Immune reconstitution disorders in patients with HIV infection: from pathogenesis to prevention and treatment

HIV RNA/DNA Levels at Diagnosis Can Predict Immune Reconstitution: A Longitudinal Analysis

BACKGROUND

HIV DNA mirrors the number of infected cells and the size of the HIV viral reservoir. The aim of this study was to evaluate the effect of pre-cART HIV DNA levels as a predictive marker of immune reconstitution and on the post-cART CD4 counts trends.

METHODS

HIV DNA was isolated from PBMCs and quantified by real-time PCR. Immune reconstitution was assessed up to four years. Piecewise-linear mixed models were used to describe CD4 count changes.

RESULTS

148 people living with HIV (PLWH) were included. The highest rate of immune reconstitution was observed during the first trimester. There was a trend showing that high HIV RNA level resulted in greater increase in CD4 count, especially during the first trimester of cART (difference above vs. below median 15.1 cells/μL/month; 95% CI -1.4-31.5; p = 0.073). Likewise, higher HIV DNA level would predict greater CD4 increases, especially after the first trimester (difference above vs. below median 1.2 cells/μL/month; 95% CI -0.1-2.6; p = 0.071). Higher DNA and RNA levels combined were significantly associated with greater CD4 increase past the first trimester (difference high/high vs. low/low 2.1 cells/μL/month; 95% CI 0.3-4.0; p = 0.024). In multivariable analysis, lower baseline CD4 counts predicted a greater CD4 rise.

CONCLUSIONS

In successfully treated PLWH, pre-cART HIV DNA and HIV RNA levels are predictors of immune reconstitution.

Changes in the balance of Th17/Treg cells and oxidative stress markers in patients with HIV‑associated pulmonary tuberculosis who develop IRIS

Tuberculosis (TB) is the most common opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) infection and is one of the primary causes of death from AIDS. The increased accessibility to highly active antiretroviral therapy (HAART) has significantly improved the clinical outcome of patients with HIV infection. However, following ART, rapid restoration of the immune system leads to immune reconstitution inflammatory syndrome (IRIS). Oxidative stress and innate immunity play a role in TB-associated IRIS (TB-IRIS). The present study investigated the changes that occur in oxidative stress markers and T helper (Th)17/regulatory T (Treg) cell balance and their significance in IRIS patients with HIV-associated pulmonary TB. A total of 316 patients with HIV-associated pulmonary TB were treated with HAART and followed up regularly for 12 weeks. Those who developed IRIS were included in the IRIS group (n=60), while the remaining patients were included in the non-IRIS group (n=256). The changes in plasma oxidative stress markers superoxide dismutase (SOD) and malondialdehyde (MDA) were detected with the ELISA, and the ratio of Th17 to Treg cells in whole blood were analyzed before and after treatment through the flow cytometric assay. Following treatment, MDA and Th17 cells levels were significantly increased while SOD and Treg cells levels were decreased in the IRIS group (P<0.05) compared with before treatment. In the non-IRIS group, a non-significant decrease was observed in SOD levels (P>0.05), while the MDA levels significantly decreased compared with before treatment (P<0.05) and the Th17 and Treg cells levels were both significantly increased (P<0.05). After treatment, compared with the non-IRIS group, the IRIS group showed a significant increase in MDA and Th17 cells and decrease in SOD and Treg cells levels (P<0.05). In addition, Th17 cells levels were positively correlated with MDA but negatively correlated with SOD levels. Treg levels were negatively correlated with MDA and positively correlated with SOD levels (P<0.05). The area under the curve values of serum MDA and SOD, Th17 and Treg levels predicting the occurrence of IRIS were 0.738, 0.883, 0.722 and 0.719, respectively (P<0.05). These results indicated that the above parameters have certain diagnostic value for the occurrence of IRIS. The occurrence of IRIS in patients with HIV-associated pulmonary TB may be associated with oxidative stress and Th17/Treg cell imbalance.

Microbiological Investigations of Fine Needle Aspirates from Newly Suspected and Previously Treated Tubercular Lymphadenitis Patients

Background

Extrapulmonary tuberculosis (EPTB), particularly tubercular lymphadenitis (TBLN), remains to pose a huge public health problem in Ethiopia. A significant number of TBLN patients who completed a full course anti-TB treatment regimen were reported to have enlarged lymph nodes and other TB-like clinical presentations. This could either be from a paradoxical reaction or microbiological relapse, possibly due to mono/multi-drug resistance.

Objective

To investigate the rate of mono and multidrug resistance patterns of Mycobacterium tuberculosis as a cause of the observed treatment failures in clinically diagnosed and anti-TB treatment (newly or previously)-initiated LN patients.

Methods

A cross-sectional study was conducted on 126 TBLN-suspected and previously treated patients between March and September 2022. Data were analyzed using SPSS (Version 26.0). Descriptive statistics were used to determine the frequency, percentage, sensitivity, specificity, and positive and negative predictive values. The level of agreement was determined using Cohen's kappa and a Chi-square test was used to measure the association between risk factors and laboratory test outcomes. A P-value <0.05 was considered statistically significant.

Results

Mycobacterium tuberculosis was confirmed in 28.6% (N=36) of the 126 cases using BACTEC MGIT 960 culture detection method. Approximately, 13% (N=16) of the samples were collected from previously treated TBLN patients, of which 5/16 (31.3%) were multi-drug resistant, 7/16 were drug-sensitive and 4/16 were culture negative. To rule out other non-tuberculous agents, all samples were grown on blood and Mycosel agar plates, and no growth was detected.

Conclusion

The emergence of drug resistant (DR) TB seems to not just be limited to pulmonary form but also to TBLN. In this study we observed a considerable number of microbiologically confirmed relapses among previously treated cases, possibly indicating the need for confirmation of drug resistance using rapid molecular methods or phenotypical methods during treatment follow up.

