on cART and CD4 reconstitution.

METHODS

: In the FHDH-ANRS CO4 cohort (N = 66 369), Kaposi sarcoma (N = 1811) and PJP (N = 1718) incidence rates were computed by demographic and HIV strata. Crude and adjusted relative risk (RR) with 95% confidence intervals (CIs) following cART initiation were calculated by Poisson regression with untreated patients during 1996-2009 as reference. CD4 cell counts were compared by Wilcoxon rank sum tests.

RESULTS

The risk of Kaposi sarcoma was very high during months 1-3 on cART (N = 160, RRCrude 3.94, 95% CI 3.26-4.76), which was incompletely attenuated by adjustment for demographics and contemporaneous CD4 cell count (RRAdj 1.25, 95% CI 1.02-1.53). Corresponding PJP risk was minimally elevated (N = 84, RRCrude 1.80, 95% CI 1.42-2.30) and markedly reduced with adjustment on the same variables and PJP prophylaxis (RRAdj 0.52, CI 0.41-0.67). HIV load had no added effect. Median CD4 cell count at cART initiation was much lower in patients with incident Kaposi sarcoma (82 cells/μl) or PJP (61 cells/μl) within 3 months than in those who did not develop these conditions (>250 cells/μl). Notably, median CD4 cell count change was +44 cells/μl per month with incident Kaposi sarcoma within 3 months of cART initiation versus 0 cells/μl per month with incident PJP (P = 0.0003).

CONCLUSION

Failure of CD4 cell count reconstitution during months 1-3 on cART fully accounted for incident PJP. In contrast, there were 1.6 additional Kaposi sarcoma cases per 1000 person-years during months 1-3 on cART, suggesting that immune reconstitution may contribute to the risk for AIDS-defining Kaposi sarcoma.

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.

Clinical studies with chemokine receptor-5 (CCR5)-inhibitors

PURPOSE OF REVIEW

To summarise recently published clinical studies of chemokine receptor-5 (CCR5)-blockers, including the small-molecule blocker, maraviroc (MVC) and CCR5-monoclonal antibodies for HIV. MVC may have immunomodulating properties through CCR5-blockade. MVC appears well tolerated and penetrates the central nervous system. For these reasons, MVC is being investigated in immunodiscordance, prevention of IRIS and in HCV-HIV co-infection. Novel techniques allow tropism assignment via sequencing of proviral DNA; this testing platform is being utilised in MVC switch studies in those with HIV viraemia below the level of quantification. MVC is being utilised in regimen intensification studies for HIV associated neurocognitive disease.

RECENT FINDINGS

MVC has no anti-inflammatory activity in rheumatoid arthritis. MVC appears well tolerated in hepatitis virus co-infected patients and MVC-intensification in HCV-HIV co-infection suggests a favourable impact on liver fibrosis. Early pilot data suggests MVC intensification may have functional benefit in the CNS. There is a growing body of data on tropism testing using proviral DNA; this technology is being utilised in MVC switch studies. CCR5-monoclonal antibodies administered subcutaneously are promising in Phase II development.

SUMMARY

The place of MVC as an anti-HIV drug in the switch setting and as an immunomodulator is yet to be fully determined.

Short communication: Plasma levels of vitamin D in HIV patients initiating antiretroviral therapy do not predict immune restoration disease associated with Mycobacterium tuberculosis

