[Rituximab: a original biotherapy in auto-immune disorders]

Anti-arthritic property of crude extracts of Piptadeniastrum africanum (Mimosaceae) in complete Freund's adjuvant-induced arthritis in rats

BACKGROUND

Rheumatoid arthritis, disease of unknown causes is a rheumatic and autoimmune pathology, recognised for its increasing frequency and its adverse consequences. It is a disease that occurs in most cases between 50 and 60 years and women are more affected than men. This study aimed at evaluating immunomodulatory and anti-arthritis capacity of aqueous and methanol extracts of stem bark of Piptadeniastrum africanum (Mimosaceae).

METHODS

ROS production from phagocytes, proliferation of T-cells, TNF-α and IL-1β production and cytotoxicity were performed by using chemiluminescence technique, liquid scintillation counter, ELISA and MTT assay, respectively. Anti-arthritic activity was evaluated using a model of adjuvant induced arthritis.

RESULTS

Methanol and aqueous extracts of Piptadeniastrum africanum significantly (P < 0.001) inhibited extracellular and intracellular ROS production. These extracts also possess significant (P < 0.001) inhibitory activity on T-cell proliferation other than reduced TNF-α and IL-1β production. Piptadeniastrum africanum also significantly exhibited antiarthritic activity in complete Freund's adjuvant induced arthritis in rat associated with a significant anti-inflammatory and anti-hyperalgesia activity.

CONCLUSIONS

Immunomodulatory, anti-inflammatory, antihyperalgesia and anti-arthritis potential revealed in this study approve that, Piptadeniastrum africanum is a plant rich in compounds with anti-arthritic properties.

[Favourable outcome after treatment with rituximab in a case of seronegative non-paraneoplastic Lambert-Eaton myasthenic syndrome]

INTRODUCTION

Lambert-Eaton myasthenic syndrome is a rare and autoimmune presynaptic disorder of the neuromuscular junction, due in 85% of cases to autoantibodies directed against voltage-gated calcium channels. It is a paraneoplastic disorder in 50 to 60% of cases. Diagnosis involves a proximal muscle weakness and areflexia, associated with a significant increment after post-exercise stimulation in electrophysiological study. Symptomatic treatment is based on 3,4-diaminopyridine. No etiological treatment has proven its efficacy in both paraneoplastic and non-paraneoplastic Lambert-Eaton myasthenic syndrome.

CASE REPORT

We report a 41-year-old man who presented with a seronegative non-paraneoplastic Lambert-Eaton myasthenic syndrome in whom conventional immunosuppressive treatments (corticosteroids, azathioprine) failed, and who eventually improved after treatment with rituximab.

CONCLUSION

Rituximab was an effective and well-tolerated treatment in this case of seronegative non-paraneoplastic Lambert-Eaton myasthenic syndrome. Its indication should be discussed when conventional immunosuppressive therapy fails in both seropositive and seronegative patients.

Successful second bone marrow transplantation in Omenn's syndrome after bone marrow aplasia: a case report

Omenn's syndrome is a rare inherited variant of SCID. It is inevitably fatal, unless treated by bone marrow or stem cell transplantation. However, treatment-related complications and graft rejection are major obstacles to the success of transplantation. In this report, we describe an eight-month-old baby with Omenn's syndrome and disseminated BCGosis, who underwent allogenic BMT from his HLA-matched sister using anti-GVHD prophylaxis but without a conditioning regimen. Ten days after BMT, he developed acute GVHD involving the skin only (grade 1) with a flare of local BCGosis. Engraftment of 55% was demonstrated by FISH as early as the 11th day post-BMT. On day +48 post-BMT, he developed GVHD that was complicated by refractory pancytopenia, resistant to three doses of rituximab. Patient was re-transplanted (from the same donor) after receiving fludarabine and ATG, with successful engraftment and complete recovery from pancytopenia.

Rituximab Efficacy during a Refractory Polyarteritis Nodosa Flare

Polyarteritis nodosa (PAN) is a systemic vasculitis whose severe forms are treated with glucocorticoids and cyclophosphamide. Refractory patients are exposed to many complications, notably accelerated atherosclerosis. We report a case report of 71-year-old man followed for polyarteritis nodosa refractory to glucocorticoids and cyclosphosphamide. Systemic vasculitis relapses are followed to accelerated atherosclerosis: severe ischemic lesions led to amputation of lower limbs. Remission of refractory PAN is obtained with rituximab. Disappearance of biological inflammatory is allowed to regression of ischemic lesions in upper limbs. In this situation, we recommend a systematic vascular work-up for patients suffered from refractory vasculitis. On the other hand, therapeutic trials are needed to determine the real efficacy and place of rituximab in the treatment of polyarteritis nodosa.

Rituximab for the treatment of post-bone marrow transplantation refractory hemolytic anemia in a child with Omenn's syndrome

Omenn's syndrome is a rare severe combined immunodeficiency that kills affected subjects before the end of the first year of life unless patients are treated with bone marrow transplantation (BMT). Unfortunately, post-BMT patients may develop autoimmune diseases, such as autoimmune hemolytic anemia (AIHA), which sometimes fails to respond to standard therapies. Rituximab is a chimeric, human, immunoglobulin G1/k monoclonal antibody specific for the CD20 antigen expressed on the surface of B lymphocytes. Rituximab is currently only labeled for treatment of B-cell lymphoproliferative disorders, such as B-cell non-Hodgkin's lymphoma and follicular lymphoma; however, it is also employed in the treatment of a variety of disorders mediated by auto-antibodies, such as AIHA and transplant-related autoimmune disorders. Herein, we describe the case of a 23-month-old male child with Omenn's syndrome, who had undergone BMT and was successfully treated with rituximab (375 mg/m(2) intravenously, weekly for three times) for refractory post-BMT hemolytic anemia. Our findings evidence that rituximab should be considered for treatment of post-BMT AIHA refractory to traditional therapy also in children with primary immunodeficiencies; furthermore, rituximab might represent a means to obtain remissions without the toxic effects associated with corticosteroid and immunosuppressive agents.