Bruno Seriolo

Anti-inflammatory mechanisms of methotrexate in rheumatoid arthritis

Methotrexate (MTX) is a folate analogue originally synthesised in the 1940s and designed to inhibit dihydrofolate reductase.1 Reduced folate (tetrahydrofolate) is the proximal single carbon donor in several reactions involved in the de novo synthetic pathways for purine and pyrimidine precursors of DNA and RNA required for cell proliferation. Furthermore, tetrahydrofolate plays a part in a second important biochemical step: the methionine-homocysteine cycle, which is necessary to provide a methyl group for several downstream reactions such as methylation of DNA, RNA proteins, and others. Therefore, MTX has been used extensively for treatment of neoplastic diseases. In 1951 the rationale for the introduction of MTX for the treatment of rheumatoid arthritis (RA) was that it inhibited proliferation of the lymphocytes and other cells responsible for inflammation in the joint.2 No further studies on clinical experience with MTX in RA were published until the early 1980s, when several uncontrolled trials were reported.3-8 Finally, four well designed, blinded, placebo controlled studies published in 1984 and 1985 introduced the use of MTX in the treatment of RA.9-12 The early indications for MTX use in the rheumatic diseases were first reported in a large review in 1984.13 From the considerable experience obtained over the past 15 years, several lines of evidence clearly suggest that MTX does not act simply as a cytotoxic (antiproliferative) agent for the cells responsible for the joint inflammation in RA.14 As a matter of fact, it would be difficult to understand how a drug that diminishes inflammation by preventing proliferation of immune cells might work at effective concentrations for only a very short time and once a week. In addition, the rapid clinical remission and the short term effect on the acute phase reactants, as seen with low dose MTX administration in most patients with …

Vitamin D in rheumatoid arthritis

The discovery of the vitamin D receptor (VDR) in the cells of the immune system and the fact that activated dendritic cells produce the vitamin D hormone suggested that vitamin D could have immunoregulatory properties. VDR, a member of the nuclear hormone receptor superfamily, was identified in mononuclear cells, dendritic cells, antigen-presenting cells, and activated T-B lymphocytes. In synthesis, the most evident effects of the D-hormone on the immune system seem to be in the downregulation of the Th1-driven autoimmunity. Low serum levels of vitamin D3 might be partially related, among other factors, to prolonged daily darkness (reduced activation of the pre vitamin D by the ultra violet B sunlight), different genetic background (i.e. vitamin D receptor polymorphism) and nutritional factors, and explain to the latitute-related prevalence of autoimmune diseases such as rheumatoid arthritis (RA), by considering the potential immunosuppressive roles of vitamin D. 25(OH)D3 plasma levels have been found inversely correlated at least with the RA disease activity showing a circannual rhythm (more severe in winter). Recently, greater intake of vitamin D was associated with a lower risk of RA, as well as a significant clinical improvement was strongly correlated with the immunomodulating potential in vitamin D-treated RA patients.

Androgens and estrogens modulate the immune and inflammatory responses in rheumatoid arthritis.

Abstract: Generally, androgens exert suppressive effects on both humoral and cellular immune responses and seem to represent natural anti‐inflammatory hormones; in contrast, estrogens exert immunoenhancing activities, at least on humoral immune response. Low levels of gonadal androgens (testosterone/dihydrotestosterone) and adrenal androgens (dehydroepiandrosterone and its sulfate), as well as lower androgen/estrogen ratios, have been detected in body fluids (that is, blood, synovial fluid, smears, salivary) of both male and female rheumatoid arthritis patients, supporting the possibility of a pathogenic role for the decreased levels of the immune‐suppressive androgens. Several physiological, pathological, and therapeutic conditions may change the sex hormone milieu and/or peripheral conversion, including the menstrual cycle, pregnancy, the postpartum period, menopause, chronic stress, and inflammatory cytokines, as well as use of corticosteroids, oral contraceptives, and steroid hormonal replacements, inducing altered androgen/estrogen ratios and related effects. Therefore, sex hormone balance is still a crucial factor in the regulation of immune and inflammatory responses, and the therapeutical modulation of this balance should represent part of advanced biological treatments for rheumatoid arthritis and other autoimmune rheumatic diseases.