Correlation Between CD4 Cell Count, HIV Viral Load, and Chest CT Findings of AIDS-associated Pulmonary Cryptococcosis

Background: The computed tomography (CT) features of acquired immune deficiency syndrome (AIDS)-associated pulmonary cryptococcosis (PC) are correlated with the viral load of human immunodeficiency virus (HIV). An increase in CD4-positive T lymphocyte (CD4) cell count in peripheral blood after a highly active antiretroviral therapy (HAART) can reflect the morphological changes of lung lesions. Objectives: This study aimed to evaluate the correlation between CT features and HIV viral load and to determine a cut-off value for CD4 cell count increment to investigate the prognosis of PC. It also aimed to examine the morphology of PC lesions and their prognosis following HAART. Methods: Sixty-two patients with AIDS-associated PC, confirmed by pathology or follow-up, were enrolled in this study. The CT findings were recorded and classified as nodular, cavitary, and consolidation groups and their subtypes. Forty HIV patients who had undergone HAART were screened in this study, and the outcomes of lung lesions were recorded in a follow-up of 3 - 6 months. The participants were divided into improvement and progression groups. The correlation analysis and the receiver operator characteristic (ROC) curve analysis were used to examine the correlation between CT morphology and HIV viral load and to determine the cut-off value for CD4 cell count increment. The intraclass correlation coefficient (ICC) for inter-observer agreement was also calculated. Results: In the nodular group, patients with miliary nodules had the highest HIV viral load in peripheral blood (miliary nodules vs. solitary nodules, P = 0.009; miliary nodules vs. multiple nodules; P = 0.024). In the cavitary group, thick-walled cavity lesions had a higher HIV viral load than thin-walled cavity lesions (thin-walled vs. thick-walled cavity lesions, P = 0.036). Changes in the morphology of lesions, indicating the progression or improvement of PC, had a positive correlation with the CD4 cell count increment (F = 4.260, P = 0.045). The cut-off value for CD4 cell count increment to differentiate the two outcomes (progression and improvement) was 44/µL. The area under the curve (AUC) was 0.851, and sensitivity, specificity, and accuracy were estimated at 0.815, 0.714, and 0.764, respectively. Conclusion: In AIDS-associated PC, different types of lesions were related to the HIV viral load, and CD4 cell count increment following HAART was associated with the morphological changes of lesions. This finding can be helpful for clinicians and radiologists to make an accurate diagnosis and evaluate the treatment outcomes, as well as disease progression.

Association between severe anaemia and inflammation, risk of IRIS and death in persons with HIV: A multinational cohort study

BACKGROUND

After initiating antiretroviral therapy (ART), approximately 25% of people with HIV (PWH) may develop Immune Reconstitution Inflammatory Syndrome (IRIS), which is associated with increased morbidity and mortality. Several reports have demonstrated that low haemoglobin (Hb) levels are a risk factor for IRIS. To what extent the severity of anaemia contributes to the risk of IRIS and/or death is still insufficiently explored.

METHODS

We investigated both the presence and severity of anaemia in PWH in a multinational cohort of ART-naïve patients. A large panel of plasma biomarkers was measured pre-ART and patients were followed up for 6 months. IRIS or deaths during this period were considered as outcomes. We performed multidimensional analyses, logistic regression, and survival curves to delineate associations.

FINDINGS

Patients with severe anaemia (SA) presented a distinct systemic inflammatory profile, characterized by higher TNF, IL-6, and IL-27 levels. SA was independently associated with IRIS, with a higher risk of both early IRIS onset and death. Among IRIS patients, those with SA had a higher risk of mycobacterial IRIS.

INTERPRETATION

PWH with SA display a more pronounced inflammatory profile, with an elevated risk of developing IRIS earlier and a statistically significant higher risk of death.

FUNDING

Intramural Research Program of National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH). Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Finance code: 001) and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil.

Inflammasome genetic variants are associated with tuberculosis, HIV-1 infection, and TB/HIV-immune reconstitution inflammatory syndrome outcomes

Background

Tuberculosis (TB) and AIDS are the leading causes of infectious diseases death worldwide. Here, we investigated the relationship between from single nucleotide polymorphisms (SNPs) of the NLRP3, CARD8, AIM2, CASP-1, IFI16, and IL-1β inflammasome genes, as well as the profiles of secreted proinflammatory cytokines (e.g., IL-1β, IL-18, IL-33, and IL-6) with the TB clinical profiles, TB-HIV coinfection, and IRIS onset.

Methods

The individuals were divided into four groups: TB-HIV group (n=88; 11 of them with IRIS), HIV-1 group (n=20), TB group (n=24) and healthy volunteers (HC) group (n=10), and were followed up at INI/FIOCRUZ and HGNI (Rio de Janeiro/Brazil) from 2006 to 2016. Real-time PCR was used to determine the genotypes of the Single Nucleotide Polymorphism (SNPs), and ELISA was used to measure the plasma cytokine levels. Unconditional logistic regression models were used to perform risk estimations.

Results

A higher risk for extrapulmonary TB was associated with the TT genotype (aOR=6.76; P=0.026) in the NLRP3 rs4612666 Single Nucleotide Polymorphism (SNP) and the C-C-T-G-C haplotype (aOR=4.99; P= 0.017) in the NLRP3 variants. This same Single Nucleotide Polymorphism (SNP) was associated with lower risk against extrapulmonary TB when the carrier allele C (aOR=0.15; P=0.021) was present. Among those with HIV-1 infections, a higher risk for TB onset was associated with the GA genotype (aOR=5.5; P=0.044) in the IL1-β rs1143634 Single Nucleotide Polymorphism (SNP). In contrast, lower risk against TB onset was associated with the A-G haplotype (aOR=0.17; P= 0.026) in the CARD8 variants. Higher IL-6 and IL-33 levels were observed in individuals with TB. A higher risk for IRIS onset was associated with CD8 counts ≤ 500 cells/mm3 (aOR=12.32; P=0.010), the presence of extrapulmonary TB (aOR=6.6; P=0.038), and the CT genotype (aOR=61.06; P=0.026) or carrier allele T (aOR=61.06; P=0.026) in the AIM2 rs2276405 Single Nucleotide Polymorphism (SNP), whereas lower risk against IRIS onset was associated with the AT genotype (aOR=0.02; P=0.033) or carrier allele T (aOR=0.02; P=0.029) in the CARD8 rs2043211 Single Nucleotide Polymorphism (SNP) and the T-G haplotype (aOR=0.07; P= 0.033) in the CARD8 variants. No other significant associations were observed.

