Mediastinitis Due to Cryptococcal Infection: A New Clinical Entity in the HAART Era

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

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

Immune reconstitution inflammatory syndrome in HIV-associated cryptococcal meningitis: a prospective study

BACKGROUND

Prospective data on incidence, characteristics, and risk factors for cryptococcal meningitis immune reconstitution inflammatory syndrome (CM-IRIS) are lacking.

METHODS

Prospective study of 65 antiretroviral therapy (ART)-naive HIV-infected cryptococcal meningitis (CM) patients, who started ART after initiation of antifungal treatment. CM-IRIS definition: (1) cerebrospinal fluid (CSF) culture-confirmed CM, (2) symptom resolution before starting ART, (3) adherence to fluconazole and ART, (4) recurrence of CM symptoms after starting ART, (5) immunologic and/or virologic response to ART, (6) no alternative diagnosis.

RESULTS

ART was started at a median of 47 days from CM diagnosis. CM-IRIS developed in 11 of 65 (17%), at a median 29 days from starting ART. No factors at first CM episode (fungal burden, rate of clearance, CSF, or HIV parameters) predicted those at risk of CM-IRIS. At 6 months on ART, IRIS patients had greater CD4 rise from baseline (220 vs. 124 x 10 cells /L in non-IRIS, P = 0.01), and 4 of 11 CM-IRIS patients died compared with 14 of 54 non-IRIS patients (P = 0.5). For those developing CM-IRIS, CSF proinflammatory cytokines interferon gamma, tumour necrosis factor alpha, and interleukin 6, did not differ between first CM and CM-IRIS episode.

CONCLUSIONS

Patients with CM-IRIS had greater immune restoration in response to ART. Although common and potentially fatal, larger prospective studies are needed to determine whether CM-IRIS, in patients treated initially with amphotericin B, is associated with any increase in overall mortality.

Cryptococcal lymphadenitis as a manifestation of immune reconstitution inflammatory syndrome in an HIV-positive patient: a case report and review of the literature

Cryptococcus neoformans infections are typically associated with T-cell deficiencies, including acquired immunodeficiency syndrome (AIDS). Although highly active antiretroviral therapy (HAART) has strongly reduced AIDS-related opportunistic infections, the restoration and reactivation of CD4+ cells can induce an immune reconstitution inflammatory syndrome (IRIS), consisting in a deregulated inflammatory response to latent infectious pathogens and/or to their residual antigens. Cryptococcal lymphadenitis has occasionally been documented in IRIS. Here we report a case of histology- and culture-negative cryptococcal lymphadenitis associated with IRIS in an adult AIDS patient with a history of disseminated cryptococcosis, after the start of fully adherent HAART. Appropriate diagnosis was established on nested-PCR and sequence analysis of the interspacer region 2 of C. neoformans ribosomal DNA, and detection of slow-growing blastospores in enrichment cultures of fine-needle lymph node aspirate. Review of recent literature and our case findings suggest that IRIS-associated cryptococcal lymphadenitis is more likely the flare up of a latent infection rather than an immunopathological response to residual antigen of unviable cryptococci.

Therapy Insight: CNS manifestations of HIV-associated immune reconstitution inflammatory syndrome

The introduction of combination antiretroviral therapy for HIV infection has prolonged the lives of patients with AIDS. It is increasingly being recognized, however, that following initiation of this therapy some patients can develop a paradoxical neurological deterioration, despite dramatic improvements in HIV viral load and CD4+ T-cell counts. This immune reconstitution inflammatory syndrome (IRIS) in the CNS is emerging as an important neurological complication, particularly as antiretroviral therapy is now becoming readily available worldwide. Currently, there are no guidelines for prevention, diagnosis or treatment of the CNS manifestations of IRIS. Even in patients with an acute presentation, the diagnosis can be challenging. Furthermore, it is possible that more-chronic forms of the syndrome exist but remain unrecognized. Here, we review the various clinical presentations of CNS IRIS, and discuss options for their management.

Evidence base for using corticosteroids to treat HIV-associated immune reconstitution syndrome

Most of the evidence supporting the use of corticosteroids (steroids) for immune reconstitution syndrome (IRS) comes from case reports or retrospective series and is of low quality. However, when steroids are used, they have usually been associated with clinical improvement or resolution of IRS. Except in the case of hepatitis B- or C-associated IRS, there have been no reports of worsening of the IRS or adverse outcome due to steroid use. After ruling out other conditions which can mimic IRS, clinicians should strongly consider steroids when managing IRS associated with mycobacterial or fungal pathogens when there is severe disease, or when other measures have failed.

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.

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 Inflammatory Syndromes: The Dark Side of Successful Antiretroviral Treatment

The prevalence of cellular immunodeficiency has increased due to rising use of immunosuppressive therapies and the pandemic spread of HIV infection. More recently, the introduction of highly active antiretroviral therapy (HAART) in HIV has led to significant immune reconstitution, even in patients with previously long-lasting secondary immunodeficiency. HAART reduces morbidity and mortality in HIV infection and also changes the clinical course of prevalent subclinical opportunistic infections or autoimmune diseases. Atypical inflammatory disorders develop after initiation of HAART and have been summarized as "immune reconstitution syndrome," "immune restoration disease," and "immune restoration inflammatory syndrome." However, diagnostic criteria and standards of therapy are yet to be defined. The awareness for these diseases is of increasing importance from a clinical point of view. This review summarizes the variety of immunoreconstitution disorders and describes possible diagnostic pitfalls. We also propose possible therapeutic options.