Bone Metabolism Changes During Anti-TNF-α Therapy in Patients with Active Rheumatoid Arthritis

Abstract:  Osteoporosis (OP) occurs more frequently in patients with rheumatoid arthritis (RA) than in healthy individuals. Specific treatments of RA may increase susceptibility to OP, but at the same time decrease inflammatory activity, which is associated with accelerated bone loss. Treatment with TNF‐α blockers might influence bone metabolism and prevent structural bone damage in RA, in particular at the periarticular level. Our aim was to assess the influence of anti‐TNF‐α therapy on bone metabolism in RA patients. To that end we evaluated a group of 30 RA patients [mean age 50.6 ± 6.8 years; median disease duration 82 ± 38 months; median disease activity score (DAS‐28) 5.8 ± 1.2: 70% of whom were positive for the rheumatoid factor IgM (>40 IU/mL)]. Patients were treated with stable therapy of prednisone (7.5 mg/day) and methotrexate (MTX = 10 mg/week). Eleven of these RA patients further received etanercept (25 mg, twice/weekly) and 10 infliximab (3 mg/kg on 0, 2, 6, and every 8 weeks thereafter). A control group included 10 RA patients with stable therapy (prednisone and MTX) and without anti‐TNF‐α therapy. All the patients fulfilled the ACR criteria for the diagnosis of adult RA and were treated for 6 months. Quantitative ultrasound (QUS) bone densitometry was performed at the metaphyses of the proximal phalanges of both hands with a DBM Sonic 1200 QUS device (IGEA, Carpi, Italy). Amplitude‐dependent speed of sound (AD‐SoS) was evaluated at base line and at 3 and 6 months. Bone mineral density (BMD) of the hip and lumbar spine (L1–L4) was determined by a densitometer (GE Lunar Prodigy, USA) at base line at after 6 months. Soluble bone turnover markers [osteocalcin (BGP) and deoxypyridinoline/creatinine (Dpd/Cr) ratio] were measured in all patients at the same times, using enzyme‐linked immunosorbent assay tests. All data were compared using Wilcoxon signed rank test. Results were as follows: AD‐SoS values were found increased by 1.3% after 6 months of treatment in the RA patients treated with anti‐TNF‐α therapy. On the contrary, the Ad‐SoS levels decreased by 4.6% during the same period in the untreated RA group. BMD increased by 0.2% at lumbar spine and 0.1% at the hip in TNF‐α‐blocker‐treated patients and decreased by 0.8% and 0.6% (at lumbar spine and at the hip, respectively) in RA patients without anti‐TNF‐α therapy. However, BMD variations were not significant. In RA patients treated with TNF‐α blockers, BGP levels were found significantly increased (14.8 ± 3.8 mg/mL vs. 22.4 ± 4.2 mg/mL; P < 0.01) and Dpd/Cr levels were found significantly decreased (8.2 ± 2.1 nM vs. 4.6 ± 1.8 nM; P < 0.01) at 6 months when compared to base line values. On the contrary, there were no significant differences in the untreated RA patients concerning these latter parameters (BGP = 12.2 ± 3.1 mg/mL vs. 10.8 ± 2.8 mg/mL and Dpd/Cr = 8.9 ± 2.4 nM vs. 10.2 ± 1.8 nM, respectively). In conclusion, during 6 months of treatment of RA patients with TNF blockers, bone formation seems increased while bone resorption seems decreased. The reduced rate of OP appears to be supported by the same mechanisms involved in the decreased bone joint resorption during anti‐TNF‐α therapy, that is, the marked decrease of the proinflammatory (i.e., TNF‐α) cytokine effects on bone metabolism.

Effects of Anti‐TNF‐α Treatment on Lipid Profile in Patients with Active Rheumatoid Arthritis

