Sjögren’s syndrome with nervous system injury combined with pulmonary and osseous cryptococcosis: a case report

Background Sjögren’s syndrome is a common autoimmune disease that can involve the nervous system, but rarely both the central and peripheral. Long-term use of high-dose corticosteroids and immunosuppressants are the main risk factors for Cryptococcus infection in patients with Sjögren’s syndrome, of which pulmonary infection is the most common, while multiple bone infections are rare. Case presentation A 46-year-old Chinese woman with a 2-year history of Sjögren’s syndrome presented to our hospital with numbness of limbs, shortness of breath, and weakness. Blood immunochemistry showed that antinuclear antibody (1:640), anti-Sjögren’s syndrome-A antibodies, and anti-centromere antibodies were strongly positive. Cranial magnetic resonance imaging revealed multiple demyelinating lesions in the white matter of bilateral cerebral hemispheres. Electromyography indicated serious peripheral nerve injury, especially in lower limbs. Computed tomography scan of lumbar vertebral displayed multiple high-density shadows, and the corresponding vertebrae on magnetic resonance imaging showed abnormal low signal intensity on T1 and T2 sequences. Positron emission tomography–computed tomography showed multiple lesions with high 18F-fluorodeoxyglucose uptake in lung and vertebral bodies. Both lung and bone biopsies suggested Cryptococcus infection, with the diagnosis of Sjögren’s syndrome with nervous system injury combined pulmonary and osseous cryptococcosis. She took a reduced dose of prednisone about 10 mg/day, terminated mycophenolate mofetil, and began to take immunoglobulin of 0.4 g/kg/day intravenously for 5 days, fluconazole (400 mg/day) for 6 months. Within 3 weeks, her chest radiography showed a marked improvement, and 3 months later, the pulmonary lesions disappeared on her computed tomography scan. Conclusions This case exhibits an extremely rare condition of neural involvement in Sjögren’s syndrome combined with pulmonary and osseous cryptococcosis. This report also highlights the crucial role of detailed clinical examination, serologic markers, and biopsy in avoiding misdiagnosis. Currently, there is no guideline for this situation; in this case, we controlled the disease successfully with antifungal drugs and adequate gamma globulin, followed by an appropriate dose of corticosteroids.