Immune reconstitution inflammatory syndrome in HIV-infected patients

Opinion: Paracoccidioidomycosis and HIV Immune Recovery Inflammatory Syndrome

Two distinct patterns of immune recovery inflammatory syndrome (IRIS) are recognized, paradoxical and unmasking IRIS. Here we raise some concerns regarding the first case of neuroPCM-IRIS published to date, as recently proposed by Almeida and Roza (Mycopathologia 177:137-141, 2017) for a patient originally described by Silva-Vergara et al. (Mycopathologia 182:393-396, 2014), taking in account the different case definitions for IRIS and the cases of neuroparacoccidioidomycosis already described in the literature. We are concerned that data from the case report have been misinterpreted and that no regard has been given to the possibility that the development of manifestations of neuroPCM after starting antiretroviral therapy and antifungal treatments could represent the predicted course of a missed neuroPCM diagnosis at presentation whose treatment failed. We hypothesize that diagnosis of the neuroPCM would not have been missed if careful screening for opportunistic infection of the central nervous system was performed prior to antiretroviral therapy initiation. Currently, there is no definitive diagnostic test for IRIS and diagnostic suspicion, as well as its management, are based on image studies and non-specific clinical signs and symptoms of inflammation. IRIS remains a diagnosis of exclusion, after considering drug toxicity, microbiologic treatment failure and the expected course of newly or previously diagnosed opportunistic infections.

Interventions for Neurocognitive Dysfunction

PURPOSE OF REVIEW

This study aimed to evaluate current barriers to HIV cure strategies and interventions for neurocognitive dysfunction with a particular focus on recent advancements over the last 3 years.

RECENT FINDINGS

Optimal anti-retroviral therapy (ART) poses challenges to minimise neurotoxicity, whilst ensuring blood-brain barrier penetration and minimising the risk of cerebrovascular disease. CSF biomarkers, BCL11B and neurofilament light chain may be implicated with a neuroinflammatory cascade leading to cognitive impairment. Diagnostic imaging with diffusion tensor imaging and resting-state fMRI show promise in future diagnosis and monitoring of HAND. The introduction of ART has resulted in a dramatic decline in HIV-associated dementia. Despite this reduction, milder forms of HIV-associated neurocognitive disorder (HAND) are still prevalent and are clinically significant. The central nervous system (CNS) has been recognised as a probable reservoir and sanctuary for HIV, representing a significant barrier to management interventions.

Immune Reconstitution Inflammatory Syndrome and Cytomegalovirus Pneumonia Case Report: Highlights and Missing Links in Classification Criteria and Standardized Treatment

BACKGROUND

Cytomegalovirus (CMV) pulmonary involvement is rarely associated with IRIS; therefore, limited information is available.

CASE PRESENTATION

Here, we describe the case of a 43-year-old HIV-infected male who developed an unusual case of IRIS after cytomegalovirus (CMV) pneumonia. Clinically there was a progressive and paradoxical worsening of respiratory distress, despite being treated for CMV after initiation with antiretroviral therapy. Chest X-ray revealed disseminated infiltrates in both lungs; chest CT-scan showed generalized lung involvement and mediastinal adenopathy. Pulmonary biopsy confirmed CMV pneumonia with the observation of typical viral inclusions on pneumocytes.

CONCLUSIONS

CMV pneumonia can be associated with the development of IRIS requiring treatment with immunosuppressant's and immunomodulatory drugs.

Cryptococcal antigen screening by lay cadres using a rapid test at the point of care: A feasibility study in rural Lesotho

INTRODUCTION

Cryptococcal meningitis is one of the leading causes of death among people with HIV in Africa, primarily due to delayed presentation, poor availability and high cost of treatment. Routine cryptococcal antigen (CrAg) screening of patients with a CD4 count less than 100 cells/mm3, followed by pre-emptive therapy if positive, might reduce mortality in high prevalence settings. Using the cryptococcal antigen (CrAg) lateral flow assay (LFA), screening is possible at the point of care (POC). However, critical shortages of health staff may limit adoption. This study investigates the feasibility of lay counsellors conducting CrAg LFA screening in rural primary care clinics in Lesotho.

