Guillain-Barré Syndrome Associated with Zika Virus Infection in Colombia.

BACKGROUND: Zika virus (ZIKV) infection has been linked to the Guillain-Barré syndrome. From November 2015 through March 2016, clusters of cases of the Guillain-Barré syndrome were observed during the outbreak of ZIKV infection in Colombia. We characterized the clinical features of cases of Guillain-Barré syndrome in the context of this ZIKV infection outbreak and investigated their relationship with ZIKV infection. METHODS: A total of 68 patients with the Guillain-Barré syndrome at six Colombian hospitals were evaluated clinically, and virologic studies were completed for 42 of the patients. We performed reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assays for ZIKV in blood, cerebrospinal fluid, and urine, as well as antiflavivirus antibody assays. RESULTS: A total of 66 patients (97%) had symptoms compatible with ZIKV infection before the onset of the Guillain-Barré syndrome. The median period between the onset of symptoms of ZIKV infection and symptoms of the Guillain-Barré syndrome was 7 days (interquartile range, 3 to 10). Among the 68 patients with the Guillain-Barré syndrome, 50% were found to have bilateral facial paralysis on examination. Among 46 patients in whom nerve-conduction studies and electromyography were performed, the results in 36 patients (78%) were consistent with the acute inflammatory demyelinating polyneuropathy subtype of the Guillain-Barré syndrome. Among the 42 patients who had samples tested for ZIKV by RT-PCR, the results were positive in 17 patients (40%). Most of the positive RT-PCR results were in urine samples (in 16 of the 17 patients with positive RT-PCR results), although 3 samples of cerebrospinal fluid were also positive. In 18 of 42 patients (43%) with the Guillain-Barré syndrome who underwent laboratory testing, the presence of ZIKV infection was supported by clinical and immunologic findings. In 20 of these 42 patients (48%), the Guillain-Barré syndrome had a parainfectious onset. All patients tested were negative for dengue virus infection as assessed by RT-PCR. CONCLUSIONS: The evidence of ZIKV infection documented by RT-PCR among patients with the Guillain-Barré syndrome during the outbreak of ZIKV infection in Colombia lends support to the role of the infection in the development of the Guillain-Barré syndrome. (Funded by the Bart McLean Fund for Neuroimmunology Research and others.).

Aquaporin-4 serostatus does not predict response to immunotherapy in neuromyelitis optica spectrum disorders.

BACKGROUND: Debate exists about whether neuromyelitis optica spectrum disorder seronegative disease represents the same immune-mediated attack on astrocytic aquaporin-4 as in seropositive disease. OBJECTIVE: We investigated whether response to common treatments for neuromyelitis optica spectrum disorder differed by serostatus, as assessed by change in annualized relapse rate. METHODS: We performed a multicenter retrospective analysis of 245 patients with neuromyelitis optica spectrum disorder who were treated with either rituximab or mycophenolate mofetil as their first-line immunosuppressive treatment for disease prevention. Patients were followed for a minimum of 6 months following treatment initiation. RESULTS: In those started on rituximab, the pre-treatment annualized relapse rates for seropositive and seronegative patients were 1.81 and 1.93, respectively. On-treatment annualized relapse rates significantly declined to 0.32 (seropositive; p < 0.0001) and 0.12 (seronegative; p = 0.0001). In those started on mycophenolate mofetil, the pre-treatment annualized relapse rates for seropositive and seronegative patients were 1.79 and 1.45, respectively. On-treatment annualized relapse rates declined to 0.29 (seropositive; p < 0.0001) and 0.30 (seronegative; p < 0.005). CONCLUSION: In this international collaboration involving a large number of neuromyelitis optica spectrum disorder patients, treatment was effective regardless of serostatus. This suggests that treatment should not differ when considering these treatments.

Long-term outcomes of patients affected by Guillain-Barré syndrome in Colombia after the Zika virus epidemic.

BACKGROUND: Guillain-Barré Syndrome (GBS) can lead to significant functional impairments, yet little is understood about the recovery phase and long-term consequences for patients in low- and medium-income countries. OBJECTIVE: To evaluate the functional status and identify factors influencing outcomes among patients with GBS in Colombia. METHODS: Telephone interviews were conducted with GBS patients enrolled in the Neuroviruses Emerging in the Americas Study between 2016 and 2020. The investigation encompassed access to health services and functional status assessments, utilizing the modified Rankin Scale (mRS), GBS Disability Score (GDS), Barthel Index (BI), and International Classification of Functioning (ICF). Univariate analysis, principal component analysis, linear discriminant analysis, and linear regression were employed to explore factors influencing functional status. RESULTS: Forty-five patients (mean age = 50[±22] years) with a median time from diagnosis of 28 months (IQR = 9-34) were included. Notably, 22% and 16% of patients did not receive rehabilitation services during the acute episode and post-discharge, respectively. Most patients demonstrated independence in basic daily activities (median BI = 100, IQR = 77.5-100), improvement in disability as the median mRS at follow-up was lower than at onset (1 [IQR = 0-3] vs. 4.5 [IQR = 4-5], p < 0.001), and most were able to walk without assistance (median GDS = 2, IQR = 0-2). A shorter period from disease onset to interview was associated with worse mRS (p = 0.015) and ICF (p = 0.019). Negative outcomes on GDS and ICF were linked to low socioeconomic status, ICF to the severity of weakness at onset, and BI to an older age. CONCLUSIONS: This study underscores that the functional recovery of GBS patients in Colombia is influenced not only by the natural course of the disease but also by socioeconomic factors, emphasizing the crucial role of social determinants of health.