An Uncommon Infection in Common Variable Immunodeficiency

Cryptococcus neoformanscan cause life-threatening disease in both immunocompromised and healthy patients. We report a case of cryptococcal meningoencephalitis in a 68 year old patient with a history of common variable immunodeficiency due to a NFKB1 gene mutation and indeterminate colitis.

Our patient was admitted following a fall where he fractured his left humerus. During his admission, a persistent fever was noted despite broad spectrum antibiotic therapy. His neurological condition deteriorated over four weeks, with impaired cognition progressing to aphasia and obtundation. Following initial concerns over an ischaemic stroke, he was found to be serum cryptococcal antigen positive, and subsequent cerebrospinal fluid analysis confirmed CNS cryptococcosis by culture. His neurological condition improved with combination of liposomal amphotericin and flucytosine and he is currently undergoing rehabilitation.

The NFKB1 mutation is associated with common variable immunodeficiency and hypogammaglobulinaemia. Our patient was on weekly subcutaneous immunoglobulin replacement, but also required long term glucocorticoids (prednisolone 20mg daily) to control his colitis.

To our knowledge, this is the first description of cryptococcal meningoencephalitis in a patient with the NFKB1 mutation. Cryptococcal disease is an important differential diagnosis in immunosuppressed patients with fever and neurological symptoms and full recovery is possible with prompt recognition and treatment.