Kentaro Susaki

Association of Higher Methotrexate Dose With Lymphoproliferative Disease Onset in Rheumatoid Arthritis Patients

Methotrexate (MTX) is used as an anchor drug for rheumatoid arthritis (RA). Lymphoproliferative disease (LPD) occasionally develops in patients treated with MTX, and is known as MTX‐associated LPD (MTX‐LPD). Although MTX‐LPD occurs mainly in RA patients, it has not been established if MTX administration is an independent risk factor for LPD in RA patients. We examined the clinical characteristics of MTX‐LPD in Japanese RA patients and attempted to determine the risk factors for MTX‐LPD development.

Two cases of refractory thrombotic thrombocytopenic purpura associated with collagen vascular disease were significantly improved by rituximab treatment

Thrombotic thrombocytopenic purpura (TTP) is a rare disorder of small vessels. TTP is associated with deficiency of the von Willebrand factor-cleaving protease, ADAMTS13, and its inhibitor. Low ADAMTS13 activity is present in most of idiopathic TTP patients. The prognosis of TTP was improved by plasma exchange treatment, which replaces the ADAMTS13 and removes ADAMTS13 inhibitor. However, ADAMTS13 activity is normal in some TTP patients. These are found among the secondary TTP patients associated with collagen disease, hematopoietic stem cell transplantation, malignancy, or drugs. In addition, most of them do not respond to plasma exchange. On the other hand, several reports demonstrated that rituximab, which is an anti-CD20 monoclonal antibody, is effective for refractory TTP cases caused by ADAMTS13 deficiency. It is considered that the effect of rituximab is associated with disappearance of ADAMTS13 inhibitor. However, rituximab therapy was effective for the TTP patients with normal ADAMTS13 activity in our cases. We considered another mechanism of rituximab for TTP cases.

A case of Evans syndrome combined with systemic lupus erythematosus successfully treated with rituximab

Evans syndrome is a rare autoimmune disorder with unknown aetiology. Although corticosteroids and/or intravenous immunoglobulin (IVIG) are commonly used in its treatment, no standard strategy has been established. We report here a 44‐year‐old male with refractory Evans syndrome combined with systemic lupus erythematosus (SLE) who responded well to rituximab. He was admitted to our hospital with severe bleeding caused by worsening of Evans syndrome. Despite treatment with a high‐dose corticosteroid and IVIG, his thrombocytopaenia and haemolytic anaemia did not improve. We started rituximab at a dose of 375 mg/m2 once a week for a total of two doses. There was significant improvement in his thrombocytopaenia and anaemia 1 month after administration of rituximab. Although the total immunoglobulin G (IgG) level did not change, the titres of platelet‐associated IgG (PA‐IgG) and of an indirect antiglobulin test (IAT) decreased under the treatment with rituximab. It is suggested that rituximab would be a powerful candidate in the treatment of refractory Evans syndrome by depleting abnormal clone‐producing autoantibody.

A multicenter phase II prospective clinical trial of glucocorticoid for patients with untreated IgG4-related disease

Abstract Objective: Although glucocorticoids are effective for patients with IgG4-related disease, the treatment has not yet been standardized. Therefore, the treatment strategy should be established. Patients and methods: Patients who fulfilled the comprehensive diagnostic criteria for definite IgG4-related disease were started on prednisolone (0.6 mg/kg body weight) with the dose reduced every two weeks. The subsequent maintenance dose and need for prednisolone were determined for individual patients. The primary endpoint was the complete remission (CR) rate at one year. Secondary endpoints included overall response rate (ORR), the maintenance dose, the relapse rate, and adverse events. Results: This study enrolled 61 patients. After clinicopathological review, three patients were excluded, and one, 13, and 44 patients were diagnosed with probable, possible, and definite IgG4-related disease, respectively. Of the 44 patients with definite IgG4-RD, 29 (65.9%) achieved CR, and the ORR was 93.2%. No patient was refractory to primary treatment. The most frequent adverse events were glucose intolerance. Six patients relapsed. Conclusions: Glucocorticoid treatment is usually effective for patients with IgG4-RD, and we should examine the possibility of other disorders when a patient is glucocorticoid refractory. Some patients are misdiagnosed, making central clinicopathological review of diagnosis very important in conducting clinical studies.

Improvement of irregularity of brain vessel walls in systemic lupus erythematosus by tacrolimus.

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disease that affects multiple organs. Neuropsychiatric SLE develops during the course of the disease in 50% to 74% of SLE patients. The pathogenesis of CNS manifestations is multifactorial. The most common neuropathological finding has, in various studies, been multifocal infarcts. The cerebral vascular lesions in SLE that can cause cerebral infarction can be categorized into thromboembolism and vasculitis. On the other hand, tacrolimus is an immunosuppressive drug used for several autoimmune diseases, which inhibits the calcineurin pathway in T cells and reduces accompanying inflammatory cytokine production. We experienced that treatment of a patient with SLE with tacrolimus and steroid pulse therapy yielded improvement of vasculitis of brain vessels on magnetic resonance angiography. We suggest that tacrolimus may play an important role in the treatment of vasculitis of SLE.

Higher susceptibility of NOD/LtSz-scid Il2rg (-/-) NSG mice to xenotransplanted lung cancer cell lines.

