Immune dysfunction and immune restoration disease in HIV patients given highly active antiretroviral therapy

CD4+ T cell count and HIV-1 viral load dynamics positively impacted by H. pylori infection in HIV-positive patients regardless of ART status in a high-burden setting

BACKGROUND

There is a widespread co-infection of HIV and Helicobacter pylori (H. pylori) globally, particularly in developing countries, and it has been suggested that this co-infection may affect the course of HIV disease. However, the interplay between H. pylori infection and HIV disease progression is not fully elucidated. In this study, we investigated the effect of H. pylori co-infection on CD4+ T cell count and HIV viral load dynamics in HIV-positive individuals in a high co-endemic setting.

METHODS

A comparative cross-sectional study was conducted among 288 HIV-positive and 175 HIV-negative individuals, both with and without H. pylori infection. Among HIV-positive participants, 195 were on antiretroviral therapy (ART) and 93 were ART-naïve. CD4+ T cell count and HIV-1 viral load were measured and compared between H. pylori-infected and -uninfected individuals, taking into account different HIV and ART status.

RESULT

Our study demonstrated that individuals infected with H. pylori had a significantly higher CD4+ T cell count compared to uninfected controls among both HIV-negative and HIV-positive participants, regardless of ART therapy. Conversely, HIV/H. pylori co-infected participants had lower HIV-1 viral load than those without H. pylori infection. Linear regression analysis further confirmed a positive association between H. pylori infection, along with other clinical factors such as BMI, ART, and duration of therapy, with CD4+ T cell count while indicating an inverse relationship with HIV-1 viral load in HIV-positive patients. Additionally, factors such as khat chewing, age and WHO clinical stage of HIV were associated with reduced CD4+ T cell count and increased HIV-1 viral load.

CONCLUSION

Our study demonstrates that H. pylori co-infection was associated with higher CD4+ T cell count and lower HIV-1 viral load in HIV-positive patients, regardless of ART status. These findings show a positive effect of H. pylori co-infection on the dynamics of HIV-related immunological and virological parameters. Further studies are needed to elucidate the underlying mechanisms of the observed effects.

Differences in epigenetic age by HIV status among patients with a non-AIDS defining cancer

OBJECTIVE

People with HIV (PWH) are living longer and experiencing higher numbers of non-AIDS-defining cancers (NADC). Epigenetic aging biomarkers have been linked to cancer risk, and cancer is now a leading cause of death in PWH, but these biomarkers have not been investigated in PWH and cancer.

DESIGN

In order to compare epigenetic age by HIV status, HIV-uninfected participants were matched to PWH by reported age, tumor site, tumor sequence number, and cancer treatment status.

METHODS

DNA from blood was assayed using Illumina MethylationEPIC BeadChip, and we estimated immune cell composition and aging from three epigenetic clocks: Horvath, GrimAge, and epiTOC2. Age acceleration by clock was computed as the residual from the expected value, calculated using linear regression, for each study participant. Comparisons across HIV status used the Wilcoxon rank sum test. Hazard ratios and 95% confidence intervals for the association between age acceleration and survival in PWH were estimated with Cox regression.

RESULTS

Among 65 NADC participants with HIV and 64 without, biological age from epiTOC2 ( P  < 0.0001) and GrimAge ( P  = 0.017) was significantly higher in PWH. Biological age acceleration was significantly higher in PWH using epiTOC2 ( P  < 0.01) and GrimAge ( P  < 0.0001), with the difference in GrimAge remaining statistically significant after adjustment for immune cell composition. Among PWH, GrimAge acceleration was significantly associated with increased risk of death (hazard ratio 1.11; 95% confidence interval (CI) 1.04-1.18).

CONCLUSION

We observed a higher epigenetic age in PWH with a NADC diagnosis compared with their HIV-uninfected counterparts, as well as a significant association between this accelerated biological aging and survival for patients diagnosed with a NADC.

Non-infectious Uveitis as a Manifestation of the Immune Reconstitution Inflammatory Syndrome in Patients Infected by HIV

OBJECTIVE

To describe a retrospective review of HIV patients with noninfectious uveitis. Data collected included: demographics, anatomic classification and phenotypic diagnosis of the uveitis, systemic immune-mediated disorders (IMD), time from HIV diagnosis to uveitis, CD4 count, viral load, treatment and complications of treatment and time of follow-up.

RESULTS

Twenty patients (18 males) were included. The time lag between HIV diagnosis and the onset of uveitis was 9 ± 8.5 years. Mean CD4 count was 670 ± 294 cells/ml. Viral load was undetectable in 14 out of 18 cases. In 6 patients IMD was diagnosed prior to or concurring with the uveitis diagnosis. The use of immunosuppressive therapies was necessary in 6 patients (including biologics in 4 cases). The mean follow-up was 42.2 months.

CONCLUSIONS

noninfectious uveitis could be the first manifestation of IMD in patients with well-controlled HIV infection. Immunosuppression appeared to be a safe therapeutic option in our cohort of patients.

Candida spp. co-infection in COVID-19 patients with severe pneumonia: Prevalence study and associated risk factors

Background

Invasive fungal infections (IFI) are increasing in prevalence in recent years. In the last few months, the rise of COVID-19 patients has generated a new escalation in patients presenting opportunistic mycoses, mainly by Aspergillus. Candida infections are not being reported yet.