METHODS

From May 2014 to June 2015, individuals who tested positive for HIV were tested for CD4 count and those with CD4 <100 cells/mm3 were screened with CrAg LFA. All tests were performed by lay counsellors. CrAg-positive asymptomatic patients received fluconazole, while symptomatic patients were referred to hospital. Lay counsellors were trained and supervised by a laboratory technician and counsellor activity supervisor. Additionally, nurses and doctors were trained on CrAg screening and appropriate treatment.

RESULTS

During the study period, 1,388 people were newly diagnosed with HIV, of whom 129 (9%) presented with a CD4 count <100 cells/mm3. Of these, 128 (99%) were screened with CrAg LFA and 14/128 (11%) tested positive. Twelve of the 14 (86%) were asymptomatic, and received outpatient fluconazole. All commenced ART with a median time to initiation of 15.5 days [IQR: 14-22]. Of the asymptomatic patients, nine (75%) remained asymptomatic after a median time of 5 months [IQR; 3-6] of follow up. One (8%) became co-infected with tuberculosis and died and two were transferred out. The two patients with symptomatic cryptococcal meningitis (CM) were referred to hospital, where they later died.

CONCLUSIONS

CrAg LFA screening by lay counsellors followed by pre-emptive fluconazole treatment for asymptomatic cases, or referral to hospital for symptomatic cases, proved feasible. However, regular follow-up to ensure proper management of cryptococcal disease was needed. These early results support the wider use of CrAg LFA screening in remote primary care settings where upper cadres of healthcare staff may be in short supply.

Matrix Degradation in Human Immunodeficiency Virus Type 1-Associated Tuberculosis and Tuberculosis Immune Reconstitution Inflammatory Syndrome: A Prospective Observational Study

Background

Extensive immunopathology occurs in human immunodeficiency virus (HIV)/tuberculosis (TB) coinfection, but the underlying molecular mechanisms are not well-defined. Excessive matrix metalloproteinase (MMP) activity is emerging as a key process but has not been systematically studied in HIV-associated TB.

Methods

We performed a cross-sectional study of matrix turnover in HIV type 1 (HIV-1)-infected and -uninfected TB patients and controls, and a prospective cohort study of HIV-1-infected TB patients at risk of TB immune reconstitution inflammatory syndrome (TB-IRIS), in Cape Town, South Africa. Sputum and plasma MMP concentrations were quantified by Luminex, plasma procollagen III N-terminal propeptide (PIIINP) by enzyme-linked immunosorbent assay, and urinary lipoarabinomannan (LAM) by Alere Determine TB LAM assay. Peripheral blood mononuclear cells from healthy donors were cultured with Mycobacterium tuberculosis and extracellular matrix in a 3D model of TB granuloma formation.

Results

MMP activity differed between HIV-1-infected and -uninfected TB patients and corresponded with specific TB clinical phenotypes. HIV-1-infected TB patients had reduced pulmonary MMP concentrations, associated with reduced cavitation, but increased plasma PIIINP, compared to HIV-1-uninfected TB patients. Elevated extrapulmonary extracellular matrix turnover was associated with TB-IRIS, both before and during TB-IRIS onset. The predominant collagenase was MMP-8, which was likely neutrophil derived and M. tuberculosis-antigen driven. Mycobacterium tuberculosis-induced matrix degradation was suppressed by the MMP inhibitor doxycycline in vitro.

Conclusions

MMP activity in TB differs by HIV-1 status and compartment, and releases matrix degradation products. Matrix turnover in HIV-1-infected patients is increased before and during TB-IRIS, informing novel diagnostic strategies. MMP inhibition is a potential host-directed therapy strategy for prevention and treatment of TB-IRIS.

Hospital days attributable to immune reconstitution inflammatory syndrome in persons living with HIV before and after the 2012 DHHS HIV guidelines

Background

Immune reconstitution inflammatory syndrome (IRIS) can manifest with initiation or reintroduction of antiretroviral therapy (ART) in persons living with HIV (PLWH). In 2012, updated United States treatment guidelines recommended initiation of ART for all PLWH regardless of CD4 count. The objectives of this study were to quantify hospital usage attributable to IRIS and assess the reasons for hospitalization in PLWH before and after the guideline update.