Immune restoration disease associated with Mycobacterium tuberculosis (TB IRD) is clinically important among HIV patients commencing antiretroviral therapy in countries where tuberculosis is endemic. Vitamin D affects dendritic cell and T cell function and the antimicrobial activity of monocytes. Plasma levels of vitamin D and polymorphisms in the vitamin D receptor may affect tuberculosis, and HIV infection associates with vitamin D deficiency. Here we assess whether plasma vitamin D levels may predict TB IRD. Samples were available from prospective studies of TB IRD in Cambodia (26 cases), India (19 cases), and South Africa (29 cases). IRD cases and controls from each site were similar in age and baseline CD4(+) T cell count. Plasma samples were assessed using 25(OH) vitamin D immunoassay plates. DNA samples were available from a subset of patients and were genotyped for the VDR FokI (F/f) [C/T, rs10735810] SNP. When data from each cohort were pooled to assess ethnic/geographic differences, 25(OH)D levels were higher in Cambodian than Indian or South African patients (p<0.0001) and higher in South African than Indian patients (p<0.0001). TB IRD was not associated with differences in levels of 25(OH)D in any cohort (p=0.36-0.82), irrespective of the patients' prior TB diagnoses/treatment. Carriage of the minor allele of VDR FokI (F/f) was marginally associated with TB IRD in Indian patients (p=0.06) with no association in Cambodians. Neither plasma levels of vitamin D nor the vitamin D allele will usefully predict TB IRD in diverse populations from TB endemic regions.

A fatal case of kaposi sarcoma due to immune reconstitution inflammatory syndrome

The prevalence of AIDS-related Kaposi sarcoma (KS) has markedly declined in the era of highly active antiretroviral therapy (HAART) although it remains one of the most common AIDS-defining malignancies. Although immune reconstitution inflammatory syndrome (IRIS)-related KS (IRIS-KS) represents only a fraction of the IRIS cases, it can be a life-threatening situation. This report describes a fatal case of IRIS-KS. A 32-year-old man with HIV/AIDS was initiated on HAART and experienced rapid immunological and virological response to therapy. He subsequently experienced progressively severe dyspnea and papulonodular skin lesions and was admitted to the hospital with hypoxic respiratory failure. Bronchoscopy revealed numerous friable endobronchial lesions. Histopathology of a skin lesion was consistent with KS. The relatively rapid progression of disease in the setting of improvement in immune function after initiating HAART suggested IRIS-KS. This report reviews previously published cases of IRIS-KS and describes risk factors, immunopathogenesis and treatment options.

Tuberculosis associated immune reconstitution inflammatory syndrome in patients infected with HIV: meningitis a potentially life threatening manifestation

Background

Tuberculosis (TB) is the most common co infection in HIV-infected persons in India, requiring concomitant administration of anti TB and antiretroviral therapies. Paradoxical worsening of tuberculosis after anti-retroviral therapy (ART) initiation is frequently seen.

Objective

To study the frequency, clinical presentation and outcome of paradoxical tuberculosis associated immune reconstitution inflammatory syndrome (TB-IRIS) in HIV infected patients in a TB hospital in North India.

Design

A retrospective chart review of HIV-infected TB patients on anti-tubercular treatment (ATT) at time of ART initiation over a 3 year period. Medical records were reviewed for clinical manifestations and outcome in patients who developed TB-IRIS.

Results

514 HIV-infected patients were enrolled between January 2006 and December 2008. Thirteen (12.6%) of 103 patients who had received ART and ATT simultaneously developed paradoxical TB-IRIS. Clinical presentations of paradoxical TB-IRIS included new lymphadenopathy (n = 3), increase in size of existing lymphadenopathy (n = 3), worsening of existing pulmonary lesions (n = 2), appearance of new pleural effusion (n = 1) and prolonged high grade fever (n = 2). Four patients developed new tubercular meningitis as manifestation of TB-IRIS. Our cases developed TB-IRIS a median of 15 days after starting ART (IQR 15–36). TB-IRIS patients were older (> 35 years) than those with no IRIS (P = 0.03), but were not distinguishable by CD4 T-cell count, duration of ATT before ART or the outcome of TB treatment. Eight (62%) patients had a complete recovery while 5 (38%) patients with TB-IRIS died, of which majority (n = 3) had meningitis.

Conclusions

Paradoxical TB-IRIS is a frequent problem during concomitant ATT and ART in HIV-TB co infected patients in north India. Meningitis is a potentially life threatening manifestation of TB-IRIS.