Objectives

We aimed to determine the prevalence of systemic candidiasis in patients admitted to ICUs due to severe pneumonia secondary to SARS-CoV-2 infection and the existence of possible associated risk factors that led these patients to develop candidiasis.

Patients/methods

We designed a study including patients with a confirmed diagnosis of COVID-19.

Results

The prevalence of systemic candidiasis was 14.4%, and the main isolated species were C. albicans and C. parapsilosis. All patients that were tested positive for Candida spp. stayed longer in the ICU in comparison to patients who tested negative. Patients with candidiasis had higher MuLBSTA score and mortality rates and a worse radiological involvement. In our study, Candida spp. isolates were found in patients that were submitted to: tocilizumab, tocilizumab plus systemic steroids, interferon type 1β and Lopinavir-Ritonavir.

Conclusions

Results suggested a high prevalence of systemic candidiasis in severe COVID-19-associated pneumonia patients. Patients with Candidiasis had the worst clinical outcomes. Treatment with tocilizumab could potentialize the risk to develop systemic candidiasis.

Lack of elevated pre-ART elastase-ANCA levels in patients developing TB-IRIS

Background

Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) in HIV-TB co-infected patients receiving antiretroviral therapy (ART) has been linked to neutrophil activation. Anti-neutrophil cytoplasmic antibodies (ANCAs) are also associated with neutrophil activation. Since ANCAs are reportedly skewed in TB and HIV infections, we investigated plasma levels of 7 ANCAs in TB-IRIS patients.

Methods

We retrospectively compared 17 HIV-TB patients who developed TB-IRIS with controls of similar CD4 count, age and gender who did not (HIV⁺TB⁺ n = 17), HIV-infected patients without TB (HIV⁺TB^-, n = 17) and 10 HIV-negative (HIV^-TB^-) controls. Frozen plasma was collected before ART, at 3 and 9 months of ART, and examined by ELISA for levels of 7 ANCAs directed against; Proteinase 3 (PR3), Myeloperoxidase (MPO), Permeability-increasing protein (BPI), Elastase, Cathepsin, Lysozyme, and Lactoferrin.

Results

Compared to HIV⁺TB⁺ controls, pre-ART anti-elastase levels were lower in TB-IRIS patients (p = 0.026) and HIV^-TB^- controls (p = 0.044), whereas other ANCAs did not show significant differences between groups at any time point. A significant decrease over time could be observed in TB-IRIS patients during ART for anti -PR3 (p = 0.027), -lysozyme (p = 0.011), and -lactoferrin (p = 0.019). Conversely, HIV⁺TB⁺ controls showed a significant decrease over time for anti -MPO (p = 0.002), -lyzosyme (p = 0.002) and -elastase (p < 0.001).

Conclusion

The lack of elevated anti-elastase levels in TB-IRIS patients as opposed to HIV⁺TB⁺ controls correspond to previous findings of lowered immune capacity in patients that will develop TB-IRIS. This may suggest a specific role for anti-elastase, elastase or even matrix-metalloproteinases in TB-IRIS. The precise dynamics of neutrophil activation in HIV-TB merits further investigation and could provide more insight in the early mechanisms leading up to TB-IRIS.

CNS immune reconstitution inflammatory syndrome

Immune reconstitution inflammatory syndrome (IRIS) describes a syndrome of aberrant reconstituted immunity, often in association with HIV infection, beginning with a normalization of CD4+ T-cell counts resulting in a dysregulated immune response against an infecting opportunistic pathogen and the host. In this chapter, we discuss the unique nature of IRIS when present in the central nervous system (CNS IRIS) and the changes experienced with each host pathogen and its unique influence on the immune system. Consensus on the mechanism of action of the immune system in IRIS pathology is less clear and multiple theories have been proposed. Here we explore the early history of the term IRIS, proposed mechanisms and animal models, as well as common CNS pathogens associated with IRIS, and management strategies.

TB-IRIS: Proteomic analysis of in vitro PBMC responses to Mycobacterium tuberculosis and response modulation by dexamethasone

Paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) occurs in 8-54% of South African patients undergoing treatment for tuberculosis/human immunodeficiency virus co-infection. Improved TB-IRIS molecular pathogenesis understanding would enhance risk stratification, diagnosis, prognostication, and treatment. We assessed how TB-IRIS status and dexamethasone influence leukocyte proteomic responses to Mycobacterium tuberculosis (Mtb). Patient blood was obtained three weeks post-anti-retroviral therapy initiation. Isolated mononuclear cells were stimulated ex vivo with heat-killed Mtb in the presence/absence of dexamethasone. Mass spectrometry-based proteomic comparison of TB-IRIS and non-IRIS patient-derived cells facilitated generation of hypotheses regarding pathogenesis. Few represented TB-IRIS-group immune-related pathways achieved significant activation, with relative under-utilisation of "inter-cellular interaction" and "Fcγ receptor-mediated phagocytosis" (but a tendency towards apoptosis-related) pathways. Dexamethasone facilitated significant activation of innate-related pathways. Differentially-expressed non-IRIS-group proteins suggest focused and co-ordinated immunological pathways, regardless of dexamethasone status. Findings suggest a relative deficit in TB-IRIS-group responses to and clearance of Mtb antigens, ameliorated by dexamethasone.

