The role of NK and NKT cells in the pathogenesis and improvement of multiple sclerosis following disease-modifying therapies.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system (CNS) that T cells become autoreactive by recognizing CNS antigens. Both innate and adaptive immune systems are involved in the pathogenesis of MS. In recent years, the impact of innate immune cells on MS pathogenesis has received more attention. CD56bright NK cells, as an immunoregulatory subset of NK cells, can increase the production of cytokines that modulate adaptive immune responses, whereas CD56dim NK cells are more active in cytolysis functions. These two main subsets of NK cells may have different effects on the onset or progression of MS. Invariant NKT (iNKT) cells are other immune cells involved in the control of autoimmune diseases; however, variant NKT (vNKT) cells, despite limited information, could play a role in MS remission via an immunoregulatory pathway. AIM: We aimed to evaluate the influence of MS therapeutic agents on NK and NKT cells and NK cell subtypes. MATERIALS AND METHODS: The possible mechanism of each MS therapeutic agent has been presented here, focusing on the effects of different disease-modifying therapies on the number of NK and NKT subtypes. RESULTS: Expansion of CD56bright NK cells, reduction in the CD56dim cells, and enhancement in NKT cells are the more important innate immune cells alterations following the disease-modifying therapies. CONCLUSION: Expansion of CD56bright NK cells or reduction in the CD56dim cells has been associated with a successful response to different treatments in MS. iNKT and vNKT cells could have beneficial effects on MS improving. It seems that they are enhanced due to some of MS drugs, leading to disease improvement. However, a reduction in the number of NKT cells could be due to the adverse effects of some of MS drugs on the bone marrow.

Brodifacoum toxicosis and abortion in an Arabian mare.

A 3-year-old pregnant Arabian mare was referred to the Veterinary Teaching Hospital of Shahid Chamran University of Ahvaz with a history of bleeding and rodenticide ingestion. The results of paraclinical examinations showed severe normocytic and normochromic anemia, decreased serum total protein, albumin, and fibrinogen concentrations, increased serum total bilirubin, urea, and creatinine concentrations, as well as increased serum aspartate aminotransferase and creatine kinase activity. Three days after treatment, all the clinical signs were resolved, however, fetus abortion occurred. In order to confirm the suspected cause of abortion and toxicosis, high-performance liquid chromatography was performed on serum sample of mare and liver tissue of the aborted fetus and toxicosis was confirmed. Poisoning with brodifacoum is considered as an important and lethal poisoning for both human being and animals. To our knowledge, this is the first report of spontaneous toxicosis and abortion with brodifacoum. Brodifacoum toxicosis can be effectively managed with early diagnosis, good paraclinical examinations and appropriate treatment.

Evaluation of Biological Indicators of Fatigue and Muscle Damage in Arabian Horses After Race.

The aim of this study was to assay changes in blood biochemical parameters that resulted from exercise-induced muscle fatigue in horses participating in the two races (1,250 and 1,400 meters). Six male Arabian horses (3 to 6 years old) were used in this study. Blood samples were collected at time intervals including 1 hour before the race, immediately after the race, 1 and 24 hours after the end of race. Catalase (CAT), superoxide dismutase, glutathione peroxidase (GPX) activities, the blood level of malondialdehyde, protein carbonyl, and total antioxidant capacity (TAC) were measured, as well as muscle damage biomarkers including aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK) activities, and myoglobin were measured. The results showed that CAT activity and plasma TAC in the horse increased immediately after the race and then gradually decreased. The highest GPX activity in red blood cells was recorded 1 hour before the start of the race. Superoxide dismutase showed an incremental pattern after the race. Immediately after the race, there was a significant increase in the plasma levels of AST, which continued until 1 hour after the race. The activity of LDH and CK reached its highest value 1 hour after the race. According to our findings, it can be concluded that the horses were tired and antioxidant enzymes altered under fatigue conditions. Muscle damage biomarkers have increased, but these increases were in their natural ranges and did not indicate muscle damage in horses.