[Immune reconstitution syndrome]

The immune reconstitution inflammatory syndrome (IRIS) represents a heterogeneous group of conditions. Whilst they typically present in HIV-infected patients with advanced immunodeficiency, IRIS have also been described in HIV-negative patients with immune reconstitution due to other causes of immunosuppression. Frequently IRIS results from an immune response against underlying infection (pathogen-associated IRIS). However, IRIS might become evident during immune reconstitution without an underlying pathogen such as a sarcoid-like illness or an autoimmune thyropathy. Here we report on the epidemiology and risk factors of IRIS along with diagnosis and management of this clinically important inflammatory syndrome.

Assessment of HBV flare in a randomized clinical trial in HIV/HBV coinfected subjects initiating HBV-active antiretroviral therapy in Thailand

Abstract

Clinical Trial number

NCT00192595.

Selective expansion of polyfunctional pathogen-specific CD4(+) T cells in HIV-1-infected patients with immune reconstitution inflammatory syndrome

Since the introduction of highly active antiretroviral therapies (ART), the prognosis for HIV-1 patients has improved immensely. However, approximately 25% of patients can experience a variety of inflammatory symptoms that are collectively known as immune reconstitution inflammatory syndrome (IRIS). Studying the etiology and immunopathology of IRIS has been hampered by the fact that the symptoms and associated opportunistic infections are highly varied. We hypothesized that there is a common mechanism underlying IRIS pathogenesis and investigated a patient group with IRIS related to different pathogens. Functional and phenotypic characterization of PBMC samples was performed by polychromatic flow cytometry after in vitro stimulation with relevant antigenic preparations. In most patients, IRIS events were characterized by the robust increase of preexisting polyfunctional, highly differentiated effector CD4(+) T-cell responses that specifically targeted the antigens of the underlying co-infection. T-cell responses to HIV-1 or other underlying infections were not affected and did not differ between IRIS and non-IRIS patients. These data suggest that patients with IRIS do not have a generalized T-cell dysfunction; instead, IRIS represents a dysregulated CD4(+) T-cell response against residual opportunistic infection antigen. These studies were registered at www.clinical-trials.gov as NCT00557570 and NCT00286767.

Natural killer cell activation distinguishes Mycobacterium tuberculosis-mediated immune reconstitution syndrome from chronic HIV and HIV/MTB coinfection

BACKGROUND

With increased access to antiretroviral treatment (ART), immune reconstitution inflammatory syndrome (IRIS) in Mycobacterium tuberculosis (MTB)-infected populations remains a clinical challenge. We studied a cross-sectional cohort of HIV-infected subjects in Johannesburg (South Africa) to help define the immune correlates that best distinguish IRIS from ongoing MTB cases.

METHODS

We studied HIV+ subjects developing MTB-related unmasking tuberculosis-related immune reconstitution inflammatory syndrome (uTB-IRIS) after ART initiation; control groups were subjects with HIV and HIV/tuberculosis-coinfected subjects with comparable ART treatment. Testing was conducted with whole blood-based 4-color flow cytometry and plasma-based Luminex cytokine assessment.

RESULTS

Natural killer cell activation, C-reactive protein, and interleukin 8 serum concentration were significantly higher in uTB-IRIS subjects compared with both control groups. In addition, all MTB-coinfected subjects, independent of clinical presentation, had higher neutrophils and T-cell activation, together with lower lymphocytes, CD4⁺ T-cell, and myeloid dendritic cell counts. Using conditional inference tree analysis, we show that elevated natural killer cell activation in combination with lymphocyte count characterizes the immunological profile of uTB-IRIS.

CONCLUSION

Our results support a role for innate immune effectors in the immunopathogenesis of unmasking MTB-related IRIS and identify new immune parameters defining this pathology.