A rare occurrence of epidermolysis bullosa acquisita in a patient with retroviral disease

Epidermolysis bullosa acquisita is a chronic subepidermal blistering disease associated with autoimmunity to type-VII collagen within anchoring fibrils located at the dermo-epidermal junction. This entity is rarely reported from India. It can have a variety of presentations. Its occurrence with retroviral disease has rarely been reported. Here, we present a case of epidermolysis bullosa acquisita in a patient with HIV infection.

HIV-1 Evolutionary Patterns Associated with Metastatic Kaposi's Sarcoma during AIDS

Kaposi's sarcoma (KS) in HIV-infected individuals can have a wide range of clinical outcomes, from indolent skin tumors to a life-threatening visceral cancer. KS tumors contain endothelial-related cells and inflammatory cells that may be HIV-infected. In this study we tested if HIV evolutionary patterns distinguish KS tumor relatedness and progression. Multisite autopsies from participants who died from HIV-AIDS with KS prior to the availability of antiretroviral therapy were identified at the AIDS and Cancer Specimen Resource (ACSR). Two patients (KS1 and KS2) died predominantly from non-KS-associated disease and KS3 died due to aggressive and metastatic KS within one month of diagnosis. Skin and visceral tumor and nontumor autopsy tissues were obtained (n = 12). Single genome sequencing was used to amplify HIV RNA and DNA, which was present in all tumors. Independent HIV tumor clades in phylogenies differentiated KS1 and KS2 from KS3, whose sequences were interrelated by both phylogeny and selection. HIV compartmentalization was confirmed in KS1 and KS2 tumors; however, in KS3, no compartmentalization was observed among sampled tissues. While the sample size is small, the HIV evolutionary patterns observed in all patients suggest an interplay between tumor cells and HIV-infected cells which provides a selective advantage and could promote KS progression.

HLA Immunogenotype Determines Persistent Human Papillomavirus Virus Infection in HIV-Infected Patients Receiving Antiretroviral Treatment

A proportion of human immunodeficiency virus (HIV)-infected patients develop persistent, stigmatizing human papillomavirus (HPV)-related cutaneous and genital warts and anogenital (pre)cancer. This is the first study to investigate immunogenetic variations that might account for HPV susceptibility and the largest to date to categorize the HPV types associated with cutaneous warts in HIV-positive patients. The HLA class I and II allele distribution was analyzed in 49 antiretroviral (ART)-treated HIV-positive patients with persistent warts, 42 noninfected controls, and 46 HIV-positive controls. The allele HLA-B*44 was more frequently identified in HIV-positive patients with warts (P = .004); a susceptible haplotype (HLA-B*44, HLA-C*05; P = .001) and protective genes (HLA-DQB1*06; P = .03) may also contribute. Cutaneous wart biopsy specimens from HIV-positive patients harbored common wart types HPV27/57, the unusual wart type HPV7, and an excess of Betapapillomavirus types (P = .002), compared with wart specimens from noninfected controls. These findings suggest that HLA testing might assist in stratifying those patients in whom vaccination should be recommended.

Opportunistic infections and immune reconstitution inflammatory syndrome in HIV-1-infected adults in the combined antiretroviral therapy era: a comprehensive review

Despite the availability of effective combined antiretroviral treatment, many patients still present with advanced HIV infection, often accompanied by an AIDS-defining disease. A subgroup of patients starting antiretroviral treatment under these clinical conditions may experience paradoxical worsening of their disease as a result of an exaggerated immune response towards an active (but also subclinical) infectious agent, despite an appropriate virological and immunological response to the treatment. This clinical condition, known as immune reconstitution inflammatory syndrome, may cause significant morbidity and even mortality if it is not promptly recognized and treated. This review updates current knowledge about the incidence, diagnostic criteria, risk factors, clinical manifestations, and management of opportunistic infections and immune reconstitution inflammatory syndrome in the combined antiretroviral treatment era.

Evaluation of thyroid function and autoimmunity in HIV-infected women

Autoimmune thyroid diseases (AITD) are the main causes of thyroid dysfunction and the most common autoimmune diseases in the world. An association between AITD and infections with the human immunodeficiency virus (HIV), in combination with the effects of highly active anti-retroviral therapy (HAART), has been suggested by several research groups. The aim of the present study was to evaluate the frequency of thyroid dysfunction and AITD in women > 35 years of age infected with HIV, and to identify factors associated with the emergence of these thyroid abnormalities. HIV-infected women (n = 153) selected from the infectious disease outpatient clinic at a University Hospital in Rio de Janeiro were characterized based on their circulating CD4+ lymphocytes levels, viral loads, serum TSH levels, and the presence of FT4 and anti-thyroperoxidase antibodies (TPO-Ab). A total of 129 participants were on HAART and 24 were not. The frequency of thyroid disorders was 7.8% (12/153 patients) and all were on HAART at the time of diagnosis, yielding a prevalence of 9.3% in patients receiving HAART compared with 0% in patients not on HAART. AITD, hyper, and hypothyroidism were detected in 4.6%, 3.1%, and 4.1% of HAART patients. It was not detected any thyroid dysfunction or autoimmunity in HIV-infected women not on HAART. This study demonstrated an association between HAART and the development of AITD. In addition AITD only developed in HAART patients also presenting with undetectable viral loads and slightly elevated CD4+ T cell counts.

