Complicações neuroimunológicas secundárias à infecção por arbovírus (Zika, Dengue e Chikungunya)

Abstract

Mosquitoes of the genus Aedes, endemic throughout Brazil, are the transmitters of the Zika (ZIKV), Dengue (DENV) and Chikungunya (CHIKV) viruses. These viruses are the cause of viral infectious diseases that can present different clinical conditions, and in some cases have serious health consequences, including neurological complications with a high risk of permanent sequelae. In a portion of patients, it is believed that the virus can trigger immune reactions that would result in acute inflammatory diseases of both the central nervous system (CNS) and the peripheral nervous system (PNS). Among them, acute disseminated encephalomyelitis (ADEM), spectrum disorder of optic neuromyelitis (NMOSD), optic neuritis, transverse myelitis, Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP). However, the relationship between viral infection and the risk of developing these diseases is poorly understood. The present study aimed to investigate the neuroimmunological complications secondary to arbovirus infection (Zika, Dengue and Chikungunya) in the serum of infected patients. Ninety eight serum samples collected in the Northeast and Southeast of Brazil were analyzed by immunoenzymatic and indirect immunofluorescence techniques to verify the positivity of arboviruses. Autoantibodies against gangliosides, aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) were detected by immunoblotting and cell-based assay (CBA). Of the total samples tested, 77 were positive for DENV and ZIKV detection, and 52 were positive for CHIKV detection. Due to the time elapsed between the beginning of the clinical symptoms until the collection, the majority of the patients were already in a convalescent period of the infection demonstrating a negative IgM serological status. Anti-AQP4 autoantibodies were negative for all samples, and only two were positive for anti-MOG autoantibodies. IgG anti-ganglioside autoantibodies were negative for all samples, and IgM had a weak (borderline) reaction for 8 samples. The most reported viral symptom was fever (20.7%), and the neurological symptom was motor deficit (32.1%). GBS and its variants were the neuropathies most found in reactive polyflaviviruses. Already, CIDP, acute polyneuropathy and mononeuritis were the others neuropathies most found in reactive alphavirus patients. Together, these data contribute to clarify the fact that not only the GBS is associated with arbovirus infections, but also other neurological diseases. It is of fundamental importance to investigate the amplitude of other syndromes, such as myelopathy, CIDP, encephalitis, ADEM, NMOSD and optic neuritis, which may be associated with ZIKV, DENV and CHIKV infections.