Can immune-related genotypes illuminate the immunopathogenesis of cytomegalovirus disease in human immunodeficiency virus-infected patients?

Most human immunodeficiency virus (HIV) patients are seropositive for cytomegalovirus (CMV) but a smaller proportion experience end-organ disease. This observation may reflect variations in genes affecting inflammatory and natural killer cell responses. DNA samples were collected from 240 HIV-infected patients followed at the University Hospitals/Case Medical Center (Cleveland, OH) between 1993 and 2008. Seventy-eight patients (African Americans = 41, Caucasians = 37) experienced CMV disease. Genotypes were determined using allele-specific fluorescent probes or multiplex polymerase chain reaction sequence-specific primers. IL12B3'UTR*(1) and SLC11A1 D543N*(1,2) were associated with CMV disease in African American patients (p = 0.04 and p = 0.02, respectively). IL10-1082*(1,2) and LILRB1 I142T*(1) were associated with CMV disease in Caucasians (p = 0.02 and p = 0.07, respectively). DARC T-46C*(1) and CD14 C-159T*(2) were associated with low nadir CD4(+) T cell counts in African American patients (p = 0.002 and p = 0.01, respectively). Caucasian patients carrying TNFA-308*2, TNFA-1031*(2), IL2-330*(1), CCL2-2518*(2), or LILRB1 I142T*(1) had significantly lower nadir CD4(+) T cells in a bootstrapped multivariable model (p = 0.006-0.02). In general, polymorphisms associated with CMV disease and CD4(+) T cell counts were distinct in Caucasian and African American patients in the United States. The LILRB1 I142T polymorphism was associated with both CMV disease and low nadir CD4(+) T cell counts in Caucasians, but the clearest determinant of low nadir CD4(+) T cell count in African American patients was DARC T-46C.

Mycobacterial antibody levels and immune restoration disease in HIV patients treated in South East Asia

AIM

Immune restoration disease (IRD) associated with Mycobacterium tuberculosis parallels the reconstitution of a pathogen-specific Th1 response. However, it is not clear whether humoral responses to M. tuberculosis antigens also rise, or whether antibody levels predict IRD. Here, humoral immunity to M. tuberculosis antigens was investigated in four Asian cohorts.

METHODS

Plasma samples were obtained from longitudinal prospective studies of HIV patients beginning antiretroviral therapy (ART) in New Delhi (India), Kuala Lumpur (Malaysia), Jakarta (Indonesia) and Phnom Penh (Cambodia). IgG antibodies to purified protein derivative, lipoarabinomannan and 38-kDa antigens of M. tuberculosis were quantitated using in-house ELISAs. IRD was defined as exacerbated symptoms of tuberculosis in patients on anti-tuberculosis therapy or a novel presentation of tuberculosis on ART.

RESULTS

Pre-ART IgG levels to purified protein derivative, lipoarabinomannan and 38-kDa antigen were similar in the IRD and control groups from each site. Compared with non-IRD controls, a higher proportion of IRD patients had elevated IgG levels to lipoarabinomannan (defined as a greater than twofold increase) over 12 weeks of ART. However, this trend was not significant for the other antigens and longitudinal analyses did not reveal clear rises in antibody levels at the time of IRD.

CONCLUSION

Levels of antibody to mycobacterial antigens do not predict IRD, but levels of antibody reactive with lipoarabinomannan rise during an IRD in some patients.

Opportunistic infection-associated immune reconstitution syndrome in transplant recipients

Reversal of pathogen-induced immunosuppression upon employment of effective antimicrobial therapy and withdrawal of iatrogenic immunosuppression has the potential to shift the host immune repertoire towards pathologic inflammatory responses conducive to immune reconstitution syndrome (IRS). Posttransplant IRS has been observed with fungi, M. tuberculosis, cytomegalovirus, and polyoma virus nephropathy. This review discusses the existing state of knowledge regarding IRS and the immune mechanisms that underlie its pathogenesis, with significant implications for developing reliable diagnostic biomarkers and optimal management strategies for post-transplant opportunistic infection-associated IRS.

