A case of application of metagenomic next generation sequencing technology in a case of Cyanobacteria marneffei infection / 中华检验医学杂志

ABSTRACT

On September 15, 2020, a patient came in to Peking Union Medical College Hospital after suffering from chest pain, rash and lymphadenopathy for more than 2 years, and expericing general pain for 8 months. He also lost 15 kilograms of weight in the past half a year. For chest pain, cough, and expectoration symptons, cephalosporins and symptomatic treatments were empirically used and the symptoms were relieved. However, drug-induced rash occurred. After anti-allergic treatments, the rash was relieved but the swelling of cervical lymph nodes was not relieved. Diagnostic antituberculosis therapy was employed after biopsy result showed multifocal granulomatous inflammation. The therapy reduced the lymph nodes, but the condition repeated, and the whole body pain appeared. Further examinations showed that lung cancer in the right upper lobe was accompanied by obstructive pneumonia and whole body metastasis to multiple sites. The patient had no history of immunosuppression, and the γ interferon antibody was strongly positive, adult-onset immunodeficiency syndrome was considered. In order to confirm the diagnosis, bone and tissue biopsy were necessary, but the patient failed to cooperate. The histopathological examination results of the right cervical lymph node and the left iliac bone biopsy were weakly acid fast staining positive, Nocardia infection was suspected. The clinical symptoms improved after using sulfanilamide and imipenem empirical treatments against Nocardia. The content of cyanobacteria marneffei, which was detected by metagenomic next generation sequencing, was low. More laboratory pathogenic examinations were actively confirmed for this rare pathogen. The antifungal treatment (amphotericin B plus itraconazole) was used after successfully cultivating the cyanobacteria marneffei pathogen. After two months, the body nodules and masses disappeared and the skin wounds healed. It is of great significance to the diagnosis and treatment of patients to obtain qualified samples, maintain timely communication between the laboratory and the clinic, and construct reasonable interpretations of the results of metagenomic next generation sequencing technology.