Comparative effects on the immune system of methotrexate and trimetrexate

Clinical effectiveness of iguratimod based on real-world data of patients with rheumatoid arthritis

OBJECTIVES

Iguratimod (IGU) is a conventional synthetic disease-modifying drug that has been approved based on its additive effects with methotrexate (MTX) for the treatment of rheumatoid arthritis (RA). The objective of the study is to establish the effectiveness of IGU with versus IGU without MTX irrespective of whether MTX is well tolerated or not by the patients.

METHODS

Disease activity scores in 177 RA patients treated using IGU were retrospectively evaluated at baseline and after 4, 12, and 24 weeks, and adverse events (AEs) were noted.

RESULTS

IGU reduced the disease activity parameters, disease activity score (DAS)-ESR, DAS-CRP, the simplified disease activity index (SDAI), and clinical disease activity index (CDAI) in the concomitant MTX and non-MTX, female and male, and young and elderly patient groups after 24 weeks. Multivariate analysis demonstrated that IGU was more effective with concomitant MTX and in elderly and male patients. Severe AEs were observed only in the elderly group: two cases of pneumonia, 1 of pneumocystis pneumonia, 1 of heart failure, and 1 of salivary gland adenoma.

CONCLUSIONS

IGU is effective for RA, especially with concomitant MTX, and in elderly and male patients. Key Points • Iguratimod is effective for RA, especially with concomitant MTX, and in elderly and male patients. • Since all serious adverse events were in the elderly group in this study, sufficient monitoring for adverse events, especially for elderly RA patients, is needed during iguratimod therapy.

Investigation of the predictors of the response to Iguratimod therapy: A post-hoc analysis of post-marketing surveillance study

Objectives: The treatment response according to patient disease activity during Iguratimod therapy for rheumatoid arthritis has not been sufficiently assessed. A post-hoc analysis of post-marketing surveillance was performed. The treatment effect was evaluated using the European League against Rheumatism (EULAR) response criteria.Methods: Disease Activity Score (DAS) 28 was assessed at various time points. Patients showing a moderate or good response according to the EULAR response criteria at 24 weeks after the start of Iguratimod therapy were considered Responders. Propensity score matching was also performed, after which the factors with the greatest effect on the treatment evaluation were investigated.Results: The mean DAS28 at the start of administration and after 24 weeks was 4.31 and 2.52, respectively, in the Responder and 3.48 and 3.48, respectively, in the Non-responder. After propensity score matching for patient characteristics, the primary factors found to be related to being a Responder were concomitant use of methotrexate (MTX) with Iguratimod, and prior treatment with MTX before the start of Iguratimod.Conclusion: As factors related to the treatment effect, the concomitant use of MTX may contribute to achieving a better effect, and this study has shown that real-world are consistent with the results of clinical trials.

Effect of MX-68 on airway inflammation and hyperresponsiveness in mice and guinea-pigs

MX-68 is a newly synthesized antifolate, which is a derivative of methotrexate (MTX). In this paper, the effect of MX-68 on allergic airway responses in mice and guinea-pigs was studied. In the first experiment, antigen-induced airway inflammation and airway hyperresponsiveness (AHR) to acetylcholine in mice were examined and compared with the effects of classical antifolate methotrexate and prednisolone. Mice were sensitized with ovalbumin as an antigen and challenged with ovalbumin inhalation three times. After the last inhalation, AHR and airway inflammation were observed. An increase in Th2 cytokines (IL-4 and IL-5) and a decrease in a Th1 cytokine (IFN-gamma) in the bronchoalveolar lavage fluid (BALF), as well as an elevation of the immunoglobulin level in serum, were observed in sensitized mice. Oral administration of MX-68 had no effect on changes of body weight, but prednisolone reduced body weight during the experiment. The antigen-induced AHR and increases in the number of eosinophils and lymphocytes in BALF were significantly inhibited by MX-68. MX-68 interfered with the elevation of IL-4 and IL-5 levels in BALF, but had no effect on the decrease in IFN-gamma. Moreover, MX-68 significantly inhibited the elevation of serum IgE and IgG levels. In the guinea-pig model for bronchial asthma, biphasic increases in airway resistance (immediate asthmatic response, IAR, and late asthmatic response, LAR), as well as accumulated inflammatory cells in BALF, were observed after repeated antigen challenge. These asthmatic responses and inflammatory signs were significantly decreased by administration of MX-68. These results suggest that MX-68 obviously has an anti-inflammatory effect in an animal model of asthma and would be useful clinically for the treatment of bronchial asthma.

