Frequency of Dimethyl Fumarate Induced Lymphopaenia Among Omani Patients with Multiple Sclerosis

Objectives: Dimethyl fumarate (DMF) is known to cause lymphopenia in treated multiple sclerosis (MS) patients. There is a dearth of research on DMF therapy in the Arab world, especially in Oman. This study aimed to analyse the prevalence of lymphopenia among Omani MS patients and the reasons for discontinuing DMF. Methods: In this retrospective study, we reviewed the medical records of Omani MS patients who were treated using DMF at two tertiary hospitals in Muscat from the period 2017 February to 2023 February. Their demographic, clinical, and laboratory data were retrieved and analysed. Absolute lymphocyte count (ALC) values at baseline and at the last follow up, as well as the reasons for discontinuing DMF were collected. Descriptive and inferential statistical techniques were used for data analysis. Binary-logistic regression analysis was used to identify the risk factors for DMF-induced lymphopenia. Results: The study included a total of 64 MS patients and the majority (40; 63%) were female. The DMF therapy was started at mean age of 33 7.7 years. After administration of DMF, 14 (21.9%) patients developed 1–3 grades lymphopenia with the following breakup: grade-1: 5/64 (7.81%) patients; grade-2: 8/64 (12.5%) patients; grade-3: 1/64 (1.6%) patient. DMF was discontinued in 23 (36.0%) patients, mainly in response to adverse events or confirmed pregnancy. Female sex was the only significant predictor of DMF-induced lymphopenia (p = 0.037). Conclusion: Most Omani MS patients had mild lymphopenia (grades 1–2), like other regional and international reports. Early adverse events and pregnancy were the main reasons provided for discontinuing DMF therapy. Keywords: Multiple Sclerosis; Dimethyl Fumarate; Absolute Lymphocyte Count; Lymphopenia; Oma

Indicators and risk factors of infectious laryngotracheitis in layer hen flocks in Algeria

Background and Aim: Since 2017, there have been epidemics with respiratory disorders in the laying hen farms in Algeria, as signs and lesions, respiratory difficulties, and hemorrhagic tracheitis, which closely like laryngotracheitis. This study aimed to analyze the epidemiological, serological, and clinical indicators, as well as the risk factors, of infectious laryngotracheitis (ILT) in layer hen flocks in Algeria. Materials and Methods: A total of 1728 layer hens were sampled randomly from 48 poultry houses. Blood samples were collected from each hen at the wing vein area, and an indirect enzyme-linked immunosorbent assay was done using an IDvet® kit. Results: The flocks showed 56.25% seroprevalence. Clinical signs and gross lesions of ILT suspect cases included respiratory signs characterized by hemorrhagic tracheitis and sinusitis; conjunctivitis; egg drop; and a low mortality rate varying from 5% to 20%. Statistical analyses showed the effect of risk factors on the seropositivity for ILT in 48 layer flocks. When the vaccination was not applied, flocks were significantly more seropositive by 54% (odds ratio OR=1.54, p=0.01) compared to vaccinated flocks. Furthermore, flocks with poor hygiene were more seropositive by 68% (OR=1.68, p=0.002) compared to those with good hygiene. Finally, flocks with decreased egg production between 10% and 30% were significantly more seropositive by 42% (OR=1.42, p=0.04) than those with egg production >30%. Conclusion: The serological survey revealed anti-ILT virus antibodies, signifying the circulation of this virus in layer hen farms in Algeria. Correct vaccination protocol, strict biosecurity measures, rapid diagnosis, and detection of latent carriers are necessary to control and eradicate the disease from layer farms