Rheumatoid arthritis

The use of patient-specific stem cells in different autoimmune diseases

Autoimmune diseases are developed when the immune system mistakenly attacks the body’s cells. These inflammatory disorders can be inherited or triggered by external forces, such as type 1 diabetes, which is caused by the immune system's destruction of pancreatic beta cells. So far, stem cells such as hESC and iPSC have been used to treat autoimmune disorders such as type 1 diabetes, rheumatoid arthritis (RA), multiple sclerosis (MS), and systemic lupus erythematosus (SLE), although these procedures have certain ethical concerns. On the other hand, bone marrow-derived mesenchymal stem cells (BM-MSC) are thought to be the best source of stem cells. Later, it was shown that mesenchymal stem cells produced from autologous adipose tissues have a great potential for producing huge volumes of stem cells. In-vitro and in-vivo investigations using autologous hematopoietic stem cells and autologous mesenchymal stem cells have been carried out on various rodent and human models, while clinical trials for inflammatory diseases such as multiple sclerosis and diabetes mellitus have yielded promising results. We attempted to summarise the usage of diverse stem cells in the therapy of various autoimmune disorders in this review. Shortly, we expect that the use of autologous stem cells will provide a new perspective on the treatment of autoimmune disorders.

Anti-arthritic activity of ethanolic extract of Tridax procumbens (Linn.) in Sprague Dawley rats

Objective:

To determine the anti-arthritic effect of whole plant ethanolic extract of Tridax procumbens (Asteraceae) in female Sprague Dawley (SD) rats using the Freund's Complete Adjuvant (FCA) model.

Materials and Methods:

The plant was collected from different regions of Madurai District, Tamil Nadu, and the phytoconstituents were identified through chemical tests. Ethanol (95%) was used to obtain the whole plant extraction through Soxhlet extractor. Female SD rats were used for anti-arthritic screening. Arthritis was induced using FCA, and the anti-arthritic effect of the ethanolic extract of T. procumbens was studied at doses of 250 and 500 mg/kg. The effects were compared with those of indomethacin (10 mg/kg). At the end of the study, the liver enzyme levels were determined and a radiological examination was carried out.

Result:

The preliminary phytochemical analysis of the ethanolic extract of T. procumbens indicated the presence of alkaloids, tannins, flavonoids and saponins. T. procumbens at 250 and 500 mg/kg significantly inhibited the FCA-induced arthritis in the rats. This was manifested by as a decrease in the paw volume. The arthritic control animals exhibited a significant decrease in body weight compared with control animals without arthritis. T. procumbens animals showed dose dependent reduction in decrees in body weight and arthritis. At the same time, T. procumbens significantly altered the biochemical and haematological changes induced by FCA (P < 0.05). The anti-arthritic effect of T. procumbens was comparable with that of indomethacin.

Conclusion:

The whole plant extract of T. procumbens showed significant anti-arthritic activity against FCA-induced arthritis in female SD rats.

Stem cells in autoimmune diseases: Implications for pathogenesis and future trends in therapy

In this review we report the recent progresses, available in the literature, concerning the biology and the potential therapeutic role of both mesenchymal stem cells (MSCs) and hematopoietic stem cells in autoimmune diseases. Mesenchymal stem cells (MSCs) are responsible for the normal turnover and maintenance of adult mesenchymal tissues and their pleiotropic nature allows them to sense and respond to an event in the local environment, be it injury or inflammation. Recently, MSCs have been shown to have immune-modulatory properties and immunosuppressive capacities, acting on different immune cells both in vitro and in vivo, in addition to an immunologically privileged phenotype. Moreover, several works suggest that MSCs are defective in autoimmune diseases. These aspects are now considered the most intriguing aspect of their biology, introducing the possibility that these cells might be used as effective therapy in autoimmune diseases. Autoimmune diseases represent a failure of normal immune regulatory processes as they are characterized by activation and expansion of immune cell subsets in response to non-pathogenic stimuli. As autoimmune diseases can be transferred, or alternatively, cured, by stem cell transplantation, a defect in the hemopoietic stem cell as a cause of autoimmune diseases may be postulated. The rationale for autologous hematopoietic stem cell transplantation (HSCT) in autoimmune diseases is the ablation of an aberrant or self-reactive immune system by chemotherapy and regeneration of a new and hopefully self-tolerant immune system from hematopoietic stem cells. In the past 15years, more than 1500 patients worldwide have received HSCT, mostly autologous, as treatment for a severe autoimmune disease and the majority were affected by multiple sclerosis, systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, juvenile idiopathic arthritis and idiopathic cytopenic purpura.

