Short and long-term immune changes in different severity groups of COVID-19 disease.

BACKGROUND: There are limited data on short- versus long-term changes in adaptive immune response across different COVID-19 disease severity groups. METHODS: A multicenter prospective study of 140 adult patients with COVID-19 (a total of 325 samples) were analyzed for inflammatory markers and lymphocyte subsets at presentation, week 2, and week 24. RESULTS: Inflammatory markers at presentation were higher in the critical/severe than in moderate and mild groups. A predominance of memory B cell response in the mild and moderate group was noted by week 2. In contrast, the immune system in the severe/critical group was dysfunctional, with expansion of exhausted CD8+ T cells and atypical memory B cells. By 24 weeks, there was a possible trend of normalization. CONCLUSION: There was substantial difference in the degree of inflammation and distribution of different B and T cell subsets in the different disease severity groups. Despite the initial dysfunctional immune response in the severe/critical group, a comparable memory B and CD8+ T cell responses to the mild group was achieved at 24 weeks.

Prevalence of Coeliac Disease in Omani Adults with Iron Deficiency Anaemia of Unknown Cause: Case-finding study.

Objectives: This study aimed to estimate the serological prevalence of coeliac disease in patients with iron deficiency anaemia (IDA) of unknown cause at a primary healthcare facility in Oman. Methods: This prospective case-finding study was conducted at the primary care clinics in Sultan Qaboos University Hospital, Muscat, Oman from September 2018 to June 2020. Patients aged 18 to 55 years, with a haemoglobin (Hb) level <11.5 g/dL for males and <11.0 g/dL for females and a ferritin level <30 ng/mL for males and <13 ng/mL for females, were included in the study. Blood samples were obtained for initial serological screening using serum immunoglobulin (Ig)A level; those samples with normal levels of IgA, IgA anti-tissue transglutaminase antibody (tTG) and IgA anti-deamidated gliadin peptide (DGP) were determined. Positive IgA-tTG test was confirmed using IgA-endomysial antibodies. Patients with low IgA levels were tested using IgG-tTG and IgG-DGP. Results: A total of 104 patients participated in this study. Eight patients (7.7%) were found to have a positive serological screening result for coeliac disease; of these patients, three (37.5%) had a positive IgA-tTG result. Two of those three (66.7%) had a positive IgA-endomysial antibody. The IgA-DGP result was positive in seven (6.7%) of the 104 patients. Out of those seven patients, two also had a positive IgA tTG. Conclusion: Coeliac disease is not a rare disorder. There is a need to increase awareness among healthcare professionals about coeliac disease and its non-classical manifestations such as IDA.

Overlapping demyelinating syndrome (Neuromyelitis optica spectrum disorders NMOSD with anti-NMDA receptor encephalitis); A case report.

Neuromyelitis optica spectrum disorder (NMOSD) represents an evolving spectrum of inflammatory demyelinating central nervous system-based autoimmune diseases; while anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is another severe immune-mediated syndrome that occurs in association with IgG antibodies against the GluN1 subunit of the NMDAR and has been predominantly reported in young females (Dalmau et al., 2008 Dec). Although It has been recognized that anti-NMDAR encephalitis can coexist in the same patient who has serological markers of another autoimmune disease (e.g. neuronal autoantibodies and demyelination AQP4 or MOG antibodies) (Titulaer et al., 2014), rare cases are reported with anti-NMDAR encephalitis that overlap with a demyelinating syndrome; such as neuromyelitis optica spectrum disorders associated with Anti- Aquaporin 4 (AQP4) antibodies (Titulaer et al., 2013). We report here an unusual and rare overlapping autoimmune syndrome in a young Omani female who first presented in 2011 with the clinical and radiological presentations of neuromyelitis optica spectrum disorder (NMOSD) and had a complete recovery. Five years later, she was admitted with the diagnosis of anti-NMDAR encephalitis and was found to have positive serum as well as CSF analyses results for AQP4 and anti-NMDAR antibodies. The patient showed significant improvement, for both clinical syndromes with good response to steroid and immunomodulating therapy.