[CARD9 Mutation in a Patient with Candida albicans Meningoencephalitis; A Case Report]

Primary immunodeficiencies are disorders that cause clinical findings ranging from mild diseases to life-threatening diseases in a wide age range. Infections are the most common complications of primary immunodeficiencies. Caspase associated recruitment domain-9 (CARD9) is a protein that plays a role in fungal immune response. CARD9 deficiency is one of the primary immunodeficiency disorders that show autosomal recessive inheritance and can cause different clinical pictures. It has been associated with various fungal infections such as superficial or deep dermatophytosis, invasive pheohifomycosis, cutaneous mucormycosis, extrapulmonary aspergillosis, mucocutaneous or invasive candidiasis. The most common infections in CARD9 deficiency are caused by Candida spp. In this report, a case of Candida albicans meningoencephalitis due to CARD9 deficiency was presented. It was learned from the medical story that a 37 years old male patient had no known disease or drug use, but had recurrent oral candidiasis and cutaneous fungal infections since childhood, and received liposomal amphotericin B treatment with the diagnosis of C.albicans meningoencephalitis two months ago. It was learned that he was discharged with voriconazole treatment after clinical improvement, and he stopped the voriconazole treatment after discharge and did not go for follow-up. The patient, who reapplied 1.5 months after discharge with complaints of headache, vomiting and altered consciousness, did not have fever and neck stiffness, and Kerning and Bruzinski sign was negative. An external ventricular drainage (EVD) catheter was inserted after hydrocephalus was detected in the brain computerized tomography (CT). In the cerebrospinal fluid (CSF) examination, erythrocyte count was detected as 340/mm3, and no leukocytes were seen. CSF protein level was 28 mg/dl, CSF glucose level was 59 mg/dl (simultaneous blood glucose level was 104 mg/dl). There was no yeast or bacteria in CSF Gram staining and no acidfast bacteria in Ziehl-Neelsen staining. It was learned that there was no growth in the Mycobacterium tuberculosis culture made from CSF sample taken at the first admission of the patient. Serum human immunodeficiency virus antibody was negative. Upon learning of fluconazole-susceptible C.albicans growth in the control CSF culture of the patient, the EVD catheter was changed, and liposomal amphotericin B treatment was started. CSF culture was repeated. Fluconazole-susceptible C.albicans continued to grow in CSF cultures repeated in the follow-ups. No pathology in favor of abscess was detected in the brain magnetic resonance imaging. Fluconazole was added to the current liposomal amphotericin B treatment. Having a history of recurrent mucocutaneous fungal infection in the patient and his siblings, whose parents were third-degree relatives, suggested CARD9 deficiency. In the molecular test studied from blood samples, homozygous p.Q295X mutation due to CARD9 deficiency was detected in the patient and his sister. However, the patient died on the 62nd day of hospitalization due to delayed diagnosis, cerebral complications due to recurrent C.albicans meningoencephalitis, and insufficient treatment as a result of failure to receive the granulocyte colony stimulating factor (G-CSF) treatment. Persistent fungal infections that develop in CARD9 deficiency cause serious complications and mortality. Considering the frequency of CARD9 deficiency in the Turkish population and the lack of diagnostic testing in our country, it is thought that there may be many patients who cannot be diagnosed and who progress with mortality or morbidity. In conclusion, this case was presented to emphasize the consideration of CARD9 deficiency in case of persistent invasive fungal infection or recurrent invasive fungal infection after treatment despite effective antifungal treatment in children and adults who do not have known risk factors for invasive fungal infections.