The investigation of killer-cell immunoglobulin-like receptors (KIRs) and their HLA ligands in Iranian patients with myasthenia gravis.

BACKGROUND: Myasthenia gravis (MG) is a disabling disease with the underlying pathophysiology of auto-antibodies attacking the postsynaptic acetylcholine receptors of neuromuscular junctions causing muscle weakness. Natural killer (NK) cells are innate immune cells that play an important regulative role in immune responses. The human killer-cell immunoglobulin-like receptors (KIRs) family is one of the receptors on NK cells that can either activate or inhibit NK cells. This study aimed to assess the possible role of KIR and their human leukocyte antigen (HLA) ligand genes susceptibility to MG in Iranian patients. METHOD: One hundred and sixty-three patients with MG diagnosis based on the presence of clinical symptoms and laboratory tests and 400 healthy volunteers were studied. We used the polymerase chain reaction (PCR) technique for genotyping 15 KIRs and 5 HLA genes. RESULTS: The results demonstrated that there was no significant difference in the frequency of KIR genes and inhibitory KIR genotypes between controls and patients. In MG patients, HLA-C1Asn80 was significantly less frequent than in matched controls. The frequency of HLA genotype number 7 was significantly lower in MG cases, compared to the controls. Analysis of activating KIR genotypes showed that genotype number 10 was significantly less frequent in MG cases than in matched controls. CONCLUSION: Our results suggest that the presence HLA-C1Asn80 might play a protective role against the pathogenesis of MG. The significantly decreased prevalence of one activating KIR genotype and one of the HLA genotypes in MG cases suggest that these genotypes can reduce the risk of MG development. To specifically reveal the impact of KIR and HLA in MG, more studies are required.

Application of muscle ultrasound for the evaluation of patients with amyotrophic lateral sclerosis: An observational cross-sectional study.

INTRODUCTION: We evaluated the association between muscle ultrasound, number of motor units, and clinical parameters, and assessed their utility for distinguishing amyotrophic lateral scleorisis (ALS) patients from healthy individuals. METHODS: Three muscle pairs (abductor pollicis brevis, abductor digiti minimi, and tibialis anterior) of 18 ALS patients and 18 controls underwent muscle ultrasound (echointensity and thickness) and assessment of motor unit number index (MUNIX). The clinical and functional status of participants were also assessed. RESULTS: Mean age of the patients was 53.8 ± 12.1 years, and score on the ALS Functional Rating Scale-Revised was 38.9 ± 4.1. Echointensity of all tested muscles of ALS participants was significantly higher than that of controls, but there was no significant difference in muscle thickness. Muscle echointensity correlated significantly with clinical and electrophysiological parameters. CONCLUSION: Echointensity of muscles was highly associated with clinical scales and MUNIX, confirming its relevance as an ancillary diagnostic test in ALS patients.

Clinical outcomes of transverse myelitis with myelin oligodendrocyte glycoprotein antibody versus negative cases among adults in Isfahan, Iran: A comparative study.

Background: The aim of this study was to evaluate the status of anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in patients with transverse myelitis (TM) and compare the clinical and imaging characteristics of MOG immunoglobulin G (IgG)-positive with negative cases. Methods: This cohort study enrolled 71 patients diagnosed with new-onset of TM who were being followed at a referral university clinic in Isfahan, Iran, from November 2016 to January 2019. Magnetic resonance imaging (MRI) images and blood samples for anti-MOG, anti-aquaporin 4 (anti-AQP4) (using the cell-based technique), and vasculitis-related antibodies were collected from patients. Outcomes were assessed by the evolution of the Expanded Disability Status Scale (EDSS) score and brain and spinal cord imaging findings within three months. All patients underwent imaging and clinical assessment during a mean period of one year as a follow-up. We compared the characteristics of clinical and radiological outcomes in MOG-IgG-positive and negative cases. Results: Of the total population studied, there were 26.8% men and 73.2% women, with a mean age of 33 ± 10 years. 12 (16.9%) patients were seropositive for MOG antibody and 17 (89.5%) were positive for anti-AQP4 antibodies. There was no significant association between anti-MOG antibody seropositivity and age, gender distribution, the presence of other autoimmune diseases, and number and interval of relapses. However, the involvement site of the spine at first imaging was significantly different between seronegative and seropositive patients. Conclusion: In patients with MOG antibody disease (MOG-AD) TM, the MRI findings suggest a preferential involvement of the cervical-thoracic section in seropositive cases which may help differentiate from non-MOG demyelination TM.