Case report. Recurrence of increased intracranial pressure with antiretroviral therapy in an AIDS patient with cryptococcal meningitis

Cerebellitis associated with cryptococcal-immune reconstitution inflammatory syndrome

Cerebellitis associated with cryptococcal immune reconstitution inflammatory syndrome (IRIS) has not been previously reported. We describe a unique case of IRIS associated cerebellitis in an AIDS patient with cryptococcosis.

Ischemic stroke as a complication of cryptococcal meningitis and immune reconstitution inflammatory syndrome: a case report

Background

Cryptococcal meningitis remains the leading cause of adult meningitis in Sub-Saharan Africa. Immune Reconstitution Inflammatory Syndrome (IRIS) following anti-retroviral therapy (ART) initiation is an important complication. Here we report the first documented case of a IRIS reaction presenting as an ischemic stroke.

Case presentation

A 38 year old newly diagnosed HIV-infected, ART naive Malawian male presented to a tertiary referral hospital in Blantyre, Malawi with a 2 week history of headache. A diagnosis of cryptococcal meningitis was made and the patient was started on 1200 mg fluconazole once daily and flucytosine 25 mg/kg four times daily as part of the Advancing Cryptococcal Treatment for Africa (ACTA) clinical trial. There was an initial clinical and microbiological response to anti-fungal treatment and anti-retroviral therapy was started at week 4. The patient re-presented 16 days later with recurrence of headache, fever, and a sudden onset of left sided weakness in the context of rapid immune reconstitution; peripheral CD4 count had increased from a baseline of 29 cells/μl to 198 cells/μl. Recurrence of cryptococcal meningitis was excluded through CSF examination and fungal culture. Magnetic Resonance Imaging (MRI) of the brain demonstrated multi-focal DWI (diffusion weighted imaging) positive lesions consistent with an ischemic stroke. Given the temporal relationship to ART initiation, these MRI findings in the context of sterile CSF with raised CSF protein and a rapid immune reconstitution, following an earlier favorable response to treatment is most consistent with a paradoxical Immune Reconstitution Inflammatory Syndrome.

Conclusions

Stroke is an increasing cause of morbidity and mortality amongst HIV infected persons. Ischemic stroke is a recognized complication of cryptococcal meningitis in the acute phase and is thought to be mediated by an infectious vasculitis. This is the first time an ischemic stroke has been described as part of a paradoxical IRIS reaction. This report adds to the spectrum of clinical IRIS presentations recognized and highlights to clinicians the potential complications encountered at ART initiation in severely immunocompromised patients.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3386-0) contains supplementary material, which is available to authorized users.

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.

Persistent Cryptococcal Brain Infection despite Prolonged Immunorecovery in an HIV-Positive Patient

Background. HIV-positive people starting combined antiretroviral therapy may develop immune reconstitution to latent or treated opportunistic infections. Immune reconstitution to cerebral Cryptococcus is poorly understood and can be fatal. Case Presentation. A 33-year-old Zimbabwean female presented with cryptococcal meningitis and newly diagnosed HIV with a CD4 count of 51 cells/μL (4%). She was treated with amphotericin and flucytosine. Combined antiretroviral therapy was started four weeks later and she showed early improvement. However, over the ensuing 18 months, her clinical course was marked by periodic worsening with symptoms resembling cryptococcal meningitis despite having achieved CD4 counts ≥400 cells/μL. Although initially treated for relapsing cryptococcal immune reconstitution syndrome, a brain biopsy taken 17 months after initial presentation showed budding Cryptococci. Conclusion. This unusually protracted case highlights the difficulties in differentiating relapsing cryptococcal meningitis from immune reconstitution and raises questions concerning the optimum timing of initiation of combined antiretroviral therapy in such patients.

New Insights into HIV/AIDS-Associated Cryptococcosis

Cryptococcal meningitis is a life-threatening opportunistic fungal infection in both HIV-infected and HIV-uninfected patients. According to the most recent taxonomy, the responsible fungus is classified into a complex that contains two species (Cryptococcus neoformans and C. gattii), with eight major molecular types. HIV infection is recognized worldwide as the main underlying disease responsible for the development of cryptococcal meningitis (accounting for 80-90% of cases). In several areas of sub-Saharan Africa with the highest HIV prevalence despite the recent expansion of antiretroviral (ARV) therapy programme, cryptococcal meningitis is the leading cause of community-acquired meningitis with a high mortality burden. Although cryptococcal meningitis should be considered a neglected disease, a large body of knowledge has been developed by several studies performed in recent years. This paper will focus especially on new clinical aspects such as immune reconstitution inflammatory syndrome, advances on management, and strategies for the prevention of clinical disease.