Effect of micronutrient status on natural killer cell immune function in healthy free-living subjects aged >/=90 y

BACKGROUND

Natural killer (NK) cells play a role in natural immunity against tumor and infected cells. Advanced aging is associated with functional impairment of NK cells and increased susceptibility to nutritional deficiencies.

OBJECTIVE

Our objective was to test whether micronutrient status affects NK cell activity in an older population.

DESIGN

The relations between NK cell variables (percentage of leukocytes and cytotoxicity) and blood concentrations of selected micronutrients were studied in 62 healthy, free-living northern Italian subjects (25 men, 37 women) aged 90-106 y. Anthropometric measurements were also made.

RESULTS

All subjects were well nourished according to age-specific anthropometric norms but many of them had micronutrient deficiencies. The prevalence of micronutrient deficiency was highest for selenium (in approximately 50% of both sexes), zinc (in 52% of men and 41% of women), and vitamin B-6 (in 40% of men and 59% of women), followed by vitamin A (in 16% of men and 27% of women) and vitamin E, vitamin B-12, and folate (each in <10% of both sexes). Ubiquinone-10 status was inadequate in 40% of women and 24% of men (P = 0.02). The percentage of NK cells was associated with serum zinc (men: r = 0.573, P = 0. 007; women: r = 0.373, P = 0.031) and selenium (women: r = 0.409, P = 0.018) concentrations. In women only, NK cell cytotoxicity at different effector-target cell ratios was positively associated with plasma vitamin E and ubiquinone-10 concentrations (P < 0.05). No significant associations with NK cell variables were found for the other measured nutrients.

CONCLUSIONS

The results of this study strengthen the hypothesis that individual micronutrients may affect the number and function of NK cells in old age. The study also confirms the high prevalence of micronutrient deficiencies in healthy and apparently well-nourished persons aged >/=90 y.

In vitro and in vivo biological activities of a novel nonpolyglutamable anti-folate, MX-68

MX-68 is a newly synthesized anti-folate, chemically designed not to undergo intracellular polyglutamation and to have increased affinity to dihydrofolate reductase (DHFR). In the present study, we examined the in vitro and in vivo biological activities of MX-68 compared with methotrexate (MTX) which forms several polyglutamates intracellularly. MX-68 dose-dependently inhibited the proliferation of PHA-, anti-CD3-, or PMA plus ionomycin-stimulated peripheral blood mononuclear cells (PBMC) and endothelial cells (EC) from normal subjects as well as IL-1 beta- or TNF alpha-stimulated synovial fibroblastic cells (SC) from rheumatoid arthritis (RA) patients. Coaddition of folinic acid completely reversed the anti-proliferative effects of both MX-68 and MTX. Although the anti-proliferative activities of MX-68 were almost comparable to those of MTX, the washout study clearly showed the characteristic nature of MX-68. When drugs were removed during culture, the suppressive effect of MX-68 completely disappeared, whereas suppression by MTX was merely weakened. MX-68 dramatically suppressed the onset of collagen-induced arthritis (CIA) in mice when the drug was orally administered three times a week. starting from the day of first immunization. In this model, 2 mg/kg of MX-68 was sufficient to completely suppress arthritis, whereas suppression by the same dose of MTX was partial. These lines of evidence suggest that polyglutamation is not always a prerequisite in the anti-rheumatic effects of anti-folate. In addition, since intracellular accumulation of polyglutamates is thought to have adverse effects, MX-68 may become a more potent and less toxic anti-rheumatic drug than MTX.