Methods

Subjects were PLWH between 18–89 years of age who were hospitalized between November 1, 2009 and July 31, 2014. Equivalent time periods before and after updated treatment guidelines were considered, and designated as Time Period 1 and Time Period 2, respectively. IRIS-attributable hospitalizations were identified by ICD9 codes and electronic medical record searches with subsequent review and confirmation. For hospitalizations that were not confirmed as being IRIS-attributable, primary discharge diagnoses were reviewed.

Results

A total of 278 PLWH were hospitalized 521 times throughout the study period. Time Period 1 had 9 PLWH with 12 IRIS-attributable hospitalizations while Time Period 2 had 6 PLWH with 9 IRIS-attributable hospitalizations. A larger proportion of IRIS-attributable hospital days was observed in Time Period 1 compared to Time Period 2 (7.5 vs 4.2%; p < 0.001). Median length of stay for IRIS-attributable hospitalizations was longer than for other diagnoses, particularly during Time Period 1 (12.0 vs 4.0; p = 0.05). The most common causes for hospitalizations in PLWH were non AIDS-defining infection, AIDS-defining malignancy, and gastrointestinal. PLWH who had HIV viral suppression (<200 copies/mL) accounted for 34 and 24% of hospitalizations in Time Periods 1 and 2 respectively.

Conclusions

Hospitalizations for PLWH continue at high rates and IRIS is a significant contributing factor. In our single-center study, there was a lower number of IRIS-attributable hospitalizations and IRIS-attributable hospital days in Time Period 2 compared with Time Period 1. The hospital burden of IRIS may decrease over time as more PLWH are started on ART earlier in the course of infection. This study highlights the continued importance of early diagnosis and linkage to care of those infected with HIV, so that morbidity and costs associated with IRIS continue to decline.

The Epidemiology of IRIS in Southern India: An Observational Cohort Study

Immune reconstitution inflammatory syndrome (IRIS) is an uncommon but dynamic phenomenon seen among patients initiating antiretroviral therapy (ART). We aimed to describe incidence, risk factors, clinical spectrum, and outcomes among ART-naive patients experiencing IRIS in southern India. Among 599 eligible patients monitored prospectively between 2012 and 2014, there were 59.3% males, with mean age 36.6 ± 7.8 years. Immune reconstitution inflammatory syndrome incidence rate was 51.3 per 100 person-years (95% confidence interval: 44.5-59.2). One-third (31.4%) experienced at least 1 IRIS event, at a median of 27 days since ART initiation. Mucocutaneous infections and candidiasis were common IRIS events, followed by tuberculosis. Significant risk factors included age >40 years, body mass index <18.5 kg/m², CD4 count <100 cells/mm³, viral load >10 000 copies/mL, hemoglobin <11 g/dL, and erythrocyte sedimentation rate >50 mm/h. Immune reconstitution inflammatory syndrome-related morality was 1.3% (8 of 599); 3 patients died of complicated diarrhea. These findings highlight the current spectrum of IRIS in South India and underscore the importance of heightened vigilance for anemia and treatment of diarrhea and candidiasis during ART initiation.

Low incidence of the immune reconstitution inflammatory syndrome among HIV-infected patients starting antiretroviral therapy in Gabon: a prospective cohort study

There is a paucity of data on the immune reconstitution inflammatory syndrome (IRIS) in the Central African region. We followed ART-naive HIV-infected patients initiating antiretroviral therapy in an HIV clinic in Gabon, for 6 months. Among 101 patients, IRIS was diagnosed in five. All IRIS cases were mucocutaneous manifestations. There were no cases of tuberculosis (TB) IRIS, but active TB (n = 20) was associated with developing other forms of IRIS (p = 0.02). Six patients died. The incidence of IRIS is low in Gabon, with mild, mucocutaneous manifestations.