Diagnosis and Management of Cryptococcal Relapse

Despite improvements in the antifungal regimens and the roll out of antiretroviral therapy (ART) in sub-Saharan Africa, mortality due to cryptococcal meningitis remains high. Relapse of an initially successfully treated infection contributes to this mortality and is often a clinical dilemma in differentiating between paradoxical immune reconstitution inflammatory syndrome (IRIS) and culture-positive relapse or treatment failure. Herein, we present a clinical case scenario and review the case definitions, differential diagnosis, and management of relapse with an emphasis on the current diagnostic and management strategies. We also highlight the challenges of resistance testing and management of refractory relapse cases. The risk of relapse is influenced by: 1) the choice of induction therapy, with higher mortality risk with fluconazole monotherapy which can select for resistance; 2) non-adherence to or lack of secondary prophylaxis; 3) failure of linkage-to-care or retention-in-care of HIV ART programs.

Central Nervous System Strongyloidiasis and Cryptococcosis in an HIV-Infected Patient Starting Antiretroviral Therapy

We report a case of Strongyloides stercoralis hyperinfection syndrome with central nervous system involvement, in a patient with late human immunodeficiency virus (HIV) infection starting antiretroviral therapy, in whom Strongyloides stercoralis larvae and Cryptococcus neoformans were isolated antemortem from cerebrospinal fluid. Our patient was not from an endemic region for the parasite, so strongyloidiasis was not originally suspected. For this reason, we conclude that Strongyloides stercoralis infection should be suspected in HIV-infected patients starting antiretroviral therapy in order to avoid potential fatal outcomes.

Cryptococcal immune reconstitution inflammatory syndrome in HIV-1-infected individuals: proposed clinical case definitions

Cryptococcal immune reconstitution inflammatory syndrome (IRIS) may present as a clinical worsening or new presentation of cryptococcal disease after initiation of antiretroviral therapy (ART), and is thought to be caused by recovery of cryptococcus-specific immune responses. We have reviewed reports of cryptococcal IRIS and have developed a consensus case definition specifically for paradoxical crytopcoccal IRIS in patients with HIV-1 and known cryptococcal disease before ART, and a separate definition for incident cryptococcosis developed during ART (termed ART-associated cryptococcosis), for which a proportion of cases are likely to be unmasking cryptococcal IRIS. These structured case definitions are intended to aid design of future clinical, epidemiological, and immunopathological studies of cryptococcal IRIS, to standardise diagnostic criteria, and to facilitate comparisons between studies. As for definitions of tuberculosis-associated IRIS, definitions for cryptococcal IRIS should be regarded as preliminary until further insights into the immunopathology of IRIS permit their refinement.

Immune reconstitution inflammatory syndrome (IRIS) associated with Cryptococcus neoformans infection in AIDS patients

Cryptococcosis is frequently associated to the immune reconstitution inflammatory syndrome (IRIS) in AIDS patients on highly active antiretroviral therapy (HAART). This study aimed to evaluate clinical and evolutive features of IRIS associated cryptococcosis patients in Uberaba, Brazil.

PATIENTS

Eighty-one AIDS individuals admitted at the teaching hospital with cryptococcal meningitis were evaluated and from these, 40 were prospectively followed. Of 40 patients with cryptococcosis, nine (22.5%) presented clinical and laboratory features of IRIS. Six (66.6%) were male, with a mean age of 37.2. Five (55.5%) presented cryptococcosis as first AIDS defining condition. In seven (77.9%) IRIS was characterised as a relapse of meningeal symptoms after 10 weeks, mean time of 72 days, of starting HAART whereas, two asymptomatic patients developed the syndrome as an unmasked cryptococcosis after 10 and 12 weeks on HAART. Lymphadenitis as isolated finding associated with IRIS was evidenced in three cases. All patients presented low CD4(+) and high RNA viral load baseline values. Cultures of cerebrospinal fluid and lymph-node fragments tissues of these cases were negative. Six of nine individuals developed high intracranial pressure requiring a daily relief lumbar puncture. No deaths occurred during the evolution of these patients. The incidence and clinical evolutive profile observed in this case series are in accordance with other reports elsewhere.