Autologous hematopoietic stem cell transplantation in autoimmune diseases

The term 'autoimmune diseases' encompasses a spectrum of diseases whose clinical manifestations and, possibly, biological features vary widely. The results of conventional treatment are considered unsatisfactory in aggressive forms, with subsets of patients having short life expectancies. Relying on wide experimental evidence and more feeble clinical data, some research groups have used autologous hematopoietic stem cell transplantation (HSCT) in the most disabling autoimmune diseases with the aim of resetting the patient's immune system. Immunoablative conditioning regimens are preferred over their myeloablative counterparts, and some form of in vivo and/or ex vivo T-cell depletion is generally adopted. Despite 15 years' experience, published controlled clinical trials are still lacking, with the evidence so far available coming from pilot studies and registry surveys. In multiple sclerosis, clinical improvement, or at least lasting disease stabilization, can be achieved in the majority of the patients; nevertheless, the worst results are observed in patients with progressive disease, where no benefit can be expected from conventional therapy. Concerning rheumatologic diseases, wide experience has been acquired in systemic sclerosis, with long-term improvements in cutaneous disease being frequently reported, although visceral involvement remains unchanged at best. Autografting has proved to be barely effective in rheumatoid arthritis and quite toxic in juvenile idiopathic arthritis, whereas it leads to clinical remission and the reversal of visceral impairment in the majority of patients with systemic lupus erythematosus. A promising indication is Crohn's disease, in which long-term endoscopic remission is frequently observed. Growing experience with autologous HCST in autoimmune diseases has progressively reduced concerns about transplant-related mortality and secondary myelodysplasia/leukemia. Therefore, a sustained complete remission seems to be within the reach of autografting in some autoimmune diseases; in others, the indications, risks and benefits of autografting need to be better defined. Consequently, the search for new drugs should also be encouraged.

The use of stem cells for the treatment of autoimmune diseases

Autoimmune diseases constitute a heterogeneous group of conditions commonly treated with anti-inflammatory, immunosuppressant and immunomodulating drugs, with satisfactory results in most cases. Nevertheless, some patients become resistant to conventional therapy. The use of high doses of drugs in such cases results in the need for bone marrow reconstitution, a situation which has stimulated research into the use of hematopoietic stem cells in autoimmune disease therapy. Stem cell transplantation in such diseases aims to destroy the self-reacting immune cells and produce a new functional immune system, as well as substitute cells for tissue damaged in the course of the disease. Significant results, such as the reestablishment of tolerance and a decrease in the recurrence of autoimmune disease, have been reported following stem cell transplantation in patients with autoimmune disease in Brazil and throughout the world. These results suggest that stem cell transplantation has the potential to become an important therapeutic approach to the treatment of various autoimmune diseases including rheumatoid arthritis, juvenile idiopathic arthritis, systemic lupus erythematosus, multiple sclerosis, systemic sclerosis, Crohn's disease, autoimmune blood cytopenias, and type I diabetes mellitus.

Enhanced expression of mRNA for nuclear factor kappaB1 (p50) in CD34+ cells of the bone marrow in rheumatoid arthritis

Bone marrow CD34+ cells from rheumatoid arthritis (RA) patients have abnormal capacities to respond to tumor necrosis factor (TNF)-α and to differentiate into fibroblast-like cells producing matrix metalloproteinase (MMP)-1. We explored the expression of mRNA for nuclear factor (NF)κB in RA bone marrow CD34+ cells to delineate the mechanism for their abnormal responses to TNF-α. CD34+ cells were purified from bone marrow samples obtained from 49 RA patients and 31 osteoarthritis (OA) patients during joint operations via aspiration from the iliac crest. The mRNAs for NFκB1 (p50), NFκB2 (p52) and RelA (p65) were examined by quantitative RT-PCR. The expression of NFκB1 mRNA in bone marrow CD34+ cells was significantly higher in RA than in OA, whereas there was no significant difference in the expression of mRNA for NFκB2 and RelA. The expression of NFκB1 mRNA was not correlated with serum C-reactive protein or with the treatment with methotrexate or oral steroid. Silencing of NFκB1 by small interfering RNA abrogated the capacity of RA bone marrow CD34+ cells to differentiate into fibroblast-like cells and to produce MMP-1 and vascular endothelial growth factor upon stimulation with stem cell factor, granulocyte-macrophage colony stimulating factor and TNF-α without influencing their viability and capacity to produce β2-microglobulin. These results indicate that the enhanced expression of NFκB1 mRNA in bone marrow CD34+ cells plays a pivotal role in their abnormal responses to TNF-α and, thus, in the pathogenesis of RA.

A phase I-II trial of autologous peripheral blood stem cell transplantation in the treatment of refractory autoimmune disease

OBJECTIVES

To carry out a phase I-II trial to elucidate the feasibility and efficacy of high dose cyclophosphamide (CY) supported by autologous peripheral blood stem cell transplantation (PBSCT) in the treatment of severe and refractory autoimmune disease (AD).

METHODS

Peripheral blood stem cells (PBSCs) were mobilised during haematological recovery after relatively high dose CY (2 g/m2) for 2 days, followed by administration of granulocyte colony stimulating factor. After collecting PBSCs--more than 2x10(6) CD34+ cells/kg--by apheresis, CD34+ cells were immunologically selected and cryopreserved. Eight patients were enrolled--five had systemic sclerosis (SSc) alone, one had SSc with systemic lupus erythematosus, one amyopathic dermatomyositis (ADM), and one Wegener's granulomatosis (WG). All of the patients were treated with high dose CY (50 mg/kg) for 4 days and autologous PBSCT.

RESULTS

Haematopoietic reconstitution was rapid and sustained. Toxicity due to the regimen included various infections such as pneumonia, sepsis, cystitis, herpes zoster, and acute heart failure. However, there was no treatment related mortality. Encouraging results were obtained after autologous PBSCT. Sclerosis of the skin was markedly improved in all of the patients with SSc. Interstitial pneumonia (IP), evaluated by PaO2, serum KL-6 levels, and pulmonary high resolution computed tomography, improved significantly. In a patient with ADM, severe and progressive IP also improved markedly. In a patient with WG, the size of the left orbital granuloma decreased substantially, resulting in reduction of the exophthalmos.

CONCLUSIONS

These observations suggest that high dose CY with autologous PBSCT is feasible and may be effective in the treatment of severe and refractory AD.