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: Opening Pandora's Box

One of the purposes of antiretroviral therapy (ART) is to restore the immune system. However, it can sometimes lead to an aberrant inflammatory response and paradoxical clinical worsening known as the immune reconstitution inflammatory syndrome (IRIS). We describe a 23-year-old male, HIV1 infected with a rapid progression phenotype, who started ART with TCD4+ of 53 cells/mm³ (3,3%) and HIV RNA = 890000 copies/mL (6 log). Four weeks later he was admitted to the intensive care unit with severe sepsis. The diagnostic pathway identified progressive multifocal leukoencephalopathy, digestive Kaposi sarcoma, and P. aeruginosa bacteraemia. Five weeks after starting ART, TCD4+ cell count was 259 cells/mm³ (15%) and HIV RNA = 3500 copies/mL (4 log). He developed respiratory failure and progressed to septic shock and death. Those complications might justify the outcome but its autopsy opened Pandora's box: cerebral and cardiac toxoplasmosis was identified, as well as hemophagocytic syndrome, systemic candidiasis, and Mycobacterium avium complex infection. IRIS remains a concern and eventually a barrier to ART. Male gender, young age, low TCD4 cell count, and high viral load are risk factors. The high prevalence of subclinical opportunistic diseases highlights the need for new strategies to reduce IRIS incidence.

Immune recovery uveitis in HIV patients with cytomegalovirus retinitis in the era of HAART therapy-a 5-year study from Singapore

Background

The aim of this study is to analyse the clinical features of HIV patients with cytomegalovirus retinitis (CMVR) developing immune recovery uveitis (IRU) while on highly active antiretroviral therapy (HAART) and to identify the risk factors, visual outcomes and complications of IRU.

Results

Majority (n = 26, 86.7 %) of patients were male, with 76.7 % (n = 23) of patients having bilateral disease. Twenty-seven eyes (50.9 %) had both anterior uveitis and vitritis. The median CD4 at IRU was 210 cells/μL (IQR 140–279), with 86.7 % having CD4 >100 cells/μL. The median duration from initiation of HAART to IRU was significantly different between those <50 years old (median 763 days, IQR 174–1872 days) and those ≥50 years old (median 161 days, IQR 84.5–278 days). Fourteen eyes (26.4 %) had loss of one or more Snellen lines visual acuity at 6 months while the rest maintained or improved vision. Complications developed in 21 eyes, with cataract (66.7 %), glaucoma and ocular hypertension (33.3 %) being the most common. The risk of complications was associated with the absolute difference in CD4 counts at IRU and at HAART commencement (p = 0.041). Age was also negatively associated with the duration from HAART to IRU (p = 0.005, Spearman’s rho coefficient = −0.503).

Conclusions

It is common to have both anterior uveitis and vitritis in IRU. There was a positive association between the increase in CD4 from HIV to IRU diagnoses and the risk of developing complications. Younger patients appeared to develop IRU later than older patients after HAART, suggesting that long-term follow-ups are essential for these patients.

The Risk of Hepatocellular Carcinoma After Directly Acting Antivirals for Hepatitis C Virus Treatment in Liver Transplanted Patients: Is It Real?

INTRODUCTION

Since directly acting antivirals (DAAs) for treatment of hepatitis C virus (HCV) were introduced, conflicting data emerged about the risk of hepatocellular carcinoma (HCC) after interferon (IFN)-free treatments. We present a case of recurrent, extra-hepatic HCC in a liver-transplanted patient soon after successful treatment with DAAs, along with a short review of literature.

CASE PRESENTATION

In 2010, a 53-year old man, affected by chronic HCV (genotype 1) infection and decompensated cirrhosis, underwent liver resection for HCC and subsequently received orthotopic liver transplantation. Then, HCV relapsed and, in 2013, he was treated with pegylated-IFN plus ribavirin; but response was null. In 2014, he was treated with daclatasvir plus simeprevir to reach sustained virological response. At baseline and at the end of HCV treatment, computed tomography (CT) scan of abdomen excluded any lesions suspected for HCC. However, alpha-fetoprotein was 2.9 ng/mL before DAAs, increasing up to 183.1 ng/mL at week-24 of follow-up after the completion of therapy. Therefore, CT scan of abdomen was performed again, showing two splenic HCC lesions.

CONCLUSIONS

Overall, nine studies have been published about the risk of HCC after DAAs. Patients with previous HCC should be carefully investigated to confirm complete HCC remission before starting, and proactive follow-up should be performed after DAA treatment.

Determinants of treatment-related paradoxical reactions during anti-tuberculosis therapy: a case control study

BACKGROUND

Inflammatory response following initial improvement with anti-tuberculosis (TB) treatment has been termed a paradoxical reaction (PR). HIV co-infection is a recognised risk, yet little is known about other predictors of PR, although some biochemical markers have appeared predictive. We report our findings in an ethnically diverse population of HIV-infected and uninfected adults.