Purpose No lung cancer xenograft model using non-obese diabetic (NOD)-scid Il2rg−/− mice has been reported. The purpose of this study is to select a suitable mouse strain as a xenogenic host for testing tumorigenicity of lung cancer. Materials and methods We directly compared the susceptibility of four immunodeficient mouse strains, c-nu, C.B-17 scid, NOD-scid, and NOD/LtSz-scid Il2rg−/− (NSG) mice, for tumor formation from xenotransplanted lung cancer cell lines. Various numbers (101–105 cells/head) of two lung cancer cell lines, A549 and EBC1, were subcutaneously inoculated and tumor sizes were measured every week up to 12 weeks. Results When 104 EBC1 cells were inoculated, no tumor formation was observed in BALB/c-nu or C.B-17 scid mice. Tumors developed in two of the five NOD-scid mice (40%) and in all the five NSG mice (100%). When 103 EBC1 cells were injected, no tumors developed in any strain other than NSG mice, while tumorigenesis was achieved in all the five NSG mice (100%, P=0.0079) within 9 weeks. NSG mice similarly showed higher susceptibility to xenotransplantation of A549 cells. Tumor formation was observed only in NSG mice after inoculation of 103 or fewer A549 cells (40% vs 0% in 15 NSG mice compared with others, respectively, P=0.0169). We confirmed that the engrafted tumors originated from inoculated human lung cancer cells by immunohistochemical staining with human cytokeratin and vimentin. Conclusion NSG mice may be the most suitable strain for testing tumorigenicity of lung cancer, especially if only a few cells are available.

A case of Degos disease successfully treated with corticosteroid combined with cyclophosphamide

Degos disease is a rare disorder characterized by systemic vasculitis involving various organs. There is no established, effective treatment for the disorder, and its prognosis is still poor. Combination therapy with corticosteroid and cyclophosphamide is considered effective for vasculitides involving the small arteries such as ANCA-associated vasculitis. We present here a 42-year-old man who developed Degos disease over several months, and was successfully treated using combined treatment with corticosteroid and cyclophosphamide.

Primary central nervous system lymphoma in a rheumatoid arthritis patient treated with methotrexate: a case report

BackgroundRheumatoid arthritis is a systemic inflammatory disease characterized by synovitis and the destruction of articular structures in multiple joints. Methotrexate is recommended as an anchor drug for rheumatoid arthritis treatment to achieve the therapeutic goal of reducing damage to joints and improving clinical score. However, several studies have shown that methotrexate has been associated with the development of lymphoproliferative disorders, namely methotrexate-associated lymphoproliferative disorders. On the other hand, primary central nervous system lymphoma is an aggressive disease with poor prognosis. Both methotrexate-associated lymphoproliferative disorders and primary central nervous system lymphoma are reported to be associated with Epstein-Barr virus.Case presentationA Japanese female patient of between 60 and 70 years of age with rheumatoid arthritis was admitted to our hospital because of sudden convulsion and impaired consciousness. Just before admission, she was treated with adalimumab and methotrexate. Contrast-enhanced computed tomography scan showed a densely stained mass with surrounding edema in both frontal lobes and the left nucleus basalis, and enlarged lymph nodes in the right supraclavicular fossa. We performed a biopsy of the right cervical lymph node, but could not establish a histopathological diagnosis. In situ hybridization showed the presence of Epstein Barr virus, therefore we diagnosed this case as methotrexate-associated lymphoproliferative disorders mediated by Epstein Barr virus after considering the drug history of the patient. After we discontinued methotrexate, patient symptoms gradually improved. The masses at both frontal lobes and the left nucleus basalis were gradually regressed.ConclusionSince the frequency of methotrexate use and the maximum dosage has been increasing, particular attention should be paid to the development of methotrexate-associated lymphoproliferative disorders in rheumatoid arthritis patients who are treated with methotrexate.

A case of catastrophic antiphospholipid syndrome, which presented an acute interstitial pneumonia-like image on chest CT scan

We report the case of catastrophic antiphospholipid syndrome (CAPS) complicated with mixed connective tissue disease (MCTD). A female patient was diagnosed with acute interstitial pneumonia (AIP) with MCTD by chest CT scan. Corticosteroid therapy was refractory for lung involvement, and she died due to acute respiratory failure. The autopsy revealed that AIP was compatible with lung involvement of CAPS. We therefore suggest that chest CT might reveal AIP-like findings in CAPS patients whose condition is complicated with pulmonary manifestations.

Tec protein tyrosine kinase inhibits CD25 expression in human T-lymphocyte.

The Tec protein tyrosine kinase (PTK) belongs to a group of structurally related nonreceptor PTKs that also includes Btk, Itk, Rlk, and Bmx. Previous studies have suggested that these kinases play important roles in hematopoiesis and in the lymphocyte signaling pathway. Despite evidence suggesting the involvement of Tec in the T-lymphocyte activation pathway via T-cell receptor (TCR) and CD28, Tecs role in T-lymphocytes remains unclear because of the lack of apparent defects in T-lymphocyte function in Tec-deficient mice. In this study, we investigated the role of Tec in human T-lymphocyte using the Jurkat T-lymphoid cell line stably transfected with a cDNA encoding Tec. We found that the expression of wild-type Tec inhibited the expression of CD25 induced by TCR cross-linking. Second, we observed that LFM-A13, a selective inhibitor of Tec family PTK, rescued the suppression of TCR-induced CD25 expression observed in wild-type Tec-expressing Jurkat cells. In addition, expression of kinase-deleted Tec did not alter the expression level of CD25 after TCR ligation. We conclude that Tec PTK mediates signals that negatively regulate CD25 expression induced by TCR cross-linking. This, in turn, implies that this PTK plays a role in the attenuation of IL-2 activity in human T-lymphocytes.