IL-12RB1 DEFICIENCY AND CRYPTOCOCCAL MENINGITIS: CASE REPORT

Abstract

The host immune response to C. neoformans infection is the result of a complex interplay between cellular and humoral immunity that often guarantees the control of infection in the immunocompetent host. Mendelian susceptibility to mycobacterial disease (MSMD) is associated to defects in the IL-12/23/IFN-gamma axis, leading to proneness to in tracellular/intravesicular pathogens such as Mycobacteria, Salmonella, Paracoccidioides and Histoplasma species. We are not aware of any Cryptococcal infection in MSMD patients. Herein we describe a case of the rare association between IL-12Rb1 deficiency and Cryptococcal meningitis. CMK, 29 years-old, female, referred to our service with symptoms of meningitis associated to signs of intracranial hypertension. The CSF exam showed a neutrophilic pattern and Cryptococcal cells were identified. NMR imaging showed several intraparenchymal lesions. The immunological evaluation showed normal lymphocytes count, negative serology to HIV, no proliferative response to PPD stimuli, despite previous BCG vaccination in childhood. Serum immunoglobulin concentrations were normal. The flow cytometric evaluation of the IL-12/23/IFN-gamma axis showed absent expression of IL-12RB1. We are now waiting for the molecular confirmatory test. The patient was treated with Amphotericin B and 5-fluorocytosine, without an adequate response. Fluconazole was added to the therapy without significant improvement. Unfortunately IFN-gamma is not approved by the Brazilian Ministry of Health, so we tried to get it by a judicial requirement. We then started IFN-gamma replacement with a quick improvement and complete neurological recovery. We believe that this is the first case of the association of CD212 deficiency and neurocryptococcosis.