Abstract:  Cardiovascular morbidity and mortality appear to be increased in rheumatoid arthritis (RA), which might be due to increased prevalence of risk factors for cardiovascular disease, such as an accelerated progression of atherosclerosis. Patients with active RA frequently show an atherogenic lipid profile, which has been linked with the inflammatory reaction. Tumor necrosis factor‐α (TNF‐α), a pivotal proinflammatory cytokine implicated in the pathogenesis of atherosclerosis in RA, may be involved in the development of the altered lipid profile observed in active RA. Our aim was to investigate the effects of anti‐TNF‐α treatment in combination with methotrexate (MTX) and corticosteroid therapy on lipid profile in patients with active RA. In this prospective study 34 consecutive RA patients were included (all women, mean age 51.6 ± 7.9 years, range 46–72 years) with active (defined as Disease Activity Index 28 joint score [DAS‐28], of at least 3.2) and refractory RA, in stable treatment with MTX (7.5–10 mg/week) and prednisone (7.5–10 mg/day) for 3 months. All patients received TNF‐α blockers (n= 16, etanercept 25 mg twice weekly; n= 14, infliximab 3 mg/kg on 0, 2, 6, and every 8 weeks thereafter; and finally, n= 4, adalimumab 40 mg every other week). Total cholesterol, high‐density lipoprotein cholesterol (HDL cholesterol), triglycerides (TG) and lipoprotein (a) [Lp(a)] levels and the atherogenic index (ratio cholesterol/HDL cholesterol) were measured at base line, and at 16 and 24 weeks. Results were as follows: The DAS‐28 was 6.9 ± 2.1 at base line and decreased to 4.6 ± 1.8 after 16 weeks, and further to 4.1 ± 1.3 after 24 weeks (both, P < 0.01). Following anti‐TNF‐α treatment, the mean levels of total cholesterol were 168 ± 24 mg/dL at base line and increased to 188 ± 28 mg/dL at 16 weeks (P < 0.01), and 197 ± 26 mg/dL at 24 weeks (P < 0.001). However, also the mean levels of HDL cholesterol were significantly higher than basal values after 16 and 24 weeks of treatment (34 ± 12 mg/dL versus 36 ± 18 mg/dL [P < 0.05] and 38 ± 14 mg/dL [P < 0.01], respectively). TG and Lp(a) levels, as well as the atherogenic index were not significantly changed. Interestingly, variations in disease activity were significantly and inversely correlated with HDL cholesterol levels. In conclusion: Short anti‐TNF‐α treatment was associated with a significant increase of both total cholesterol and HDL cholesterol levels, and correlated with decreased disease activity. The atherogenic index showed no changes during the study. Therefore, anti‐TNF‐α treatment might affect lipid profile in RA patients.

Circadian rhythms in RA

Possible roles of cortisol and melatonin It is well known that some clinical signs and symptoms of rheumatoid arthritis (RA) vary within a day and between days, and the morning stiffness seen in patients with RA has become one of the diagnostic criteria of the disease (fig 1).1 Figure 1 Clinical signs and symptoms of articular inflammation in patients with RA change consistently as a function of the hours of the day: pain and joint stiffness are greater after waking up in the morning than in the afternoon or evening. Among the clinical signs of joint inflammation in patients with RA, the intensity of pain changes consistently as a function of the hours of the day: pain is greater after waking up in the morning than in the afternoon or evening.2 In patients with RA circadian variations are also found in joint swelling and finger size and these symptoms are in phase with the circadian rhythm of pain. The RA rhythms differ in phase by about 12 hours from the circadian changes of left and right hand grip strength: a greater grip strength is seen when joint circumferences and the subjective ratings of stiffness and pain are least and vice versa.3 “Clinical signs and symptoms in RA depend on the time of day” Therefore, clinical signs and symptoms in RA show a rhythm that seems driven by a biological clock. Biological rhythms have been seen in different models of inflammation, and maximal inflammation occurred during the activity period of the animals—that is, between midnight and 8 00 am.4 Biological rhythms with a periodicity longer than 24 hours have also been detected, and a circaseptan rhythm (almost seven days) of paw oedema, over a period of 30 days, was observed, with peak of inflammation every 6–7 days.5 Furthermore, …

Melatonin serum levels in rheumatoid arthritis.

Abstract: The pineal hormone melatonin (MLT) exerts a variety of effects on the immune system. MLT activates immune cells and enhances inflammatory cytokine and nitric oxide production. Cytokines are strongly involved in the synovial immune and inflammatory response in rheumatoid arthritis (RA) and reach the peak of concentration in the early morning, when MLT serum level is higher. Nocturnal MLT serum levels were evaluated in 10 RA patients and in 6 healthy controls. Blood samples were obtained at 8 and 12 p.m., as well as at 2, 4, 6, and 8 a.m. MLT serum levels at 8 p.m. and 8 a.m. were found to be higher in RA patients than in controls (p < 0.05). In both RA patients and healthy subjects, MLT progressively increased from 8 p.m. to the first hours of the morning, when the peak level was reached (p < 0.02). However, MLT serum level reached the peak at least two hours before in RA patients than in controls (p < 0.05). Subsequently, in RA patients, MLT concentration showed a plateau level lasting two to three hours, an effect not observed in healthy controls. After 2 a.m., MLT levels decreased similarly in both RA patients and healthy subjects. Several clinical symptoms of RA, such as morning gelling, stiffness, and swelling, which are more evident in the early morning, might be related to the neuroimmunomodulatory effects exerted by MLT on synovitis and might be explained by the imbalance between cortisol serum levels (lower in RA patients) and MLT serum levels (higher in RA patients).

