Immune reconstitution inflammatory syndrome following Cryptococcal neoformans infection in an immunocompetent host: A case report and review of the literature

Cryptococcal Meningitis in Young, Immunocompetent Patients: A Single-Center Retrospective Case Series and Review of the Literature

Background

Cryptococcal meningitis is an uncommon but serious infection with high mortality and morbidity. Classically described in immunocompromised patients, including those with solid organ transplants or HIV/AIDS, cryptococcosis has also been reported in young and otherwise healthy patients, albeit rarely.

Methods

We retrospectively searched for all cases of cryptococcal meningitis in young (≤50 years) and previously healthy patients with no known immunocompromising conditions from January 2015 to January 2022 at Indiana University Health (IU Health). Additionally, a PubMed literature review was performed with the keywords "cryptococcal meningitis" and "immunocompetent" from January 1988 to January 2022. Clinical courses, including outcomes and treatment regimens, were evaluated.

Results

We identified 4 local cases of cryptococcal meningitis in otherwise healthy patients age ≤50 years. Three cases were due to Cryptococcus neoformans, with 1 experiencing a postinfectious inflammatory response syndrome (PIIRS). The PubMed search identified 51 additional cases, with 32 (63%) being caused by Cryptococcus neoformans and 8 (17%) by Cryptococcus gattii. Of the 51 cases, only 2 resulted in death directly due to cryptococcosis. Fifteen (29%) had PIIRS, with steroid treatment documented in 11 of 15. Antifungal induction regimens and duration were varied but predominately consisted of amphotericin and flucytosine, with a mean induction duration of 5.0 weeks.

Conclusions

Cryptococcal meningitis in young, previously healthy patients is likely under-recognized. PIIRS (akin to immune reconstitution inflammatory syndrome observed in HIV/AIDS) with prolonged recovery should be of concern. Determining risk factors for cryptococcosis in these patients remains elusive.

Review: The application of corticosteroids in cryptococcal meningitis

Cryptococcal meningitis (CM) is a serious disease with high morbidity and mortality. Although the patients who received corticosteroids were at high risk of having CM, corticosteroids also have been used as an adjunct to antifungal drugs for treating people with CM in some situations (such as immune reconstitution inflammatory syndrome, cerebral cyptococcoma, et al.). Here, we summarize the current knowledge on the application of the corticosteroids in CM, aiming to help clinicians to reasonably use corticosteroids in patients with CM.

Post-Infectious Inflammatory Response Syndrome in an HIV-Negative Immunocompetent Elderly Patient With Cryptococcal Meningitis: A Case Report and Literature Review

We report a previously healthy 82-year-old male with cryptococcal meningitis (CM) who represented neurological deterioration due to post-infectious inflammatory response syndrome (PIIRS) occurring in 4 months after initial antifungal therapy. He was treated with corticosteroids for 2 months and recovered clinically. However, the clinical manifestation, cerebrospinal fluid (CSF), and brain magnetic resonance imaging (MRI) results got worse again on the next day after corticosteroid withdrawal. The analysis of inflammatory cytokines and culture on CSF, as well as brain MRI, still suggested a diagnosis of PIIRS. Therefore, corticosteroid therapy was used again and he subsequently obtained a complete resolution of symptoms.

Rapidly enlarging pulmonary mass due to immune reconstitution inflammatory syndrome (IRIS) in an immunocompetent host with pulmonary Cryptococcus neoformans

An immunocompetent man presented with Cryptococcus neoformans disease manifesting as a large pulmonary mass (cryptococcoma). Despite an initial induction course of 4 weeks of liposomal amphotericin B (LAmB), followed by 8 weeks of fluconazole, the cryptococcoma enlarged in size. Ten days into a second course of induction therapy with LAmB and flucytosine, the cryptococcoma markedly increased in size with encroachment on critical vascular structures. Due to concern for immune reconstitution inflammatory syndrome (IRIS), prednisone was added with significant decrease in the size of the mass. To our knowledge, this is the first reported case of pulmonary cryptococcal-IRIS in an immunocompetent host.