A non-synonymous polymorphism in IL-23R Gene (rs1884444) is associated with reduced risk to schistosomiasis-associated Immune Reconstitution Inflammatory Syndrome in a Kenyan population

Background

Human Immunodeficiency Virus (HIV) and Schistosomiasis co-infection is common among residents at the shores of Lake Victoria in Kenya. About 36% of this population initiating antiretroviral therapy (ART) experience Immune Reconstitution Inflammatory Syndrome (IRIS) that complicates recovery. Several IL-23R alleles have been associated with susceptibility to both autoimmune and inflammatory diseases through T-helper type 17 (TH₁₇) cells. However, whether or not variants within the IL-23R increase susceptibility to IRIS in western Kenya is unknown. The objective of the current study was to determine the association between IL-23R gene polymorphisms, CD4+ cell counts and HIV RNA levels and IRIS in HIV and Schistosoma mansoni co-infected patients undergoing highly active anti-retroviral therapy (HAART).

Methods

A three-month case–control study was conducted on antiretroviral naïve schistosomiasis/HIV co-infected fishermen starting HAART in Uyoma Rarieda, Siaya County, Kenya. Seventy one patients were sampled at baseline and followed up for three months, to establish if they developed Schistosoma-related IRIS. In addition, the CD4+ cell counts and HIV RNA levels were determined in pre- and post-administration of HAART. Variations at five polymorphic sites of IL-23R (rs1884444, rs11465754, rs6682925, rs7530511 and rs7539625) based on >10% minor allele frequency in Yoruban reference population was determined using Allelic Discrimination Assay. The association between the five variants and susceptibility to IRIS was determined using logistic regression while controlling for potential confounders. In addition, the functional differences between the baseline CD4 + Cell counts and viral loads were determined using medians while across IL-23R genotypes were determined using Kruskal-Wallis tests.

Results

Overall, 26 (36.6%) patients developed schistosomiasis-associated IRIS at a median age of 35.5 years. Carriage of the TT genotype at the non-synonymous rs1884444 T > G relative to GG, was associated with a decreased risk of schistosomiasis-associated IRIS (OR, 0.25, 95% CI, 0.07-0.96, P = 0.043) while both baseline CD4+ cell counts and viral loads had no association with IRIS.

Conclusion

These findings indicate that the non-synonymous variant rs1884444 T > G of IL-23R is associated with a decreased risk to schistosomiasis-associated IRIS. However, additional studies in a larger cohort and with an all inclusive polymorphic variants in the synonymous and non-synonymous regions need to be evaluated.

Matrix metalloproteinases and tissue damage in HIV-tuberculosis immune reconstitution inflammatory syndrome

The HIV-TB-associated immune reconstitution inflammatory syndrome (TB-IRIS) can complicate combined treatments for HIV-1 and TB. Little is known about tissue damage in TB-IRIS. Matrix metalloproteinases (MMPs) degrade components of the extracellular matrix and consequently may play a role in such immunopathology. Here we investigated the involvement of MMPs in TB-IRIS. We determined MMP transcript abundance and secreted protein in Mycobacterium tuberculosis stimulated PBMCs from 22 TB-IRIS patients and 22 non-IRIS controls. We also measured MMP protein levels in corresponding serum and the effect of prednisone--which reduces the duration of symptoms in IRIS patients--or placebo treatment on MMP transcript and circulating MMP protein levels. PBMCs from TB-IRIS had increased MMP-1, -3, -7, and -10 transcript levels when compared with those of controls at either 6 or 24 h. Similarly, MMP-1, -3, -7, and -10 protein secretion in stimulated cultures was higher in TB-IRIS than in controls. Serum MMP-7 concentration was elevated in TB-IRIS and 2 weeks of corticosteroid therapy decreased this level, although not significantly. TB-IRIS is associated with a distinct pattern of MMP gene and protein activation. Modulation of dysregulated MMP activity may represent a novel therapeutic approach to alleviate TB-IRIS in HIV-TB patients undergoing treatment.

Role of IL-6 in Mycobacterium avium--associated immune reconstitution inflammatory syndrome

Immune reconstitution inflammatory syndrome (IRIS) is a major adverse event of antiretroviral therapy in HIV infection, and paradoxically occurs as HIV viremia is suppressed and CD4 T cell numbers recover. IRIS reflects pathogenic immune responses against opportunistic infections acquired during the period of immunodeficiency, but little is understood about the mechanisms of inflammatory pathology. In this study, we show that IL-6 and C-reactive protein levels transiently rise at the time of the IRIS event in HIV-infected patients, unmasking Mycobacterium avium complex infection after starting antiretroviral therapy. To directly test the role of IL-6 in IRIS pathology, we used a model of experimentally inducible IRIS in which M. avium-infected T cell-deficient mice undergo a fatal inflammatory disease after reconstitution with CD4 T cells. We find that IL-6 neutralization reduces C-reactive protein levels, alleviates wasting disease, and extends host survival during experimental IRIS. Moreover, we show that combined blockade of IL-6 and IFN-γ further reduces IRIS pathology, even after the onset of wasting disease. The combination of these clinical and experimental-model data show that the IL-6 pathway is not only a biomarker of mycobacterial IRIS but also a major mediator of pathology distinct from IFN-γ and may be a useful target for therapeutic intervention.

