Neutrophil-lymphocyte ratio in Guillain-Barré syndrome: A prognostic biomarker of severe disease and mechanical ventilation in Bangladesh.

In addition to cellular and humoral immunity, inflammatory markers play an important role in the pathogenesis of Guillain-Barré syndrome (GBS) and are used to predict prognosis in many autoimmune diseases. The aim of this study was to identify whether the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio, and monocyte-lymphocyte ratio in the early stages of GBS have prognostic value for severe disease, mechanical ventilation (MV) and poor long-term outcome. A prospective cohort study of 140 adult patients with GBS and 140 healthy controls (HC) was performed in Bangladesh during 2019-2022. Clinicodemographic characteristics of the patients were recorded, and hematological parameters were measured using an automated hematology analyzer. Median patient age was 35 (44-23) years; 71% were male; 88% were severely affected (GBS Disability Score> 3); 32% required MV. Patients had higher NLR than HC (P< .0001). Among patients, elevated NLR was associated with severe GBS and MV (P= .001 and <.0001, respectively) and moderately positively correlated with poor outcomes at 4 weeks (r = 0.423). Multiple logistic regression revealed NLR was an independent risk factor for severe GBS (OR = 5.2, 95% CI = 1.6-17.4) and MV (OR = 1.5 1.1-2.1). No significant association was observed between elevated NLR and the long-term outcome of GBS. Receiver operating characteristic curves revealed NLR cut-off values of ≥ 2.432 and ≥ 4.4423 predicted severe disease (sensitivity = 71%, specificity = 75%, AUC = 0.750, 95% CI = 0.651-0.849, P = .001) and MV (sensitivity = 65.9%, specificity = 81.7%, AUC = 0.804, 95% CI=0.724-0.884; P< .001). The NLR in the early stage of GBS may represent an independent prognostic factor of severe GBS and the requirement for MV.

High resolution melting curve analysis targeting the HBB gene mutational hot-spot offers a reliable screening approach for all common as well as most of the rare beta-globin gene mutations in Bangladesh.

BACKGROUND: Bangladesh lies in the global thalassemia belt, which has a defined mutational hot-spot in the beta-globin gene. The high carrier frequencies of beta-thalassemia trait and hemoglobin E-trait in Bangladesh necessitate a reliable DNA-based carrier screening approach that could supplement the use of hematological and electrophoretic indices to overcome the barriers of carrier screening. With this view in mind, the study aimed to establish a high resolution melting (HRM) curve-based rapid and reliable mutation screening method targeting the mutational hot-spot of South Asian and Southeast Asian countries that encompasses exon-1 (c.1 - c.92), intron-1 (c.92 + 1 - c.92 + 130) and a portion of exon-2 (c.93 - c.217) of the HBB gene which harbors more than 95% of mutant alleles responsible for beta-thalassemia in Bangladesh. RESULTS: Our HRM approach could successfully differentiate ten beta-globin gene mutations, namely c.79G > A, c.92 + 5G > C, c.126_129delCTTT, c.27_28insG, c.46delT, c.47G > A, c.92G > C, c.92 + 130G > C, c.126delC and c.135delC in heterozygous states from the wild type alleles, implying the significance of the approach for carrier screening as the first three of these mutations account for ~85% of total mutant alleles in Bangladesh. Moreover, different combinations of compound heterozygous mutations were found to generate melt curves that were distinct from the wild type alleles and from one another. Based on the findings, sixteen reference samples were run in parallel to 41 unknown specimens to perform direct genotyping of the beta-thalassemia specimens using HRM. The HRM-based genotyping of the unknown specimens showed 100% consistency with the sequencing result. CONCLUSIONS: Targeting the mutational hot-spot, the HRM approach could be successfully applied for screening of beta-thalassemia carriers in Bangladesh as well as in other countries of South Asia and Southeast Asia. The approach could be a useful supplement of hematological and electrophortic indices in order to avoid false positive and false negative results.