Central nervous system cryptococcosis in solid organ transplant recipients: clinical relevance of abnormal neuroimaging findings

BACKGROUND

Prognostic implications of cryptococcal antigen and outcomes associated with central nervous system (CNS) cryptococcal lesions in solid organ transplant recipients have not been fully defined.

METHODS

Patients were derived form a cohort of 122 solid organ transplant recipients with cryptococcosis in a multicenter study from 1999 to 2006.

RESULTS

Central nervous system cryptococcosis was documented in 61 patients. Serum or cerebral spinal fluid antigen titers did not correlate with mortality at 90 days or cerebral spinal fluid sterilization at 2 weeks. Central nervous system lesions were identified in 16 patients and included leptomeningeal lesions in eight, parenchymal lesions in six, and hydrocephalus in two. Overall, 13/16 CNS lesions were present at the time of diagnosis. One parenchymal and two hydrocephalus lesions, however, developed after diagnosis and fulfilled the criteria for immune reconstitution syndrome. Cerebral spinal fluid antigen titers were higher with meningeal versus parenchymal lesions, and hydrocephalus (P=0.015). Mortality was 50% (3/6) for patients with parenchymal, 12.5% (1/8) for those with leptomeningeal, and 0/3 for patients with hydrocephalus. Mortality was 31% (4/13) for patients with CNS lesions at baseline and 0/3 in those with new onset lesions.

CONCLUSIONS

Despite a higher antigen titer with meningeal lesions, outcomes tended to be worse with parenchymal compared with meningeal lesions or hydrocephalus. New onset CNS lesions may represent immune reconstitution syndrome and seemed to be associated with better outcome.

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.

Immune reconstitution syndrome associated with opportunistic mycoses

Host immunity is essential in facilitating the eradication of infection. However, immunological recovery and an imbalance characterised by either suboptimum or excessive expression of immune responses can also be harmful to the host. Inflammatory responses triggered by rapid resolution of immunosuppression can lead to a series of localised and systemic reactions, termed immune reconstitution syndrome (IRS), that are often misconstrued as failure of specific antifungal therapy to eliminate the offending fungal pathogen. Recognition of IRS has become increasingly relevant in the context of our current use of potent immunosuppressive agents and immunostimulators that allow rapid manipulation of the immune system. Whereas the conceptual principles of IRS underscore the adverse effects of an overzealous and dysregulated immune response, they also support a role of immunotherapies to augment immunity if induction of endogenous responses is inadequate for the control of infection.

Immune reconstitution inflammatory syndrome (IRIS): review of common infectious manifestations and treatment options

The immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients initiating antiretroviral therapy (ART) results from restored immunity to specific infectious or non-infectious antigens. A paradoxical clinical worsening of a known condition or the appearance of a new condition after initiating therapy characterizes the syndrome. Potential mechanisms for the syndrome include a partial recovery of the immune system or exuberant host immunological responses to antigenic stimuli. The overall incidence of IRIS is unknown, but is dependent on the population studied and its underlying opportunistic infectious burden. The infectious pathogens most frequently implicated in the syndrome are mycobacteria, varicella zoster, herpesviruses, and cytomegalovirus (CMV). No single treatment option exists and depends on the underlying infectious agent and its clinical presentation. Prospective cohort studies addressing the optimal screening and treatment of opportunistic infections in patients eligible for ART are currently being conducted. These studies will provide evidence for the development of treatment guidelines in order to reduce the burden of IRIS. We review the available literature on the pathogenesis and epidemiology of IRIS, and present treatment options for the more common infectious manifestations of this diverse syndrome and for manifestations associated with a high morbidity.