Chronic HIV infection enhances the responsiveness of antigen presenting cells to commensal Lactobacillus

Chronic immune activation despite long-term therapy poses an obstacle to immune recovery in HIV infection. The role of antigen presenting cells (APCs) in chronic immune activation during HIV infection remains to be fully determined. APCs, the frontline of immune defense against pathogens, are capable of distinguishing between pathogens and non-pathogenic, commensal bacteria. We hypothesized that HIV infection induces dysfunction in APC immune recognition and response to some commensal bacteria and that this may promote chronic immune activation. Therefore we examined APC inflammatory cytokine responses to commensal lactobacilli. We found that APCs from HIV-infected patients produced an enhanced inflammatory response to Lactobacillus plantarum WCFS1 as compared to APCs from healthy, HIV-negative controls. Increased APC expression of TLR2 and CD36, signaling through p38-MAPK, and decreased expression of MAP kinase phosphatase-1 (MKP-1) in HIV infection was associated with this heightened immune response. Our findings suggest that chronic HIV infection enhances the responsiveness of APCs to commensal lactobacilli, a mechanism that may partly contribute to chronic immune activation.

Short communication: CD4 cell count increases during successful treatment of Graves' disease with methimazole in HIV-infected patients on antiretroviral therapy

With the increased survival of HIV-infected patients receiving antiretroviral therapy (ART), unexpected complications due to the untoward effect of antiretroviral agents or immunologic changes have been observed. Here, we report two cases of Graves' disease (GD) presenting with classic symptoms of hyperthyroidism occurring 44 and 47 months after ART initiation. Both patients had severe immune suppression prior to ART initiation (CD4 cell count≤50 cells/μL), with an increase on CD4 cell count to 354 and 329 cells/μL, respectively, at the time of GD diagnosis. Administration of methimazole (MMI) resulted in dramatic improvements in symptoms and thyroid function. In addition, CD4 cell count unexpectedly increased to >500 cells/μL within three months on MMI. Hyperthyroidism caused by GD has been increasingly reported following the initiation of ART and may be related to immune reconstitution. The mechanisms underlying the increases in CD4 cell count after successful treatment of GD with MMI require further investigation, but may be due to improved immune recovery with the correction of hyperthyroidism or a specific effect of MMI on immune function.

The effect of human immunodeficiency virus-1 on monocyte-derived dendritic cell maturation and function

Dendritic cells (DC) are mediators of the adaptive immune response responsible for antigen presentation to naive T cells in secondary lymph organs. Human immunodeficiency virus (HIV-1) has been reported to inhibit the maturation of DC, but a clear link between maturation and function has not been elucidated. To understand further the effects of HIV-1 on DC maturation and function, we expanded upon previous investigations and assessed the effects of HIV-1 infection on the expression of surface molecules, carbohydrate endocytosis, antigen presentation and lipopolysaccharide (LPS) responsiveness over the course of maturation. In vitro infection with HIV-1 resulted in an increase in the expression of DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) as well as decreases in maturation-induced CCR7 and major histocompatibility complex (MHC)-II expression. Retention of endocytosis that normally occurs with DC maturation as well as inhibition of antigen presentation to CD8(+) T cells was also observed. Mitogen-activated protein kinase (MAPK) responsiveness to LPS as measured by phosphorylation of p38, c-Jun N-terminal kinase (JNK) and extracellular-regulated kinase (ERK)1/2 was not affected by HIV-1 infection. In summary, in-vitro HIV-1 impairs DC maturation, as defined by cell surface protein expression, with selective alterations in mature DC function. Understanding the mechanisms of DC dysfunction in HIV infection will provide further insight into HIV immune pathogenesis.

The immune reconstitution inflammatory syndrome

A paradoxical clinical worsening of a known condition or the appearance of a new condition after initiating antiretroviral therapy in HIV-infected patients is defined as immune reconstitution inflammatory syndrome (IRIS). Because of wide variation in clinical presentation and the still increasing spectrum of symptoms and etiologies reported, diagnosis remains problematic. Furthermore, no test is currently available to establish an IRIS diagnosis. Until a greater understanding of the syndrome is achieved in different regions of the world, clinicians need to remain vigilant when initiating ART and individualize therapy according to known treatment options for the specific infectious agent.

Pathogenesis of the immune reconstitution inflammatory syndrome in HIV-infected patients

PURPOSE OF REVIEW

The immune reconstitution inflammatory syndrome (IRIS) is an important clinical complication in HIV-infected patients initiating antiretroviral therapy. This review focuses on the latest literature pertaining to the pathogenesis of IRIS.

RECENT FINDINGS

The clinical manifestations of IRIS are heterogeneous due to the variety of opportunistic infections that are associated with this inflammatory syndrome. However, the disproportionate inflammation is a defining hallmark for which common mechanisms are suspected. Lymphopenia-induced proliferation in the context of systemic immune activation, presence of high antigenic exposure and a wider availability of interleukin-7 contribute to the exacerbated immune response underlying IRIS. Defect in pathogen clearance by phagocytes might favor high pathogen burden, which in turn is thought to activate both innate immune cells and pathogen-specific T cells upon correction of the CD4 T-cell lymphopenia, predisposing to IRIS. This common scenario might be further invigorated by functional impairments among regulatory T cells.

SUMMARY

Further insight into the cellular mechanisms driving IRIS is urgently needed. Understanding the relative contribution of distinct effector and regulatory T-cell subsets, and innate immune components to IRIS is required to inspire future therapeutic approaches.