HCV-specific T-cell responses in HIV/hepatitis C virus-coinfected patients on highly active antiretroviral therapy are comparable to those observed in hepatitis C virus-monoinfected individuals

BACKGROUND

Cellular responses against hepatitis C virus (HCV) are impaired in HIV/HCV-coinfected patients showing uncontrolled viral replication and immune suppression. Very few studies have explored to what extent HCV-specific response improves as a consequence of control of HIV replication by highly active antiretroviral therapy. We compared HCV-specific T-cell responses between HIV/HCV-coinfected patients, showing complete viral suppression, and HCV-monoinfected patients.

METHODS

HCV-specific T-cell responses were examined in 50 interferon-naive patients with chronic hepatitis C: 27 HCV-mono-infected and 23 HIV/HCV-coinfected on highly active antiretroviral therapy and undetectable HIV load. Production of interferon-γ and tumor necrosis factor-α was simultaneously measured in response to genotype-matched overlapping peptides spanning the whole HCV proteome by flow cytometry. Differences between groups were tested using nonparametric tests.

RESULTS

More than half of patients presented CD4+ (60%) or CD8+ (57%) response to at least one HCV protein with no significant differences between both groups. Intensity and breadth of response were also similar between groups. The functional profile of response was represented, in both groups, mainly by monofunctional subsets, although there were some differences between CD4+ and CD8+ T-cell response. CD8+ response was mediated almost exclusively by monofunctional interferon-γ+ cells, whereas bifunctional interferon-γ+ tumor necrosis factor-α+ cells showed a moderate contribution to CD4+ response. Most of the CD8+ response was mediated by interferon-γ, whereas tumor necrosis factor-α was the highest contributor to CD4+ response.

CONCLUSIONS

Our study demonstrates that in HIV/HCV-coinfected patients with maximal HIV suppression under highly active antiretroviral therapy, several characteristics of anti-HCV T-cell response are similar to those found in HCV-monoinfected patients, suggesting that control of HIV replication might improve HCV-specific T-cell response in HIV/HCV-coinfected patients.

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.

TLR2-induced cytokine responses may characterize HIV-infected patients experiencing mycobacterial immune restoration disease

OBJECTIVES

Most HIV patients who experience Mycobacterium tuberculosis-associated immune restoration disease (TB IRD) display elevated interferon-gamma (IFNγ) responses against mycobacterial antigens, but these can occur without an IRD. Recognition of mycobacteria-associated molecular patterns through toll-like receptors (TLRs) on dendritic cells and monocytes induces cytokine production. Here, we investigate TLR-induced responses in IRD.

DESIGN

Peripheral blood mononuclear cells (PBMCs) were collected at approximately weeks 0, 6, 12, 24 and 48 after antiretroviral therapy from five patients experiencing TB IRD, nine matched non-IRD patients and 15 healthy controls.

METHODS

IFNγ production by PBMC stimulated with protein purified derivative (PPD) was assessed by ELISpot. TLR2 expression on myeloid dendritic cells (mDCs) and monocytes was assessed by flow cytometry. TNFα, IL-12p40 and IL-10 were measured by ELISA in 24-h cultures of PBMC with lipomannan (mycobacteria-derived TLR2 agonist).

RESULTS

TLR2 expression on mDC and monocytes was higher in patients than controls at baseline (P < 0.005). TLR2 expression decreased to normal levels on mDC by week 12, but remained higher on monocytes at week 24 (P = 0.02). At week 24, IRD patients showed higher IFNγ responses to PPD (P = 0.02), TLR2 expression on monocytes (P = 0.006) and lipomannan-induced TNFα production (P = 0.016) than non-IRD patients. Lipomannan-induced TNFα and IL-12p40 responses paralleled TB IRD in the patients with high TLR2 expression. IL-10 levels did not associate with IRD.