Conclusions

Our results depict the involvement of genetic polymorphisms of crucial innate immunity genes and proinflammatory cytokines in the clinical outcomes related to TB-HIV coinfection.

Biotypes of HIV-associated neurocognitive disorders based on viral and immune pathogenesis

PURPOSE OF REVIEW

HIV-associated neurocognitive disorders (HAND) continues to be prevalent in people living with HIV despite antiretroviral therapy. However, understanding disease mechanisms and identifying therapeutic avenues has been challenging. One of the challenges is that HAND is a heterogeneous disease and that patients identified with similar impairments phenotypically may have very different underlying disease processes. As the NeuroAIDS field is re-evaluating the approaches used to identify patients with HIV-associated neurological impairments, we propose the subtyping of patients into biotypes based on viral and immune pathogenesis.

RECENT FINDINGS

Here we review the evidence supporting subtyping patients with HIV-associated neurological complications into four biotypes: macrophage-mediated HIV encephalitis, CNS viral escape, T-cell-mediated HIV encephalitis, and HIV protein-associated encephalopathy.

SUMMARY

Subtyping patients into subgroups based on biotypes has emerged as a useful approach for studying heterogeneous diseases. Understanding biotypes of HIV-associated neurocognitive impairments may therefore enable better understanding of disease mechanisms, allow for the development of prognostic and diagnostic markers, and could ultimately guide therapeutic decisions.

Active Pharmacovigilance Project on the safety profile of Dolutegravir in Brazil

A quantitative descriptive study based on Brazilian Active Pharmacovigilance of Dolutegravir (DTG) Project was performed to describe the adverse drug reactions (ADRs) to DTG reported and to evaluate the noncompleteness of data from DTG active pharmacovigilance in Brazil. ADRs and clinical and individual data were obtained from information from the Pharmacovigilance Questionnaire from April 2017 to August 2019. The reported ADRs were classified using the Medical Dictionary for Regulatory Activities (MedDRA). In the evaluated period, 249,066 individuals using DTG participated in the active pharmacovigilance of DTG, with 3472 (1.39%) reporting ADRs at least once. A total of 6312 ADRs were reported, of which 57.56% were persistent and 81.46% were not serious according to the individuals' reports. Most of the reported ADRs were gastrointestinal, neurological and psychiatric. ADRs related to neural tube defects and serious neuropsychiatric ADRs have been reported. Completion of more than half of the fields in the Pharmacovigilance Questionnaire was excellent. The frequency of ADR was low in relation to the number of people living with HIV (PLHIV) using DTG in Brazil, which suggests good tolerability and safety of DTG. The DTG active pharmacovigilance database in Brazil showed good data completeness.

Rapid Emergence of T Follicular Helper and Germinal Center B Cells Following Antiretroviral Therapy in Advanced HIV Disease

Low nadir CD4 T-cell counts in HIV+ patients are associated with high morbidity and mortality and lasting immune dysfunction, even after antiretroviral therapy (ART). The early events of immune recovery of T cells and B cells in severely lymphopenic HIV+ patients have not been fully characterized. In a cohort of lymphopenic (CD4 T-cell count < 100/µL) HIV+ patients, we studied mononuclear cells isolated from peripheral blood (PB) and lymph nodes (LN) pre-ART (n = 40) and 6-8 weeks post-ART (n = 30) with evaluation of cellular immunophenotypes; histology on LN sections; functionality of circulating T follicular helper (cTfh) cells; transcriptional and B-cell receptor profile on unfractionated LN and PB samples; and plasma biomarker measurements. A group of 19 healthy controls (HC, n = 19) was used as a comparator. T-cell and B-cell lymphopenia was present in PB pre-ART in HIV+ patients. CD4:CD8 and CD4 T- and B-cell PB subsets partly normalized compared to HC post-ART as viral load decreased. Strikingly in LN, ART led to a rapid decrease in interferon signaling pathways and an increase in Tfh, germinal center and IgD-CD27- B cells, consistent with histological findings of post-ART follicular hyperplasia. However, there was evidence of cTfh cells with decreased helper capacity and of limited B-cell receptor diversification post-ART. In conclusion, we found early signs of immune reconstitution, evidenced by a surge in LN germinal center cells, albeit limited in functionality, in HIV+ patients who initiate ART late in disease.

A clinical rule for the prediction of meningitis in HIV patients in the era of combination antiretroviral therapy

BACKGROUND

The diagnosis of meningitis in HIV patients is challenging due to altered immune responses. Diagnostic scoring systems were recently proposed for use in research settings to help prompt and easy differential diagnosis. The objective of this study was to create a clinical prediction rule (CPR) for meningitis in HIV-infected patients and to address the enigma of differentiating bacterial (BM), TB (TBM) and cryptococcal (CCM) meningitis based on clinical features alone, which may be enhanced by easy-to-obtain laboratory testing.

METHODS

We retrospectively enrolled 352 HIV patients presenting with neurological manifestations suggesting meningitis over the last 18 y (2000-2018). Relevant clinical and laboratory information were retrieved from inpatient records. The features independently predicting meningitis or its different types in microbiologically proven meningitis cases were modelled by multivariate logistic regression to create a CPR in an exploratory data set. The performance of the meningitis diagnostic score was assessed and validated in a subset of retrospective data.

RESULTS

AIDS clinical stage, injecting drug use, jaundice and cryptococcal antigen seropositivity were equally important as classic meningitic symptoms in predicting meningitis. Arthralgia and elevated cerebrospinal fluid Lactate dehydrogenase (LDH) were strong predictors of BM. Patients with cryptococcal antigenemia had 25 times the probability of having CCM, whereas neurological deficits were highly suggestive of TBM.

CONCLUSION

The proposed CPRs have good diagnostic potential and would support decision-making in resource-poor settings.