Immune reconstitution inflammatory syndrome manifesting as development of multiple autoimmune disorders and skin cancer progression

We report the case of a 56-year-old man with the rare autoimmune pathologies of alternating hypothyroidism and hyperthyroidism due to thyroid-stimulating hormone receptor antibodies, and rheumatoid arthritis as manifestations of a human immunodeficiency virus-related immune reconstitution inflammatory syndrome. The patient also developed overt progression of a pre-existing skin malignancy that may also be related. This case highlights immune reconstitution syndrome as an important differential diagnosis following antiretroviral therapy commencement, and that a high index of suspicion should be maintained for this rare but important cluster of conditions. Furthermore, the patient's genetic predisposition to autoimmunity provides helpful insights into the pathogenesis of these disorders.

HIV-1 matrix protein p17 binds to the IL-8 receptor CXCR1 and shows IL-8–like chemokine activity on monocytes through Rho/ROCK activation

Exogenous HIV-1 matrix protein p17 was found to deregulate biologic activities of many different immune cells that are directly or indirectly involved in AIDS pathogenesis after binding to unknown cellular receptor(s). In particular, p17 was found to induce a functional program in monocytes related to activation and inflammation. In the present study, we demonstrate that CXCR1 is the receptor molecule responsible for p17 chemokine–like activity on monocytes. After CXCR1 binding, p17 was capable of triggering rapid adhesion and chemotaxis of monocytes through a pathway that involved Rho/ROCK. Moreover, CXCR1-silenced primary monocytes lost responsiveness to p17 chemoattraction, whereas CXCR1-transfected Jurkat cells acquired responsiveness. Surface plasmon resonance studies confirmed the capacity of p17 to bind CXCR1 and showed that the p17/CXCR1 interaction occurred with a low affinity compared with that measured for IL-8, the physiologic CXCR1 ligand. In all of its activities, p17 mimicked IL-8, the natural high-affinity ligand of CXCR1. Recent studies have highlighted the role of IL-8 and CXCR1 in HIV-1 replication and AIDS pathogenesis. Our findings herein call for an exploration of the therapeutic potential of blocking the p17/IL-8/CXCR1 axis in HIV-1 infection.

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.

An official ATS workshop report: Emerging issues and current controversies in HIV-associated pulmonary diseases

Pulmonary diseases are major causes of morbidity and death in persons with HIV infection. Millions of people with HIV/AIDS throughout the world are at risk of opportunistic pneumonias such as tuberculosis, bacterial pneumonia, and Pneumocystis pneumonia. However, the availability of combination antiretroviral therapy has turned HIV into a chronic disease, and noninfectious lung diseases such as lung cancer, chronic obstructive pulmonary disease, and pulmonary arterial hypertension are also emerging as important causes of illness. Despite the importance of these diseases and the rapidly evolving understanding of their pathogenesis and epidemiology, few avenues exist for the discussion and dissemination of new clinical and basic insights. In May of 2008, the American Thoracic Society sponsored a 1-day workshop, "Emerging Issues and Current Controversies in HIV-Associated Pulmonary Diseases," which brought together basic and clinical researchers in HIV-associated pulmonary disease. A review of the literature was performed by workshop participants, and the workshop included 18 presentations on diverse topics summarized in this article.

Liver transplantation in HCV/HIV positive patients

Since the introduction of highly active antiretroviral therapy (HAART) in 1996 for human immunodeficiency virus (HIV)-infected patients, the incidence of liver diseases secondary to co-infection with hepatitis C has increased. Although data on the outcome of liver transplantation in HIV-infected recipients is limited, the overall results to date seem to be comparable to that in non-HIV-infected recipients. Liver transplant centers are now accepting HIV-infected individuals as organ recipients. Post-transplantation HIV replication is controlled by HAART. Hepatitis C re-infection of the liver graft, however, remains an important problem because cirrhotic changes of the liver graft may be more rapid in HIV-infected recipients. Interactions between the HAART components and immunosuppressive drugs influence drug metabolism and therefore meticulous monitoring of drug blood level concentrations is required. The risk of opportunistic infection in HIV-positive transplant patients seems to be similar to that in HIV-negative transplant recipients.

Differing spectrum of HIV-associated ophthalmic disease among patients starting antiretroviral therapy in India and South Africa

Differences in the prevalence and spectrum of HIV-associated ophthalmic disease in Africa and Asia are not well documented. We studied two comparable cohorts of patients initiating antiretroviral therapy in Mumbai, India, and Cape Town, South Africa. The prevalence of HIV-associated ophthalmic disease was higher in the Indian population (17.5%) than in the South African population (12.1%). This was largely because of vitreo-retinal opportunistic infections (11.4%vs. 2.6%, respectively), notably cytomegalovirus retinitis. This difference persisted after adjusting for confounding factors (adjusted odds ratio = 11.32, 95% confidence interval: 2.67–48.13), confirming a marked geographical difference in the prevalence of HIV-associated retinal disease.

HIV-induced immune activation: pathogenesis and clinical relevance - summary of a workshop organized by the German AIDS Society (DAIG e.v.) and the ICH Hamburg, Hamburg, Germany, November 22, 2008

This manuscript is communicated by the German AIDS Society (DAIG) http://www.daignet.de. It summarizes a series of presentations and discussions during a workshop on immune activation due to HIV infection. The workshop was held on November 22^nd 2008 in Hamburg, Germany. It was organized by the ICH Hamburg under the auspices of the German AIDS Society (DAIG e.V.).