Cryptococcal immune reconstitution inflammatory syndrome: report of four cases in three patients and review of the literature

Immune reconstitution inflammatory syndromes (IRIS) in patients with AIDS are characterized by atypical manifestations of opportunistic pathogens in patients experiencing improvement in CD4 cell counts following receipt of highly active anti-retroviral therapy (HAART). We report four cases of IRIS due to Cryptococcus neoformans in three patients and review the literature of cryptococcal IRIS in AIDS (an additional 21 episodes). The IRIS presentation was lymphadenitis in all three patients; one patient also had meningeal IRIS. Combining our patients with the literature review revealed the following IRIS presentations: lymphadenitis (n=14), central nervous system (CNS) IRIS (n=10): meningitis in six and mass lesions in four, and pulmonary cavities (n=1). The median CD4 count of cases at the time of initial cryptococcal diagnosis and prior to the start of HAART was 25 cells/microl and the median HIV viral load was 439,053 copies/ml. At time of presentation of the IRIS, the median CD4 count had increased by 197 cells/microl. The median time from initial cryptococcal diagnosis and the start of HAART to the IRIS was 11 months (range 7 weeks to 3 years) and 7 months (range <2 weeks to 22 months), respectively. Patients with CNS IRIS tended to have shorter intervals from initiation of HAART to presentation compared to patients with lymphadenitis: median 3.5 months compared to 7 months. In 24 of 25 cases, the clinical manifestations of the IRIS resolved (range: days to months). Only four patients were given anti-inflammatory medications: corticosteroids in two and non-steroidal anti-inflammatory drugs in two, thus precluding assessment of efficacy. Patients with cryptococcal disease who initiate HAART are at risk for cryptococcal IRIS.

Incidence and risk factors of immune reconstitution inflammatory syndrome complicating HIV-associated cryptococcosis in France

BACKGROUND

Immune reconstitution inflammatory syndrome (IRIS) in association with cryptococcosis has been anecdotically reported following administration of highly active antiretroviral therapy (HAART).

OBJECTIVE

To analyse the incidence and risk factors for IRIS-associated cryptococcosis among HIV-infected patients.

DESIGN

Retrospective multicentre study between 1996 and 2000 through the French Cryptococcosis Database.

METHODS

Subsequent occurrence of IRIS examined in 120 HIV-infected adult patients treated with HAART and experiencing a first episode of culture-confirmed cryptococcosis.

RESULTS

Ten patients developed IRIS during the study period, giving an incidence of 10/239, or 4.2/100 person-years [95% confidence interval (CI), 2.2-7.8]. IRIS consisted of acute symptoms consistent with inflammation occurring within a median of 8 months (range, 2-37) after the diagnosis of cryptococcosis in the context of negative cultures and immunological and/or virological response to HAART. Radiology and histopathology detected features compatible with inflammation. Symptom severity required transfer into intensive care units for three patients and use of anti-inflammatory drugs for four. Three patients with evolutive IRIS died. Compared with patients without IRIS for whom complete clinical and microbiological information were available at baseline, previously unknown HIV infection [odds ratio (OR), 4.8; 95% CI, 1.0-21.7], CD4 cell count < 7 x 10 cells/l (OR, 4.0; 95% CI, 0.9-17.2), fungaemia (OR, 6.1; 95% CI, 1.1-35.2) and HAART initiation within 2 months of cryptococcosis diagnosis (OR, 5.50; 95% CI, 1.0-29.6) were independently associated with the risk of subsequent IRIS.

CONCLUSIONS

IRIS-related cryptococcosis was observed more frequently in severely immunocompromised patients with disseminated infection and HAART initiation soon after the diagnosis.

Incidence and risk factors for immune reconstitution inflammatory syndrome during highly active antiretroviral therapy

BACKGROUND

There is little systematic information regarding the immune reconstitution inflammatory syndrome (IRIS).

OBJECTIVE

To determine the incidence, risk factors, and long-term outcome of IRIS in HIV-infected patients receiving highly active antiretroviral therapy (HAART) who were coinfected with one of three common opportunistic pathogens.

DESIGN

A retrospective cohort identified through a city-wide prospective surveillance program.

METHODS

A retrospective chart review was performed for 180 HIV-infected patients who received HAART and were coinfected with Mycobacterium tuberculosis, Mycobacterium avium complex, or Cryptococcus neoformans between 1997 and 2000. Medical records were reviewed for baseline demographics, receipt and type of HAART, response to antiretroviral therapy, development of IRIS, and long-term outcome.