Classical complement and inflammasome activation converge in CD14highCD16- monocytes in HIV associated TB-immune reconstitution inflammatory syndrome

Inflammasome-derived cytokines, IL-1β and IL-18, and complement cascade have been independently implicated in the pathogenesis of tuberculosis (TB)-immune reconstitution inflammatory syndrome (TB-IRIS), a complication affecting HIV⁺ individuals starting antiretroviral therapy (ART). Although sublytic deposition of the membrane attack complex (MAC) has been shown to promote NLRP3 inflammasome activation, it is unknown whether these pathways may cooperatively contribute to TB-IRIS. To evaluate the activation of inflammasome, peripheral blood mononuclear cells (PBMCs) from HIV-TB co-infected patients prior to ART and at the IRIS or equivalent timepoint were incubated with a probe used to assess active caspase-1/4/5 followed by screening of ASC (apoptosis-associated speck-like protein containing a CARD domain) specks as a readout of inflammasome activation by imaging flow cytometry. We found higher numbers of monocytes showing spontaneous caspase-1/4/5⁺ASC-speck formation in TB-IRIS compared to TB non-IRIS patients. Moreover, numbers of caspase-1/4/5⁺ASC-speck⁺ monocytes positively correlated with IL-1β/IL-18 plasma levels. Besides increased systemic levels of C1q and C5a, TB-IRIS patients also showed elevated C1q and C3 deposition on monocyte cell surface, suggesting aberrant classical complement activation. A clustering tSNE analysis revealed TB-IRIS patients are enriched in a CD14^highCD16^- monocyte population that undergoes MAC deposition and caspase-1/4/5 activation compared to TB non-IRIS patients, suggesting complement-associated inflammasome activation during IRIS events. Accordingly, PBMCs from patients were more sensitive to ex-vivo complement-mediated IL-1β secretion than healthy control cells in a NLRP3-dependent manner. Therefore, our data suggest complement-associated inflammasome activation may fuel the dysregulated TB-IRIS systemic inflammatory cascade and targeting this pathway may represent a novel therapeutic approach for IRIS or related inflammatory syndromes.

Tuberculosis (TB) associated-immune reconstitution inflammatory syndrome (TB-IRIS) is a clinical complication affecting HIV⁺ individuals previously co-infected with Mycobacterium tuberculosis (Mtb), upon antiretroviral therapy (ART) initiation. TB-IRIS is characterized by an exacerbated inflammatory response and can be associated with high morbidity and mortality rates in resource-limited countries with high TB prevalence. So far, there is no targeted TB-IRIS therapy, and corticosteroids are frequently used to prevent or alleviate IRIS related-symptoms. Here we found inflammasome activation (i.e. caspase1/4/5⁺ASC speck complex formation) on circulating classical CD14^highCD16^- monocytes may contribute to TB-IRIS immunopathology, since it correlates with pro-inflammatory cytokine plasma levels and its decay is associated with dampening in IRIS-related symptoms promoted by anti-inflammatory therapy. We also found TB-IRIS monocytes display higher surface complement deposition, being more sensitive to external complement-mediated NLRP3 inflammasome activation than healthy control cells. In fact, complement MAC molecule C9 and caspase-1/4/5 activation were associated on classical monocytes in TB-IRIS patients, suggesting complement-mediated inflammasome activation may lead to a positive feedback loop in the inflammatory responses observed in TB-IRIS. Therefore, our findings support that complement-NLRP3/ASC/caspase1/4/5 axis may be considered as a potential target for host-directed therapy of TB-IRIS.

State of the art of 18F-FDG PET/CT application in inflammation and infection: a guide for image acquisition and interpretation

AIM

The diagnosis, severity and extent of a sterile inflammation or a septic infection could be challenging since there is not one single test able to achieve an accurate diagnosis. The clinical use of 18F-fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) imaging in the assessment of inflammation and infection is increasing worldwide. The purpose of this paper is to achieve an Italian consensus document on [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases, such as osteomyelitis (OM), prosthetic joint infections (PJI), infective endocarditis (IE), prosthetic valve endocarditis (PVE), cardiac implantable electronic device infections (CIEDI), systemic and cardiac sarcoidosis (SS/CS), diabetic foot (DF), fungal infections (FI), tuberculosis (TBC), fever and inflammation of unknown origin (FUO/IUO), pediatric infections (PI), inflammatory bowel diseases (IBD), spine infections (SI), vascular graft infections (VGI), large vessel vasculitis (LVV), retroperitoneal fibrosis (RF) and COVID-19 infections.

METHODS

In September 2020, the inflammatory and infectious diseases focus group (IIFG) of the Italian Association of Nuclear Medicine (AIMN) proposed to realize a procedural paper about the clinical applications of [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases. The project was carried out thanks to the collaboration of 13 Italian nuclear medicine centers, with a consolidate experience in this field. With the endorsement of AIMN, IIFG contacted each center, and the pediatric diseases focus group (PDFC). IIFG provided for each team involved, a draft with essential information regarding the execution of [¹⁸F]FDG PET/CT or PET/MRI scan (i.e., indications, patient preparation, standard or specific acquisition modalities, interpretation criteria, reporting methods, pitfalls and artifacts), by limiting the literature research to the last 20 years. Moreover, some clinical cases were required from each center, to underline the teaching points. Time for the collection of each report was from October to December 2020.

RESULTS

Overall, we summarized 291 scientific papers and guidelines published between 1998 and 2021. Papers were divided in several sub-topics and summarized in the following paragraphs: clinical indications, image interpretation criteria, future perspectivess and new trends (for each single disease), while patient preparation, image acquisition, possible pitfalls and reporting modalities were described afterwards. Moreover, a specific section was dedicated to pediatric and PET/MRI indications. A collection of images was described for each indication.

CONCLUSIONS

Currently, [¹⁸F]FDG PET/CT in oncology is globally accepted and standardized in main diagnostic algorithms for neoplasms. In recent years, the ever-closer collaboration among different European associations has tried to overcome the absence of a standardization also in the field of inflammation and infections. The collaboration of several nuclear medicine centers with a long experience in this field, as well as among different AIMN focus groups represents a further attempt in this direction. We hope that this document will be the basis for a "common nuclear physicians' language" throughout all the country.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40336-021-00445-w.