Fetal death as a result of placental immune reconstitution inflammatory syndrome

A 26-year-old woman was HIV-1 diagnosed at 11 weeks of pregnancy (CD4 = 7/mm(3), HIV-1 RNA = 108,000 copies/mL) with immunity against toxoplasmosis (Toxoplasma IgG = 1800 UI/mL). A fetal death was diagnosed 7 weeks after starting HAART (CD4 = 185/mm(3), HIV-1 RNA = 391 copies/mL) with a positive Toxoplasma PCR on fetal tissues and amniotic fluid. The absence of severe toxoplasmic foetopathy, the very exaggerated and atypical placental inflammation and the immune restoration context led to the diagnosis of placental IRIS associated with Toxoplasma gondii reactivation. This outcome remains undescribed and could represent an issue in resource-limited settings where HIV-pregnant patients are often severely immunodeficient and infected with opportunistic pathogens.

Pulmonary complications of immune reconstitution inflammatory syndromes in HIV-infected patients

Immune reconstitution inflammatory syndrome (IRIS) describes a paradoxical worsening of clinical status related to recovery of the immune system, as can occur after the initiation of highly active antiretroviral therapy (HAART) in HIV-infected patients. Most commonly, IRIS results from opportunistic infections that can unmask or develop paradoxical worsening following HAART. Cancers, autoimmune conditions and sarcoidosis have also been associated with IRIS. Pulmonary complications may be frequently encountered. This article reviews the types and clinical presentation of IRIS, with a focus on the pulmonary manifestations. Management and outcome of IRIS are considered.

Immune reconstitution syndrome and the thyroid

Reconstitution Graves' disease occurs in three settings. First, bone marrow transplantation from a donor with Graves' disease may cause this disease to appear in the recipient, as a result of adoptive immunity, although disordered immunoregulation secondary to graft-versus-host disease may also play a role. Second, alemtuzumab treatment for multiple sclerosis leads to the development of Graves' disease in up to a third of patients during the phase of naive T-cell expansion, which follows therapeutic lymphocyte depletion. Other reconstitution autoimmune phenomena, including immune thrombocytopaenic purpura, are also recognised after alemtuzumab administration. Finally, reconstitution Graves' disease may occur during a similar phase of CD4(+) T-cell expansion, which follows highly active antiretroviral therapy for human immunodeficiency virus infection. Again, this complication is part of a broader spectrum of immunoregulatory disturbances, which can arise after immune reconstitution. The mechanisms responsible for reconstitution Graves' disease are at present unclear, but may include a relative bias towards a Th2-mediated immune response and reduced competition for autoreactive lymphocytes to expand during the time when recovery from lymphopenia commences.

A brief review of potential mechanisms of immune reconstitution inflammatory syndrome in HIV following antiretroviral therapy

A subset of HIV-infected individuals who receive antiretroviral therapy (ART) develop a paradoxical pathological response that significantly increases morbidity and sometimes mortality. Following the induction of highly active ART, a rapid decline in the viral load results within weeks and coincides with a steep rise in the CD4(+) T-cell counts and immune hyperactivation. Although no mechanistic pathway has been elucidated for the development of immune reconstitution inflammatory syndrome (IRIS), it is thought that change in the nature of the immune response is a predominant factor in the development of reconstitution disease. In this article, we review the current state of knowledge in this field and provide a model for the development of IRIS.

[Human immunodeficiency virus and AIDS-associated immune reconstitution syndrome. State of the art]

Since the arrival of highly active antiretroviral therapy (HAART), immune reconstitution syndrome (IRS) has become an increasingly more frequent complication in patients with human immunodeficiency virus (HIV) infection. This article presents a review of the available evidence on this subject, indexed in MEDLINE-PUBMED, BVS-BIREME, and BioMed Central. The review covers the definition, epidemiology, classification, and diagnostic criteria related to IRS. In addition, the clinical particularities of the most frequent etiologies are described, and a proposal for a therapeutic approach is formulated. The prognosis and future implications of this syndrome in the epidemiology of some infectious illnesses in the HIV-positive population are included. Several unresolved aspects are mentioned, such as those related to the pathophysiology of the condition, use of biomarkers for the diagnosis, and the need for evidence-based therapeutic algorithms to enable standardization of treatment for these patients.

Graves' disease during immune reconstitution in HIV-infected patients treated with HAART

Autoimmune phenomena after immune recovery due to HAART are not frequently described. Recently we found 3 patients with Graves' disease after starting HAART, outnumbering the expected incidence; 13 patients have been reported in the literature up to the present time.A probable relation between immune restoration and development of Graves' disease might be suspected.

Human papillomavirus in the era of highly active antiretroviral therapy for human immunodeficiency virus: an immune reconstitution-associated disease?