Use of glucocorticoids and risk of infections.

Glucocorticoids (GC) exert many complex quantitative and qualitative immunosuppressive effects that induce cellular immunodeficiency and consequently might increase host susceptibility to various viral, bacterial, fungal, and parasitic infections. In chronic immune/inflammatory conditions cortisol is secreted at inadequate levels and GC therapy today is devoted in substituting this hormone in adequate doses (low) to compensate just for this; therefore, the correct timing of GC administration, such as given during the turning-on phase of TNF secretion (night), can be of major importance. Consequently, the use of the lowest possible GC dose, at the night time and even for the shortest possible time, should decrease dramatically the risk of infections.

Sex hormones and rheumatoid arthritis.

Sex hormones are implicated in the immune response, with estrogens as enhancers at least of the humoral immunity and androgens and progesterone as natural immune-suppressors. In male rheumatoid arthritis (RA) patients, androgen replacement seems to ameliorate the disease and supports their involvement in the pathophysiology of the disease. The combination of androgens with cyclosporin A or methotrexate has been found to potentiate the apoptosis of monocytic inflammatory cells as well as to reduce the cell growth at least in vitro. Considerable interest has been devoted in the last years as to whether the use of oral contraceptive pills (OCs) may have a protective effect on the risk of RA. The results of many controlled studies have been found contradictory. At the present time, no consensus has been achieved regarding OCs administration and its relationship to the prevention or development of RA. In addition, an association of estrogen receptor gene polymorphism with age at onset of RA has been observed and might further explain inter-individual clinical and therapeutical-response variations. Local increased estrogen concentrations and decreased androgen levels have been observed in RA synovial fluids and seem to play a more important role in the immune/inflammatory local response.

Relations between steroid hormones and cytokines in rheumatoid arthritis and systemic lupus erythematosus

Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are multifactorial autoimmune diseases that originate from the patient’s excessive immune and inflammatory response to a pathogenic agent (that is, an infective antigen).1 The pathophysiological mechanisms are activated after the combination of several predisposing factors, which include the relations between histocompatibility epitopes and epitopes of the pathogenic antigen, the altered status of the stress response system (hypothalamic-pituitary-adrenocortical axis = HPA) and the gonadal hormone pattern (hypothalamic-pituitary-gonadal axis = HPG), with oestrogens principally implicated as enhancers of the immune response, and androgens and progesterone as natural suppressors (fig1).2-8 Figure 1 Genetic, infectious, and dietary factors, as well as gonadal/adreanal steroid hormones, play a predisposing part in autoimmune diseases such as RA and SLE. Therefore, the involvement of the hypothalamus-pituitary-adrenal (HPA = adrenal steroids) and -gonadal (HPG = gonadal steroids) axis is crucial and interferes with the immune system response. An intricate balance with bidirectional interactions between soluble mediators, released by the neuroendocrine system (that is, steroid hormones and neuropeptides) and products of activated cells of the immune/inflammatory system (cytokines) maintains the homeostasis in presence of the immune/inflammatory stimulus.9-12 Cytokine secretion seems fundamental in determining the duration and intensity of an immune response, and how steroid hormones (gonadal and adrenal steroids) influence autoimmunity may entail a further balance between Th1 and Th2 lymphocyte responses.13-15 Th1 lymphocytes produce mainly interleukin 2 (IL2) and interferon γ (IFNγ) and are primarly responsible for cell mediated immunity, while Th2 lymphocytes produce mainly IL4, IL5, IL13, and IL10, and are responsible for humoral immunity, supporting the activation of immunoglobulin secreting cells (fig 2).16 17 Figure 2 Role of Th1/Th2 cytokines in the regulation of cellular and humoral immunity. IL6, probably secreted by activated macrophages (Mφ) is able to polarise naive CD4+ T cells (Th0) to …