Prospective International Study of Incidence and Predictors of Immune Reconstitution Inflammatory Syndrome and Death in People Living With Human Immunodeficiency Virus and Severe Lymphopenia

BACKGROUND

Patients living with human immunodeficiency virus (PLWH) with low CD4 counts are at high risk for immune reconstitution inflammatory syndrome (IRIS) and death at antiretroviral therapy (ART) initiation.

METHODS

We investigated the clinical impact of IRIS in PLWH and CD4 counts <100 cells/μL starting ART in an international, prospective study in the United States, Thailand, and Kenya. An independent review committee adjudicated IRIS events. We assessed associations between baseline biomarkers, IRIS, immune recovery at week 48, and death by week 48 with Cox models.

RESULTS

We enrolled 506 participants (39.3% were women). Median age was 37 years, and CD4 count was 29 cells/μL. Within 6 months of ART, 97 (19.2%) participants developed IRIS and 31 (6.5%) died. Participants with lower hemoglobin at baseline were at higher IRIS risk (hazard ratio [HR], 1.2; P = .004). IRIS was independently associated with increased risk of death after adjustment for known risk factors (HR, 3.2; P = .031). Being female (P = .004) and having a lower body mass index (BMI; P = .003), higher white blood cell count (P = .005), and higher D-dimer levels (P = .044) were also significantly associated with increased risk of death. Decision-tree analysis identified hemoglobin <8.5 g/dL as predictive of IRIS and C-reactive protein (CRP) >106 μg/mL and BMI <15.6 kg/m2 as predictive of death.

CONCLUSIONS

For PLWH with severe immunosuppression initiating ART, baseline low BMI and hemoglobin and high CRP and D-dimer levels may be clinically useful predictors of IRIS and death risk.

AIDS-associated Talaromyces marneffei central nervous system infection in patients of southwestern China

Background

The clinical and laboratory characteristics of AIDS-associated Talaromyces marneffei infection, a rare but a fatal mycosis disease of the central nervous system, remain unclear.

Case presentation

Herein, we conducted a retrospective study of ten AIDS patients with cerebrospinal fluid culture-confirmed central nervous system infection caused by Talaromyces marneffei. All 10 patients were promptly treated with antifungal treatment for a prolonged duration and early antiviral therapy (ART). Among them, seven patients were farmers. Nine patients were discharged after full recovery, while one patient died during hospitalization, resulting in a mortality rate of 10%. All patients initially presented symptoms and signs of an increase in intracranial pressure, mainly manifesting as headache, dizziness, vomiting, fever, decreased muscle strength, diplopia or even altered consciousness with seizures in severe patients. Nine patients (90%) showed lateral ventricle dilatation or intracranial infectious lesions on brain CT. Cerebrospinal fluid findings included elevated intracranial pressure, increased leukocyte count, low glucose, low chloride and high cerebrospinal fluid protein. The median CD4⁺ T count of patients was 104 cells/μL (IQR, 36–224 cells/μL) at the onset of the disease. The CD4⁺ T cell counts of three patients who eventually died were significantly lower (W = 6.00, p = 0.020) than those of the patients who survived.

Conclusions

The common clinical symptoms of T. marneffei central nervous system infection are associated with high intracranial pressure and intracranial infectious lesions. Earlier recognition and diagnosis and a prolonged course of amphotericin B treatment followed by itraconazole combined with early ART might reduce the mortality rate.

Pulmonary coinfection by Pneumocystis jirovecii and Cryptococcus species in a patient with undiagnosed advanced HIV

Pneumocystis jirovecii is a common cause of pneumonia in patients with advanced HIV. In a lot of cases, there is a concomitant pulmonary infection. Cryptococcosis presents as a common complication for people with advanced HIV. However, it usually presents as meningitis rather than pneumonia. We present a case of a patient with coinfection by P. jirovecii and Cryptococcus spp without neurological involvement and a single nodular pulmonary lesion.

Clinical and genetic markers associated with tuberculosis, HIV-1 infection, and TB/HIV-immune reconstitution inflammatory syndrome outcomes

BACKGROUND

Tuberculosis (TB) and AIDS are the leading causes of infectious disease death worldwide. In some TB-HIV co-infected individuals treated for both diseases simultaneously, a pathological inflammatory reaction termed immune reconstitution inflammatory syndrome (IRIS) may occur. The risk factors for IRIS are not fully defined. We investigated the association of HLA-B, HLA-C, and KIR genotypes with TB, HIV-1 infection, and IRIS onset.

METHODS

Patients were divided into four groups: Group 1- TB+/HIV+ (n = 88; 11 of them with IRIS), Group 2- HIV+ (n = 24), Group 3- TB+ (n = 24) and Group 4- healthy volunteers (n = 26). Patients were followed up at INI/FIOCRUZ and HGNI (Rio de Janeiro/Brazil) from 2006 to 2016. The HLA-B and HLA-C loci were typed using SBT, NGS, and KIR genes by PCR-SSP. Unconditional logistic regression models were performed for Protection/risk estimation.

RESULTS

Among the individuals with TB as the outcome, KIR2DS2 was associated with increased risk for TB onset (aOR = 2.39, P = 0.04), whereas HLA-B*08 and female gender were associated with protection against TB onset (aOR = 0.23, P = 0.03, and aOR = 0.33, P = 0.01, respectively). Not carrying KIR2DL3 (aOR = 0.18, P = 0.03) and carrying HLA-C*07 (aOR = 0.32, P = 0.04) were associated with protection against TB onset among HIV-infected patients. An increased risk for IRIS onset was associated with having a CD8 count ≤500 cells/mm3 (aOR = 18.23, P = 0.016); carrying the KIR2DS2 gene (aOR = 27.22, P = 0.032), the HLA-B*41 allele (aOR = 68.84, P = 0.033), the KIR2DS1 + HLA-C2 pair (aOR = 28.58, P = 0.024); and not carrying the KIR2DL3 + HLA-C1/C2 pair (aOR = 43.04, P = 0.034), and the KIR2DL1 + HLA-C1/C2 pair (aOR = 43.04, P = 0.034), CONCLUSIONS: These results suggest the participation of these genes in the immunopathogenic mechanisms related to the conditions studied. This is the first study demonstrating an association of HLA-B*41, KIR2DS2, and KIR + HLA-C pairs with IRIS onset among TB-HIV co-infected individuals.