CONCLUSION

TLR2-induced pro-inflammatory cytokines by dendritic cells or monocytes may contribute to the pathogenesis of mycobacterial IRD.

HIV/HCV co-infection: pathogenesis, clinical complications, treatment, and new therapeutic technologies

World-wide, hepatitis C virus (HCV) accounts for approximately 130 million chronic infections, with an overall 3% prevalence. Four to 5 million persons are co-infected with HIV. It is well established that HIV has a negative impact on the natural history of HCV, including a higher rate of viral persistence, increased viral load, and more rapid progression to fibrosis, end-stage liver disease, and death. Whether HCV has a negative impact on HIV disease progression continues to be debated. However, following the introduction of effective combination antiretroviral therapy, the survival of coinfected individuals has significantly improved and HCV-associated diseases have emerged as the most important co-morbidities. In this review, we summarize the newest studies regarding the pathogenesis of HIV/HCV coinfection, including effects of coinfection on HIV disease progression, HCV-associated liver disease, the immune system, kidney and cardiovascular disease, and neurologic status; and effectiveness of current anti-HIV and HCV therapies and proposed new treatment strategies.

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.

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.

Potential role of statins for the management of immune reconstitution syndrome

It has become evident that while a robust inflammatory response plays a critical role in eradicating invading microbes, dysregulated immunity can be detrimental to the host if an optimal balance between the inflammatory and anti-inflammatory reactions is disrupted. Opportunistic infection-associated immune reconstitution syndrome is characterized by an aggressive inflammatory immune response and its management remains challenging and largely unknown. Statins, in addition to their lipid lower effects have anti-inflammatory attributes and there is precedence for the use of these agents as a therapeutic modality for autoimmune inflammatory disorders which have similar underlying pathogenesis as immune reconstitution syndrome. We hypothesize that statins may have a potential role for the management of immune reconstitution syndrome. Our proposal has biologic and translational implications for optimizing outcomes in patients with immune reconstitution syndrome.

Multi-analyte profiling of ten cytokines in South African HIV-infected patients with Immune Reconstitution Inflammatory Syndrome (IRIS)

Background

Immune reconstitution inflammatory syndrome (IRIS) is an important complication of HAART in sub-Saharan Africa, where opportunistic infections (OIs) including mycobacteria and cryptococcus are common. The immune system's role in HIV infected patients is complex with cytokine expression strongly influencing HIV infection and replication.

Methods

We determined the expression patterns of 10 cytokines by Luminex multi-analyte profiling in 17 IRIS nested case-control pairs participating in a prospective South African cohort initiating anti-retroviral therapy.

Results

Interferon-gamma (IFN-γ) expression was significantly elevated in IRIS cases compared to controls (median 9.88 pg/ml versus 2.68 pg/ml, respectively, P = 0.0057), while other cytokines displayed non-significant differences in expression. Significant correlation was observed between IL-6, IL-10, and IFN-γ expression in the IRIS patients.

Conclusions

Significantly increased expression levels of IFN-γ suggest that this cytokine possibly plays a role in IRIS pathology and is a potential diagnostic marker.

Can immunogenetics illuminate the diverse manifestations of respiratory infections?

Improved technologies for high-throughput genotyping and the establishment of well-defined cohorts prompted hope that polymorphisms would be discovered that define a patients' risk of respiratory disease or aid in diagnosis. Genetic pitfalls encountered in this quest include genotyping errors, ethnic differences and linkage dysequilibrium. Differences in the definition of the disease phenotype also create discrepancies, so immunogenetic testing has not yet reached the clinic. However, associations between a polymorphism and a disease phenotype place the gene or one in linkage dysequilibrium on the path to the disease. Here we review studies of immune-related genes that are illuminating the immunopathogenesis of community-acquired pneumonia and mycobacterial infections.

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.