RESULTS

In this cohort, 31.7% of patients who received HAART developed IRIS. Patients with IRIS were more likely to have initiated HAART nearer to the time of diagnosis of their opportunistic infection (P < 0.001), to have been antiretroviral naive at time of diagnosis of their opportunistic infection (P < 0.001), and to have a more rapid initial fall in HIV-1 RNA level in response to HAART (P < 0.001).

CONCLUSIONS

IRIS is common among HIV-infected persons coinfected with M. tuberculosis, M. avium complex, or C. neoformans. Antiretroviral drug-naive patients who start HAART in close proximity to the diagnosis of an opportunistic infection and have a rapid decline in HIV-1 RNA level should be monitored for development of this disorder.

Illness of immune reconstitution: Recognition and management

Some individuals who initiate highly active antiretroviral therapy (HAART) develop new or worsening opportunistic infections or malignancies despite improvements in surrogate markers of HIV-1 infection. These events of paradoxical clinical worsening, also known as immune reconstitution syndromes (IRS), are increased in individuals with prior opportunistic infections or low CD4+ T-cell nadirs. They are thought to result from reconstitution of the immune system's ability to recognize pathogens or tumor antigens that were previously present, but clinically asymptomatic. There is no consensus regarding the diagnostic criteria or pathogenesis of IRS. Knowledge of their presentation and treatment is largely based on case reports. With the introduction of HAART into resource-limited settings, it is likely that significantly more and distinct forms of IRS will be observed. Prospective studies of the incidence and treatment of IRS in multiple settings are critical to better understand their pathogenesis and optimal management.

Immune restoration disease after antiretroviral therapy

Suppression of HIV replication by highly active antiretroviral therapy (HAART) often restores protective pathogen-specific immune responses, but in some patients the restored immune response is immunopathological and causes disease [immune restoration disease (IRD)]. Infections by mycobacteria, cryptococci, herpesviruses, hepatitis B and C virus, and JC virus are the most common pathogens associated with infectious IRD. Sarcoid IRD and autoimmune IRD occur less commonly. Infectious IRD presenting during the first 3 months of therapy appears to reflect an immune response against an active (often quiescent) infection by opportunistic pathogens whereas late IRD may result from an immune response against the antigens of non-viable pathogens. Data on the immunopathogenesis of IRD is limited but it suggests that immunopathogenic mechanisms are determined by the pathogen. For example, mycobacterial IRD is associated with delayed-type hypersensitivity responses to mycobacterial antigens whereas there is evidence of a CD8 T-cell response in herpesvirus IRD. Furthermore, the association of different cytokine gene polymorphisms with mycobacterial or herpesvirus IRD provides evidence of different pathogenic mechanisms as well as indicating a genetic susceptibility to IRD. Differentiation of IRD from an opportunistic infection is important because IRD indicates a successful, albeit undesirable, effect of HAART. It is also important to differentiate IRD from drug toxicity to avoid unnecessary cessation of HAART. The management of IRD often requires the use of anti-microbial and/or anti-inflammatory therapy. Investigation of strategies to prevent IRD is a priority, particularly in developing countries, and requires the development of risk assessment methods and diagnostic criteria.

Immune reconstitution cryptococcosis after initiation of successful highly active antiretroviral therapy

Five of 10 patients who commenced successful highly active antiretroviral therapy (HAART) for infection with human immunodeficiency virus type 1 (HIV-1) concurrent with or soon after a diagnosis of cryptococcal infection experienced clinical events characterized by sterile inflammation. Two patients developed aseptic meningitis with elevated intracranial pressure, 1 developed intrathoracic lyphadenopathy with hypercalcemia, 1 developed cavitary pneumonia at the site of a cryptococcal nodule, and 1 developed a supraclavicular abscess. These events occurred 2-11 months after initiation of HAART. For 3 patients, biopsy demonstrated findings atypical for acquired immunodeficiency syndrome-associated cryptococcosis. Results of fungal cultures were negative for all 5 patients, and cryptococcal antigen levels had declined markedly in 4 patients. The timing and clinical features of and biopsy findings for these cases of cryptococcosis suggest the existence of a paradoxical reaction to Cryptococcus infection that occurs in the context of HIV immune restoration.