Immune Reconstitution Disorders: Spotlight on Interferons

Three decades of research in hematopoietic stem cell transplantation and HIV/AIDS fields have shaped a picture of immune restoration disorders. This manuscript overviews the molecular biology of interferon networks, the molecular pathogenesis of immune reconstitution inflammatory syndrome, and post-hematopoietic stem cell transplantation immune restoration disorders (IRD). It also summarizes the effects of thymic involution on T cell diversity, and the results of the assessment of diagnostic biomarkers of IRD, and tested targeted immunomodulatory treatments.

Management of Advanced HIV Disease

Great progress has been made in caring for persons with human immunodeficiency virus. However, a significant proportion of individuals still present to care with advanced disease and a low CD4 count. Careful considerations for selection of antiretroviral therapy as well as close monitoring for opportunistic infections and immune reconstitution inflammatory syndrome are vitally important in providing care for such individuals.

Increased Metabolic Activity on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Human Immunodeficiency Virus-Associated Immune Reconstitution Inflammatory Syndrome

Background

Immune reconstitution inflammatory syndrome (IRIS) represents an unexpected inflammatory response shortly after initiation of antiretroviral therapy (ART) in some human immunodeficiency virus (HIV)-infected patients with underlying neoplasia or opportunistic infections, including tuberculosis. We hypothesized that IRIS is associated with increased glycolysis and that 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) could help identify high-risk subjects.

Methods

In this prospective cohort study, 30 HIV-infected patients (CD4+ count <100 cells/µL) underwent FDG-PET/CT scans at baseline and 4-8 weeks after ART initiation. Ten patients developed IRIS (6 mycobacterial).

Results

At baseline, total glycolytic activity, total lesion volume, and maximum standardized uptake values (SUVs) of pathologic FDG uptake (reflective of opportunistic disease burden) were significantly higher in IRIS vs non-IRIS (P = .010, .017, and .029, respectively) and significantly correlated with soluble inflammatory biomarkers (interferon-γ, myeloperoxidase, tumor necrosis factor, interleukin 6, soluble CD14). Baseline bone marrow (BM) and spleen FDG uptake was higher in mycobacterial IRIS specifically. After ART initiation, BM and spleen mean SUV decreased in non-IRIS (P = .004, .013) but not IRIS subjects. Our results were supported by significantly higher glucose transporter 1 (Glut-1) expression of CD4+ cells and monocytes after ART initiation in IRIS/mycobacterial IRIS compared with non-IRIS patients.

Conclusions

We conclude that increased pathologic metabolic activity on FDG-PET/CT prior to ART initiation is associated with IRIS development and correlates with inflammatory biomarkers. Abnormally elevated BM and spleen metabolism is associated with mycobacterial IRIS, HIV viremia, and Glut-1 expression on CD4+ cells and monocytes.

Clinical Trials Registration

NCT02147405.

Understanding mechanisms underlying the pathology of immune reconstitution inflammatory syndrome (IRIS) by using animal models

Purpose of Review

Despite the increasing number of clinical reports on immune reconstitution inflammatory syndrome (IRIS), mechanistic understanding of IRIS is still largely limited. The main focus of this review is to summarize animal studies, which were performed to better understand the cellular and molecular mechanisms underlying the pathology of IRIS.

Recent Findings

Three IRIS animal models have been reported. They are Mycobacterial IRIS (M-IRIS), cryptococcal IRIS (C-IRIS) and Pneumocystis-IRIS. M-IRIS animal model suggested that, rather than lymphopenia itself, the failure to clear the pathogen by T cells results in excessive priming of the innate immune system. If this happens before T cell reconstitution, hosts likely suffer IRIS upon T cell reconstitution. Interestingly, T cells specific to self-antigens, not only pathogen-specific, could drive IRIS as well.

Summary

The mechanism to develop IRIS is quite complicated, including multiple layers of host immune responses; the innate immune system that detects pathogens and prime host immunity, and the adaptive immune system that is reconstituted but hyper-activated particularly through CD4⁺ T cells. Animal models of IRIS, although there are still small numbers of studies available, have already provided significant insights on the mechanistic understanding of IRIS.

Assessing endocrine and immune parameters in human immunodeficiency virus-infected patients before and after the immune reconstitution inflammatory syndrome

Objective The present study compares immune and endocrine parameters between HIV-infected patients who underwent the Immune Reconstitution Inflammatory Syndrome (IRIS-P) during antiretroviral therapy (ART) and HIV-patients who did not undergo the syndrome (non-IRIS-P). Materials and methods Blood samples were obtained from 31 HIV-infected patients (15 IRIS-P and 16 non-IRIS-P) before ART (BT) and 48 ± 2 weeks after treatment initiation (AT). Plasma Interleukin-6 (IL-6) and Interleukin-18 (IL-18) were determined by ELISA. Cortisol, dehydroepiandrosterone sulfate (DHEA-S) and thyroxin concentrations were measured using chemiluminescence immune methods. Results Concentrations of IL-6 (7.9 ± 1.9 pg/mL) and IL-18 (951.5 ± 233.0 pg/mL) were significantly higher (p < 0.05) in IRIS-P than in non-IRIS-P (3.9 ± 1.0 pg/mL and 461.0 ± 84.4 pg/mL, respectively) BT. Mean T4 plasma level significantly decreased in both groups of patients after treatment (p < 0.05). In both groups cortisol levels were similar before and after ART (p > 0.05). Levels of DHEA-S in IRIS-P decreased AT (1080.5 ± 124.2 vs. 782.5 ± 123.8 ng/mL, p < 0.05) and they were significantly lower than in non-IRIS-P (782.5 ± 123.8 vs. 1203.7 ± 144.0 ng/mL, p < 0.05). IRIS-P showed higher values of IL-6 and IL-18 BT and lower levels of DHEA-S AT than in non-IRIS-P. Conclusion These parameters could contribute to differentiate IRIS-P from non-IRIS-P. The significant decrease in DHEA-S levels in IRIS-P after ART might suggest a different adrenal response in these patients, which may reflect the severity of the disease.

