Severe clinical immunodeficiency in a patient with human immunodeficiency virus infection and relatively high CD4 counts: a case report

Cryptococcus neoformans, a global threat to human health

BACKGROUND

Emerging fungal pathogens pose important threats to global public health. The World Health Organization has responded to the rising threat of traditionally neglected fungal infections by developing a Fungal Priority Pathogens List (FPPL). Taking the highest-ranked fungal pathogen in the FPPL, Cryptococcus neoformans, as a paradigm, we review progress made over the past two decades on its global burden, its clinical manifestation and management of cryptococcal infection, and its antifungal resistance. The purpose of this review is to drive research efforts to improve future diagnoses, therapies, and interventions associated with fungal infections.

METHODS

We first reviewed trends in the global burden of HIV-associated cryptococcal infection, mainly based on a series of systematic studies. We next conducted scoping reviews in accordance with the guidelines described in the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews using PubMed and ScienceDirect with the keyword Cryptococcus neoformans to identify case reports of cryptococcal infections published since 2000. We then reviewed recent updates on the diagnosis and antifungal treatment of cryptococcal infections. Finally, we summarized knowledge regarding the resistance and tolerance of C. neoformans to approved antifungal drugs.

RESULTS

There has been a general reduction in the estimated global burden of HIV-associated cryptococcal meningitis since 2009, probably due to improvements in highly active antiretroviral therapies. However, cryptococcal meningitis still accounts for 19% of AIDS-related deaths annually. The incidences of CM in Europe and North America and the Latin America region have increased by approximately two-fold since 2009, while other regions showed either reduced or stable numbers of cases. Unfortunately, diagnostic and treatment options for cryptococcal infections are limited, and emerging antifungal resistance exacerbates the public health burden.

CONCLUSION

The rising threat of C. neoformans is compounded by accumulating evidence for its ability to infect immunocompetent individuals and the emergence of antifungal-resistant variants. Emphasis should be placed on further understanding the mechanisms of pathogenicity and of antifungal resistance and tolerance. The development of novel management strategies through the identification of new drug targets and the discovery and optimization of new and existing diagnostics and therapeutics are key to reducing the health burden.

Neuromeningeal cryptococcosis in a patient not infected with human immunodeficiency virus and without known risk factors: A case report

We report a 24-year-old female patient not infected with human immunodeficiency virus (HIV) and without other risk factors of immunosuppression, presenting with neuromeningeal cryptococcosis. Cerebrospinal fluid (CSF) analysis revealed the presence of Cryptococcus neoformans. The evolution was unfavorable and the patient died even after appropriate antifungal treatment.

Unexpected case of cryptococcal meningoencephalitis in a patient with long-standing well-controlled HIV infection

Cryptococcal meningoencephalitis (CM) classically occurs in individuals with advanced HIV infection, solid organ transplants, or other immunocompromising conditions. We report a case of fatal CM in a 78-year-old woman with well-controlled HIV infection who had delayed diagnosis, persistently elevated intracranial pressure and pleocytosis of the cerebrospinal fluid. Initial suspicion for CM was low due to her relatively high CD4⁺ T cell counts, which likely contributed to greater inflammation.

Diagnostic and management considerations in the modern patient with AIDS: a case of concurrent disseminated Kaposi sarcoma and colesional Cryptococcus neoformans

In the era of highly active antiretroviral therapy (HAART), disseminated Kaposi sarcoma (KS) has become much rarer in the USA. We report a case of a 34-year-old man with KS of the skin, oropharynx, lung and rectum. Within the same lung nodule, we discovered significant burden of colesional Cryptococcus neoformans, in the context of a positive asymptomatic cryptococcal antigenemia, which was a previously unreported occurrence. The gold standard of treatment for KS continues to be HAART. The role of chemotherapy is still controversial. In addition, a cryptococcal antigen screen-and-treat approach with fluconazole is still not routinely recommended in the USA to prevent serious meningeal disease despite recent studies showing efficacy and applicability. We discuss both issues here and the outcome of our patient. We also present the patient's own unique perspective in dealing with the ramifications of these diagnoses.