METHODS

Prospective and retrospective clinical and laboratory data were collected on TB patients seen between January 1999-December 2008 at four UK centres selected to represent a wide ethnic and socio-economic mix of TB patients. Data on ethnicity and HIV status were obtained for all individuals. The associations between other potential risk factors and PR were assessed in a nested case-control study. All PR cases were matched two-to-one to controls by calendar time and centre.

RESULTS

Of 1817 TB patients, 82 (4.5 %, 95 % CI 3.6-5.5 %) were identified as having a PR event. The frequency of PR was 14.4 % (18/125; 95 % CI 8.2-20.6 %) and 3.8 % (64/1692; 2.9-4.7) for HIV-positive and HIV-negative individuals respectively. There were no differences observed in PR frequency according to ethnicity, although the site was more likely to be pulmonary in those of black and white ethnicity, and lymph node disease in those of Asian ethnicity. In multivariate analysis of the case-control cohort, HIV-positive patients had five times the odds of developing PR (aOR = 5.05; 95 % CI 1.28-19.85, p = 0.028), whilst other immunosuppression e.g. diabetes, significantly reduced the odds of PR (aOR = 0.01; 0.00-0.27, p = 0.002). Patients with positive TB culture had higher odds of developing PR (aOR = 6.87; 1.31-36.04, p = 0.045) compared to those with a negative culture or those in whom no material was sent for culture. Peripheral lymph node disease increased the odds of a PR over 60-fold 4(9.60-431.25, p < 0.001).

CONCLUSION

HIV was strongly associated with PR. The increased potential for PR in people with culture positive TB suggests that host mycobacterial burden might be relevant. The increased risk with TB lymphadenitis may in part arise from the visibility of clinical signs at this site. Non-HIV immunosuppression may have a protective effect. This study highlights the difficulties in predicting PR using routinely available demographic details, clinical symptoms or biochemical markers.

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.

Short Communication: Hyperthyroidism in Human Immunodeficiency Virus Patients on Combined Antiretroviral Therapy: Case Series and Literature Review

We describe an HIV-infected patient initiated on combined antiretroviral therapy (cART) who subsequently developed immune restoration disease (IRD) hyperthyroidism-this case represents one of five such patients seen at our center within the past year. Similar to previous reports of hyperthyroidism due to IRD, all of our patients experienced a rapid early recovery in total CD4 count, but developed symptoms of hyperthyroidism on average 3 years (38 months) after beginning cART, which represents a longer time frame than previously reported. Awareness and recognition of this potential complication of cART, which may occur years after treatment initiation, will allow patients with immune restorative hyperthyroidism to receive timely therapy and avoid the long-term complications associated with undiagnosed thyroid disease.

Longitudinal evaluation of regulatory T-cell dynamics on HIV-infected individuals during the first 2 years of therapy

Objectives:

A sizeable percentage of individuals infected by HIV and on antiretroviral therapy (ART) fail to increase their CD4⁺ T-cells to satisfactory levels. The percentage of regulatory T-cells (Tregs) has been suggested to contribute to this impairment. This study aimed to address this question and to expand the analysis of Tregs subpopulations during ART.

Design:

Longitudinal follow-up of 81 HIV-infected individuals during the first 24 months on ART.

Methods:

CD4⁺ T-cell counts, Tregs percentages, and specific Tregs subpopulations were evaluated at ART onset, 2, 6, 9, 12, 16, 20, and 24 months of ART (five individuals had no Tregs information at baseline).

Results:

The slope of CD4⁺ T-cell recovery was similar for individuals with moderate and with severe lymphopenia at ART onset. No evidence was found for a contribution of the baseline Tregs percentages on the CD4⁺ T-cell counts recovery throughout ART. In comparison to uninfected individuals, Tregs percentages were higher at ART onset only for patients with less than 200 cells/μl at baseline and decreased afterwards reaching normal values. Within Tregs, the percentage of naive cells remained low in these patients. Reduced thymic export and increased proliferation of Tregs vs. conventional CD4⁺ T cells might explain these persistent alterations.