Epidemiology of autoimmune and inflammatory diseases in a French nationwide HIV cohort

BACKGROUND

HIV infection and inflammatory and autoimmune diseases (IADs) are both related to immune dysfunction. Epidemiological data on IAD in patients living with HIV (PLHIV) are scarce. The aim of this study was thus to estimate the prevalence of 26 IAD among PLHIV followed in a large French multicenter cohort in the combination antiretroviral therapy (cART) era (from January 2000 to July 2013), and to describe their occurrence according to cART onset, the immuno-virological status of patients and hepatitis C virus (HCV) and/or hepatitis B virus coinfection.

METHOD AND RESULTS

During the study period, 33 403 PLHIV were included in the Dat'AIDS cohort; 1381 patients with an IAD were identified. The most prevalent IADs were psoriasis, sarcoidosis, rheumatoid arthritis, ankylosing spondyloarthritis, Grave's disease, autoimmune hemolytic anemia, immune thrombocytopenia and chronic inflammatory bowel disease. In contrast, the prevalence of systemic lupus erythematosus and multiple sclerosis were low. Most patients (59%) developed IAD after HIV infection with a mean delay of 10.6 ± 6.4 years. Compared with the entire cohort, HCV coinfection was significantly more frequent in patients with psoriasis, Grave's disease and immune thrombocytopenia, and chronic hepatitis B in patients was more frequent in those with immune thrombocytopenia and autoimmune hemolytic anemia. Among patients developing IAD after the diagnosis of HIV infection, 572 (70%) were on antiretroviral therapy and 419 of them (73%) had undetectable HIV viral load.

CONCLUSION

Our study showed that some IAD are not rare among PLHIV and occur mostly in patients with immuno-virological control under cART. The higher frequency of HCV or hepatitis B virus coinfection for some IAD is also confirmed.

Toxoplasmosis-associated IRIS involving the CNS: a case report with longitudinal analysis of T cell subsets

Background

HIV-infected patients may present an unforeseen clinical worsening after initiating antiretroviral therapy known as immune reconstitution inflammatory syndrome (IRIS). This syndrome is characterized by a heightened inflammatory response toward infectious or non-infectious triggers, and it may affect different organs. Diagnosis of IRIS involving the central nervous system (CNS-IRIS) is challenging due to heterogeneous manifestations, absence of biomarkers to identify this condition, risk of long-term sequelae and high mortality. Hence, a deeper knowledge of CNS-IRIS pathogenesis is needed.

Case presentation

A 37-year-old man was diagnosed with AIDS and cerebral toxoplasmosis. Anti-toxoplasma treatment was initiated immediately, followed by active antiretroviral therapy (HAART) 1 month later. At 2 months of HAART, he presented with progressive hyposensitivity of the right lower limb associated with brain and dorsal spinal cord lesions, compatible with paradoxical toxoplasmosis-associated CNS-IRIS, a condition with very few reported cases. A stereotactic biopsy was planned but was postponed based on its inherent risks. Patient showed clinical improvement with no requirement of corticosteroid therapy. Routine laboratorial analysis was complemented with longitudinal evaluation of blood T cell subsets at 0, 1, 2, 3 and 6 months upon HAART initiation. A control group composed by 9 HIV-infected patients from the same hospital but with no IRIS was analysed for comparison. The CNS-IRIS patient showed lower percentage of memory CD4⁺ T cells and higher percentage of activated CD4⁺ T cells at HAART initiation. The percentage of memory CD4⁺ T cells drastically increased at 1 month after HAART initiation and became higher in comparison to the control group until clinical recovery onset; the percentage of memory CD8⁺ T cells was consistently lower throughout follow-up. Interestingly, the percentage of regulatory T cells (Treg) on the CNS-IRIS patient reached a minimum around 1 month before symptoms onset.

Conclusion

Although both stereotactic biopsies and steroid therapy might be of use in CNS-IRIS cases and should be considered for these patients, they might be unnecessary to achieve clinical improvement as shown in this case. Immunological characterization of more CNS-IRIS cases is essential to shed some light on the pathogenesis of this condition.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2159-x) contains supplementary material, which is available to authorized users.

Immune reconstitution inflammatory syndrome in HIV infection: taking the bad with the good

In this review, we will describe the immunopathogies of immune reconstitution inflammatory syndrome, IRIS. IRIS occurs in a small subset of HIV patient, initiating combination antiretroviral therapy (ART), where immune reconstitution becomes dysregulated, resulting in an overly robust antigen-specific inflammatory reaction. We will discuss IRIS in terms of the associated coinfections: mycobacteria, cryptococci, and viruses.

HIV infection and immune activation: the role of coinfections

PURPOSE OF REVIEW

This article explores new data from recent studies addressing the role of coinfections in immune activation in HIV-1-infected patients, with a focus on immune reconstitution inflammatory syndrome (IRIS), an aberrant inflammatory response occurring shortly after antiretroviral therapy (ART) initiation.

RECENT FINDINGS

Chronic HIV infection is associated with several coinfections that contribute to immune activation in various settings including early after ART initiation in the most noticeable form of IRIS and also in chronic-treated infection, with chronic viral infections like cytomegalovirus and hepatitis C or hepatitis B virus contributing to immune activation and also morbidity and mortality. Expanding on older studies, the role of T cells in IRIS has been further elucidated with evidence of more pronounced effector activity in patients with IRIS that may be leading to excessive tissue disorder. Newer studies are also continuing to shed light on the role of myeloid cells as well as the contribution of antigen load in IRIS. In addition, preliminary data are beginning to suggest a possible role of inflammasome formation in IRIS. In cryptococcal IRIS, the role of activated immune cells (T cell and myeloid) and biomarkers were evaluated in more detail at the site of infection (cerebrospinal fluid). Finally, important differences of patients developing IRIS versus those who die from tuberculosis despite ART initiation were reported, a distinction that may have important implications for participant selection in studies aiming to prevent IRIS with immunosuppressive agents.