Human immunodeficiency virus (HIV)-related cutaneous and anogenital disease in the highly active antiretroviral therapy (HAART) era presents challenging problems for dermatologists. Immune reconstitution-associated diseases (IRADs) are common and important consequences of HAART. Dermatologists should be aware of the cutaneous manifestations of IRAD. The prevalence of clinical human papillomavirus (HPV)-related disease is increased in HIV and does not appear to be diminished by HAART. Many patients on HAART are dogged by persistent cutaneous warts. Anogenital precancer is also common in HIV and may be burgeoning with HAART. Clinicians should be aware of the increased risk of cervical, penile and vulval/vaginal cancers in treated and untreated patients with HIV. The increase in HPV infection in HIV-infected individuals may be, at least partly, due to increased exposure to diverse HPV types, particularly high-risk types that might be able to persist for longer in anogenital regions. Alternatively, persistent/emergent HPV disease in HIV infection might represent persistent or modulated immunodysregulation after HAART and be viewed as a form of IRAD. The immunopathogenesis of HPV IRAD is fascinating and possibly determined by host genotype.

Bullous skin eruption in an HIV patient during antiretroviral drugs therapy

Dermo-epidermal blistering is an uncommon presentation of adverse drug reactions. Several drugs are associated to such eruptions, but review of current knowledge does not list antiretroviral drugs. A 37-year-old Caucasian HIV-positive woman presented with a 6-week history of diffuse annular blistering affecting the trunk and limbs. Lesions appeared both on erythematous and normal-appearing skin. The patient was in treatment with antiretroviral (lamivudine + didanosine + nelfinavir) for 2 years. A history of previous adverse reactions to betalactams, nonsteroidal anti-inflammatory drugs, and a nevirapine-induced hepatitis was also referred. Histopathology showed a dermo-epidermal blister; direct immunofluorescence was positive for IgG, C3c at the basement membrane zone; enzyme-linked immunosorbent assay was positive for BP180 antigen. Oral prednisone 1 mg/kg daily for 20 days led to poor improvement. Discontinuation of the antiretrovirals was followed by a rapid healing. Blisters reappeared at first re-introduction essay 1 month later. Awareness of iatrogenic dermo-epidermal blistering is necessary to suspect the diagnosis and avoid long-term immunosuppressant treatment. Complete spontaneous recovery after withdrawal of the responsible drug and relapse at rechallenge are the main criteria for the diagnosis. Factors related to the state of the HIV infection, and/or immunodeficiency may have contributed in precipitating the reaction in the present authors' case.

Immunological profiles of immune restoration disease presenting as mycobacterial lymphadenitis and cryptococcal meningitis

OBJECTIVES

A proportion of HIV patients beginning antiretroviral therapy (ART) develop immune restoration disease (IRD). Immunological characteristics of IRD were investigated in a cohort of HIV patients beginning therapy in Kuala Lumpur, Malaysia.

METHODS

Peripheral blood mononuclear cells were collected at weeks 0, 6, 12, 24 and 48 of ART from five patients experiencing IRD [two with cryptococcal and three with Mycobacterium tuberculosis (Mtb) disease], eight non-IRD controls who had begun ART with CD4 T-cell counts of <100 cells/microL and 17 healthy controls. Leukocytes producing interferon-gamma (IFNgamma) were quantified by enzyme-linked immunospot assay after stimulation with purified protein derivative (PPD), early secretory antigenic target-6 (ESAT-6), Cryptococcus neoformans or Cytomegalovirus antigens. Plasma immunoglobulin (IgG) antibodies reactive with these antigens were assessed by enzyme-linked immunosorbent assay. Proportions of activated (HLA-DR(hi)) and regulatory (CD25 CD127(lo) and CTLA-4(+)) CD4 T-cells were quantified by flow cytometry.

RESULTS

Plasma HIV RNA declined and CD4 T-cell counts rose within 8-27 weeks on ART. Mtb IRD patients displayed elevated IFNgamma responses and/or plasma IgG to PPD, but none responded to ESAT-6. Cryptococcal IRD occurred in patients with low baseline CD4 T-cell counts and involved clear IFNgamma and antibody responses to cryptococcal antigen. Proportions of activated and regulatory CD4 T-cells declined on ART, but remained higher in patients than in healthy controls. At the time of IRD, proportions of activated CD4 T-cells and regulatory CD4 T-cells were generally elevated relative to other patients.

CONCLUSIONS

Cryptococcal and Mtb IRD generally coincide with peaks in the proportion of activated T-cells, pathogen-specific IFNgamma responses and reactive plasma IgG. IRD does not reflect a paucity of regulatory CD4 T-cells.

Immune reconstitution inflammatory syndrome in HIV-infected patients receiving antiretroviral therapy : pathogenesis, clinical manifestations and management

The use of antiretroviral therapy (ART) to treat HIV infection, by restoring CD4+ cell count and immune function, is associated with significant reductions in morbidity and mortality. Soon after ART initiation, there is a rapid phase of restoration of pathogen-specific immunity. In certain patients, this results in inflammatory responses that may result in clinical deterioration known as 'the immune reconstitution inflammatory syndrome' (IRIS). IRIS may be targeted at viable infective antigens, dead or dying infective antigens, host antigens, tumour antigens and other antigens, giving rise to a heterogeneous range of clinical manifestations. The commonest forms of IRIS are associated with mycobacterial infections, fungi and herpes viruses. In most patients, ART should be continued and treatment for the associated condition optimized, and there is anecdotal evidence for the use of corticosteroids in patients who are severely affected. In this review, we discuss research relating to pathogenesis, the range of clinical manifestations, treatment options and prevention issues.