Rituximab Treatment Modulates the Release of Hydrogen Peroxide and the Production of Proinflammatory Cytokines by Monocyte at the Onset of Type 1 Diabetes

BACKGROUND

Monocytes are the main blood innate mononuclear phagocyte and one of the most important effector cells expressing Fcγ receptor, which is critical for the interaction with Fc domain of antibodies.

OBJECTIVE

To evaluate the effect of Rituximab (RTX, a chimeric human anti-CD20 monoclonal antibody) on the functional activities of Monocytes (MOs) at the onset of human Type 1 Diabetes (T1D).

METHODS

MOs were isolated from peripheral blood mononuclear cells (PBMCs) obtained from volunteer patients with recent-onset T1D and healthy control donors.

RESULTS

The levels of the production of Interleukin 1β (IL-1β) and IL-6 were significantly increased in MOs from patients with T1D when compared to MOs from healthy controls (respectively, p < 0.01 and p < 0.05). Similarly, Interferon γ (IFN-γ), and intracellular free Calcium Ion (ifCa2+) levels were increased in T1D MOs than in control MOs, but the difference did not reach a significant level. Conversely, the production levels of IL-4 and catalase activity, as well as of both phagocytosis and killing capacities were decreased in MOs of T1D patients compared to MOs from healthy controls, but the difference was not significant for catalase activity and killing capacity (respectively, p < 0.01, p > 0.05, p < 0.01, and p > 0.05). Additionally, treatment with RTX significantly upregulated phagocytosis (p < 0.05), markedly downregulated the release of IL-1β (p < 0.01), ifCa2+, hydrogen peroxide (H2O2), and slightly downregulated the Nitric Oxide Synthase (NOS) activity, NOS activity-to-arginase activity ratio, the levels of Lactate Dehydrogenase (LDH)-based cytotoxicity, and the production of IL-6 and IFN-γ. Moreover, RTX treatment significantly upregulated the production of IL-4 (p < 0.05), IL-10 (p < 0.01) and the catalase activity (p < 0.05).

CONCLUSION

Our study has shown for the first time that RTX can reverse the abnormal functional activities of MOs as well as their production of proinflammatory cytokines at the onset of T1D. From a therapeutic point of view, RTX may potentially be suggested at the beginning of T1D to immunomodulate innate immunity and inflammatory conditions.

Clinical association of baseline levels of conjugated dienes in low-density lipoprotein and nitric oxide with aggressive B-cell non-Hodgkin lymphoma and their relationship with immunoglobulins and Th1-to-Th2 ratio

Objective

The aim of this study was to highlight the clinical association of baseline levels of conjugated dienes in low-density lipoprotein (LDL-BCD) and nitric oxide (NO) with immunoglobulins (Igs) and T helper (Th)1/Th2 ratio in patients with newly diagnosed B-cell non-Hodgkin lymphoma (NHL).

Patients and methods

Thirty-two newly diagnosed patients with aggressive B-cell NHL and 25 age-, sex-, and body-mass-index-matched healthy controls were randomly selected for a cross-sectional case–control study conducted at the Hematology Department of Tlemcen Medical Centre University (northwest of Algeria).

Results

Circulating levels of LDL-BCD and NO and those of IgA and IgM were significantly higher in patients than in controls. The levels of Th1/Th2 ratio and plasma total antioxidant capacity were significantly lower in patients compared with controls, while malondialdehyde and protein carbonyl levels were significantly higher in patients. B-cell NHL was significantly associated with high levels of LDL-BCD from 25th to 75th percentile (25th percentile: relative risk [RR] =2.26, 95% confidence interval [CI] 1.42–3.59, P=0.014; 50th percentile: RR =2.84, 95% CI 1.72–4.68, P<0.001; 75th percentile: RR =5.43, 95% CI 2.58–11.42, P<0.001). Similarly, the disease was significantly associated with high levels of NO production from 25th to 75th percentile (25th percentile: RR =2.07, 95% CI 1.25–3.44, P=0.024; 50th percentile: RR =2.78, 95% CI 1.63–4.72, P<0.001; 75th percentile: RR =4.68, 95% CI 2.21–9.91, P<0.001). Moreover, LDL-BCD levels were positively and significantly correlated with interferon (IFN)-γ, whereas NO levels were inversely and significantly correlated with IFN-γ and Th1/Th2 ratio.

Conclusion

LDL-BCD and NO production seem to be associated with aggressive B-cell NHL and alteration of Th1/Th2 ratio. Our results have to be examined using ex vivo mechanistic studies leading to further investigations of these parameters, with an interest in the link between Epstein–Barr virus infection and NO and immunoglobulins.