SUMMARY

Better understanding of the role of opportunistic infections at ART initiation and IRIS pathogenesis will assist in improved strategies for prevention and treatment. The long-term consequences of IRIS remain unclear. Chronic viral coinfections with herpesviruses and hepatitis C virus are important factors in persistent immune activation in chronic-treated HIV.

Therapeutics targeting inflammation in the immune reconstitution inflammatory syndrome

Immune reconstitution inflammatory syndrome (IRIS) is characterized by improvement in a previously incompetent human immune system manifesting as worsening of clinical symptoms secondary to the ability of the immune system to now mount a vigorous inflammatory response. IRIS was first recognized in the setting of human immunodeficiency virus, and this clinical setting continues to be where it is most frequently encountered. Hallmarks of the pathogenesis of IRIS, independent of the clinical presentation and the underlying pathogen, include excessive activation of the immune system, with increased circulating effector memory T cells, and elevated levels of serum cytokines and inflammatory markers. Patients with undiagnosed opportunistic infections remain at risk for unmasking IRIS at the time of active antiretroviral therapy (ART) initiation. Systematic screening for opportunistic infections before starting ART is a key element to prevent this phenomenon. Appropriate management of IRIS requires prompt recognition of the syndrome and exclusion of alternative diagnoses, particularly underlying infections and drug resistance. Controlled studies supporting the use of pharmacologic interventions in IRIS are scare, and recommendations are based on case series and expert opinions. The only controlled trial published to date, showed reduction in morbidity in patients with paradoxical tuberculosis-related IRIS with the use of oral corticosteroids. There are currently limited data to recommend other anti-inflammatory or immunomodulatory therapies that are discussed in this review, and further research is needed. Ongoing research regarding the immune pathogenesis of IRIS will likely direct future rational therapeutic approaches and clinical trials.

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.

Plasma interleukin-18 levels are a biomarker of innate immune responses that predict and characterize tuberculosis-associated immune reconstitution inflammatory syndrome

BACKGROUND

Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is a substantial problem in HIV/TB coinfected patients commencing antiretroviral therapy (ART). The immunopathogenesis of TB-IRIS includes increased production of proinflammatory chemokines and cytokines, including interleukin-18, which is a signature cytokine of the nucleotide-binding domain and leucine-rich repeat pyrin containing protein-3 inflammasome. We compared plasma levels of interleukin-18 and other biomarkers of monocyte/macrophage activation in the prediction and characterization of TB-IRIS.

METHODS

Biomarkers were assayed pre-ART and during TB-IRIS, or equivalent time-point, in a case-control study of Malaysian HIV patients with paradoxical or unmasking TB-IRIS (n = 15), TB no IRIS (n = 14), and no TB or IRIS (n = 15). Findings for interleukin-18 were verified in another cohort of patients with paradoxical TB-IRIS (n = 26) and their controls (n = 22) from India.

RESULTS

Interleukin-18 was higher in TB-IRIS patients pre-ART and during the event in both Malaysian patients (P < 0.0001) and Indian patients (P < 0.01). CXCL10 was higher pre-ART (P < 0.001), mainly in paradoxical TB-IRIS patients, and during TB-IRIS (P < 0.001), whereas CXCL8 was only higher during TB-IRIS (P < 0.001). Soluble(s) CD14 was increased in all patients with HIV/TB coinfection pre-ART and during TB-IRIS or equivalent time-point, compared with patients without TB. In contrast, interferon-γ was lower before and during TB-IRIS. By receiver operating curve analysis, CXCL10, and/or interleukin-18 pre-ART were predictive of TB-IRIS.

CONCLUSION

Plasma interleukin-18 levels pre-ART are candidate biomarkers for predicting paradoxical and unmasking TB-IRIS and should be investigated for risk stratification and elucidation of disease pathogenesis.

Effect of the CCR5 antagonist maraviroc on the occurrence of immune reconstitution inflammatory syndrome in HIV (CADIRIS): a double-blind, randomised, placebo-controlled trial

BACKGROUND

Immune reconstitution inflammatory syndrome (IRIS) is a common complication of antiretroviral therapy (ART) in patients with HIV. IRIS is associated with an increased risk of admission to hospital and death. We assessed whether CCR5 blockade with maraviroc reduces the risk of IRIS.

METHODS

The CADIRIS study was a double-blind, randomised, placebo-controlled trial that recruited participants from five clinical sites in Mexico and one in South Africa and followed them for 1 year. Patients were eligible if they were adults with HIV, who were naive to ART, had CD4 count lower than 100 cells per μL and HIV RNA greater than 1000 copies per mL. Participants were randomly assigned (1:1) by permuted block randomisation to receive either maraviroc (600 mg twice daily) or placebo in addition to an ART regimen that included tenofovir, emtricitabine, and efavirenz for 48 weeks. Patients, care providers, and members of the research team were masked to treatment allocation. Clinical and laboratory evaluations were done at baseline, and weeks 2, 4, 8, 12, 16, 24, 48, and 60. The primary outcome was time to an IRIS event by 24 weeks. All patients who were randomly assigned contributed to the primary time-to-event analysis from the date of ART initiation until week 24, the time of an IRIS event or death. This trial is registered with ClinicalTrials.gov, number NCT00988780.

FINDINGS

Between Dec 10, 2009, and Jan 17, 2012, we screened 362 patients; of whom 279 met the inclusion criteria and three refused to participate; thus 276 participants were randomly assigned (140 to receive maraviroc and 136 to receive placebo). 64 (23%) patients had IRIS events, 33 (24%) in the maraviroc group and 31 (23%) in the placebo group (p=0·74). No difference in the time to IRIS events was noted between the treatment groups (HR 1·08, 95% CI 0·66-1·77; log-rank test p=0·74). 37 participants (26%) in the maraviroc group had grade 3 or 4 adverse events compared with 24 (18%) in placebo group; p=0·072); 25 (18%) in the maraviroc group and 21 (15%) in the placebo group had serious treatment emergent adverse events (p=0·63).

INTERPRETATION

Maraviroc had no significant effect on development of IRIS after ART initiation. Inclusion of this CCR5 inhibitor in an initial treatment regimen does not confer a meaningful protection from the occurrence of IRIS in people with advanced HIV infection.

FUNDING

Pfizer.