Double-blind, placebo-controlled multicenter trial using chimeric monoclonal anti-CD4 antibody, cM-T412, in rheumatoid arthritis patients receiving concomitant methotrexate

OBJECTIVE

To evaluate the clinical response to and safety of single and repeat doses of a chimeric anti-CD4 monoclonal antibody, cM-T412, in patients with rheumatoid arthritis (RA) concomitantly treated with a stable regimen of low-dose methotrexate.

METHODS

Sixty-four patients with refractory RA, who were already receiving stable doses of methotrexate, were randomized into a multicenter, double-blind, placebo-controlled trial to receive 3 monthly treatments with either a placebo, or 5, 10, or 50 mg cM-T412, given intravenously.

RESULTS

Using > or = 50% improvement in swollen joint counts as a criterion for clinical response, 13%, 13%, 18%, and 13% of patients receiving 50, 10, or 5 mg cM-T412, or the placebo, respectively, exhibited a clinical response at 3 months of therapy. Using > or = 50% improvement in tender joint counts as a measure of clinical efficacy at 3 months, 19%, 13%, 12%, and 6% of patients receiving 50, 10, or 5 mg cM-T412, or the placebo, respectively, exhibited a clinical response. "Flu-like" symptoms (fever, chills, rigor) within 24 hours of the infusion occurred more frequently in the groups receiving 50-mg (29%) and 10-mg (31%) doses of cM-T412 than those receiving 5 mg cM-T412 (12%) or the placebo (13%). Significant CD4+ T cell depletion occurred in the 50-mg group (mean of 353 CD4+ T cells/mm3 at 6 months versus 856 CD4+ T cells/mm3 at baseline). All patients were followed up for 12 months after the final treatment; no opportunistic infectious complications occurred.

CONCLUSION

Treatment with cM-T412 in this cohort of RA patients who were also taking methotrexate was not associated with clinical efficacy or enhanced toxicity from infectious complications, despite significant peripheral CD4+ T cell depletion.

Treatment of refractory rheumatoid arthritis with a chimeric anti-CD4 monoclonal antibody. Long-term followup of CD4+ T cell counts

OBJECTIVE

To evaluate CD4+ T cell counts of rheumatoid arthritis (RA) patients at 18 and 30 months after treatment with a chimeric anti-CD4 monoclonal antibody (MAb), cM-T412, in a phase I trial.

METHODS

Of the 25 RA patients who received the MAb, 23 were available for followup at 18 and 30 months. Levels of circulating CD4+ T cells were measured by flow cytometry.

RESULTS

Circulating CD4+ T cell levels in these 23 RA patients remained below normal at 18 and 30 months posttreatment. More profound CD4+ T cell depletion was noted in the higher-dose groups (300 and 700 mg).

CONCLUSION

Prolonged suppression of circulating CD4+ T cells was noted both in single-infusion and multiple-infusion groups 18 and 30 months after cM-T412 treatment. The depression was more pronounced in patients who received multiple infusions of cM-T412. The prolonged decrease in CD4+ T cell numbers suggests that the capacity to reconstitute CD4+ T cells in this patient population (treated with methotrexate) is limited. One patient, who was also receiving methotrexate and prednisone, died 18 months after receiving 100 mg of cM-T412. No other significant adverse effects, in particular, no opportunistic infections, were reported in these 23 RA patients at 18 and 30 months of followup.