Conclusion:

No effect of Tregs percentages at baseline was detected on CD4⁺ T-cell recovery. However, profound alterations on Tregs subpopulations were consistently observed throughout ART for patients with severe lymphopenia at ART onset.

Computational Analysis Reveals a Key Regulator of Cryptococcal Virulence and Determinant of Host Response

Cryptococcus neoformans is a ubiquitous, opportunistic fungal pathogen that kills over 600,000 people annually. Here, we report integrated computational and experimental investigations of the role and mechanisms of transcriptional regulation in cryptococcal infection. Major cryptococcal virulence traits include melanin production and the development of a large polysaccharide capsule upon host entry; shed capsule polysaccharides also impair host defenses. We found that both transcription and translation are required for capsule growth and that Usv101 is a master regulator of pathogenesis, regulating melanin production, capsule growth, and capsule shedding. It does this by directly regulating genes encoding glycoactive enzymes and genes encoding three other transcription factors that are essential for capsule growth: GAT201, RIM101, and SP1. Murine infection with cryptococci lacking Usv101 significantly alters the kinetics and pathogenesis of disease, with extended survival and, unexpectedly, death by pneumonia rather than meningitis. Our approaches and findings will inform studies of other pathogenic microbes.

Cryptococcus neoformans causes fatal meningitis in immunocompromised individuals, mainly HIV positive, killing over 600,000 each year. A unique feature of this yeast, which makes it particularly virulent, is its polysaccharide capsule; this structure impedes host efforts to combat infection. Capsule size and structure respond to environmental conditions, such as those encountered in an infected host. We have combined computational and experimental tools to elucidate capsule regulation, which we show primarily occurs at the transcriptional level. We also demonstrate that loss of a novel transcription factor alters virulence factor expression and host cell interactions, changing the lethal condition from meningitis to pneumonia with an exacerbated host response. We further demonstrate the relevant targets of regulation and kinetically map key regulatory and host interactions. Our work elucidates mechanisms of capsule regulation, provides methods and resources to the research community, and demonstrates an altered pathogenic outcome that resembles some human conditions.

Diagnosis of HIV-Associated Oral Lesions in Relation to Early versus Delayed Antiretroviral Therapy: Results from the CIPRA HT001 Trial

Oral mucosal lesions that are associated with HIV infection can play an important role in guiding the decision to initiate antiretroviral therapy (ART). The incidence of these lesions relative to the timing of ART initiation has not been well characterized. A randomized controlled clinical trial was conducted at the GHESKIO Center in Port-au-Prince, Haiti between 2004 and 2009. 816 HIV-infected ART-naïve participants with CD4 T cell counts between 200 and 350 cells/mm3 were randomized to either immediate ART initiation (early group; N = 408), or initiation when CD4 T cell count was less than or equal 200 cells/mm3 or with the development of an AIDS-defining condition (delayed group; N = 408). Every 3 months, all participants underwent an oral examination. The incidence of oral lesions was 4.10 in the early group and 17.85 in the delayed group (p-value <0.01). In comparison to the early group, there was a significantly higher incidence of candidiasis, hairy leukoplakia, herpes labialis, and recurrent herpes simplex in the delayed group. The incidence of oral warts in delayed group was 0.97 before therapy and 4.27 post-ART initiation (p-value <0.01). In the delayed group the incidence of oral warts post-ART initiation was significantly higher than that seen in the early group (4.27 versus 1.09; p-value <0.01). The incidence of oral warts increased after ART was initiated, and relative to the early group there was a four-fold increase in oral warts if ART was initiated following an AIDS diagnosis. Based upon our findings, candidiasis, hairy leukoplakia, herpes labialis, and recurrent herpes simplex indicate immune suppression and the need to start ART. In contrast, oral warts are a sign of immune reconstitution following ART initiation.

Severe Paradoxical Reaction During Treatment of Disseminated Tuberculosis in a Patient With Neutralizing Anti-IFNγ Autoantibodies

Interferon-gamma (IFNγ) neutralizing autoantibodies are associated with disseminated nontuberculous mycobacterial infections. We report a previously healthy Thai woman with disseminated tuberculosis and high-titer IFNγ-neutralizing autoantibodies, who developed a severe inflammatory reaction during anti-tuberculosis treatment. IFNγ contributes to host control of tuberculosis but appears inessential for tuberculosis paradoxical reactions.