Pentamidine blocks the pathophysiologic effects of endotoxemia through inhibition of cytokine release

Pentamidine isethionate, an antiprotozoal agent with therapeutic value against Pneumocystis carinii pneumonia, has been used for over 30 years without a precise understanding of its mechanism of pharmacologic action. We have previously reported that pentamidine has the capacity to inhibit the release of cytokines from macrophages through a post-translational processing event. The present studies were undertaken to assess the ability of pentamidine to modulate the detrimental effects of murine endotoxemia, a disease with a pathophysiology clearly linked to host-produced cytokines. Under conditions where normal B6C3F1 mice succumbed to the lethal effects of endotoxin, mice pretreated with pentamidine were significantly protected from both mortality and loss of thermoregulatory control. The EC50 for protection from mortality by pentamidine was approximately 11.4 mg/kg. These observations correlated with decreased serum levels of tumor necrosis factor (TNF) and interleukin 6. Inhibition of cytokines was not manifested as part of a generalized inhibition of protein synthesis as demonstrated by the lack of significant modulation of serum albumin in pentamidine-treated animals. In addition to decreased serum concentrations of cytokines, lungs isolated from mice treated with both pentamidine and endotoxin exhibited a decreased release of TNF compared to lungs isolated from mice treated with vehicle and endotoxin. The lower levels of TNF released from lung tissue in pentamidine-treated mice correlated with a lesser degree of alveolar deterioration than was observed in vehicle-treated mice. These data indicate that following endotoxin administration, pentamidine has a protective and antiinflammatory role both systemically and in the lung and suggest that inhibition of inflammatory cytokines may be one mechanism operable in the therapeutic activity of the drug against P carinii pneumonia.

Panax ginseng as a potential immunomodulator: studies in mice

There has been continuing interest in the development of synthetic and natural compounds which modify the immune response, particularly for the treatment of AIDS and cancer. Panax ginseng, employed for its putative medicinal properties in South Asia, was examined for its immunomodulatory properties in mice. A systematic evaluation of multiple immune system components revealed that Panax ginseng stimulated basal natural killer (NK) cell activity following subchronic exposure and helped stimulate recovery of NK function in cyclophosphamide-immunosuppressed mice but did not further stimulate NK activity in poly I:C treated mice. Other immunological parameters examined, including T and B cell responses were not affected. Panax ginseng provided a degree of protection against infection with L. monocytes but did not inhibit the growth of transplanted syngeneic tumor cells. Increased resistance to L. monocytogenes was not detected in challenged mice previously given immunosuppressive doses of cyclophosphamide. Taken together, these data suggest that Panax ginseng has some immunomodulatory properties, primarily associated with NK cell activity.

Paradoxical enhancement of interleukin-2-mediated cytotoxicity against K562 cells by addition of a low dose of methotrexate

In vitro effects of methotrexate (MTX) on interleukin-2(IL-2)-mediated cytotoxicity of peripheral blood mononuclear cells (PBMC) were studied. PBMC were incubated with human recombinant IL-2 (25 U/ml) for 72 h; during the last 24 h, various concentrations (10 pM-1 microM) of MTX were added to the culture. Cytotoxicity against k562 cells was measured by a 4-h 51Cr-release assay. The IL-2-mediated cytotoxicity was paradoxically increased at around a concentration (10 nM) MTX. Such a low concentration of MTX showed no anti-proliferative effect on cell growth. This enhancement with 10 nM MTX was shown only in an E-rosette+ (E+) population, but not in E-rosette- (E-). In addition, when E+ cells were treated with an anti-CD16 monoclonal antibody plus complement after incubation with IL-2 and MTX, MTX-induced enhancement was lost, suggesting that an E+CD16+ cell population was mainly involved in this augmentation. Positively sorted E+CD16+ cells showed similar enhancement of cytotoxicity after treatment with IL-2 plus MTX. On the other hand, MTX treatment did not show the phenotypical changes including of the E+CD16+ cells, indicating that this treatment did not affect the differentiation and proliferation of the specific cell subset. Our results indicate that a low dose of MTX could have a role in the regulation of immunological anti-cancer surveillance systems through the natural killer and lymphokine-activated cytotoxic cells.