Tatsuki Tomikawa

Clinicopathological analyses in patients with other iatrogenic immunodeficiency-associated lymphoproliferative diseases and rheumatoid arthritis

Abstract Despite numerous attempts to uncover the mechanism of other iatrogenic immunodeficiency-associated lymphoproliferative diseases (OIIA-LPDs), this mechanism remains poorly understood, especially in rheumatoid arthritis (RA) patients. We analyzed the data on 23 patients with LPDs and RA. Patients were categorized into three groups according to whether they had methotrexate (MTX); MTX-regressive LPDs, MTX-persistent LPDs or other drugs-mediated LPDs. The LPDs seen in OIIA-LPDs-RA might have a unique behavior to think about several rare phenotypes. The overall survival of all patients was 74% at 5 years, and those of the three groups were 100%, 64% and 60%, respectively. Among the 6 patients who died, 4 had LPDs that were detected late, and thus adequate treatment was not given. In addition, several patients with diffuse large B cell lymphoma with a complex karyotype achieved complete remission (CR). Only one among the 17 patients who achieved CR relapsed. OIIA-LPDs-RA appeared to have a better prognosis than other more common types of lymphomas. Regarding RA treatment, various anti-RA drugs were given to the patients after developing LPDs, including MTX, but no recurrent patients were documented.

TM-233, a novel analog of 1′-acetoxychavicol acetate, induces cell death in myeloma cells by inhibiting both JAK/STAT and proteasome activities

Although the introduction of bortezomib and immunomodulatory drugs has led to improved outcomes in patients with multiple myeloma, the disease remains incurable. In an effort to identify more potent and well‐tolerated agents for myeloma, we have previously reported that 1′‐acetoxychavicol acetate (ACA), a natural condiment from South‐East Asia, induces apoptotic cell death of myeloma cells in vitro and in vivo through inhibition of NF‐κB‐related functions. Searching for more potent NF‐κB inhibitors, we developed several ACA analogs based on quantitative structure–activity relationship analysis. TM‐233, one of these ACA analogs, inhibited cellular proliferation and induced cell death in various myeloma cell lines with a lower IC50 than ACA. Treatment with TM‐233 inhibited constitutive activation of JAK2 and STAT3, and then downregulated the expression of anti‐apoptotic Mcl‐1 protein, but not Bcl‐2 and Bcl‐xL proteins. In addition, TM‐233 rapidly decreased the nuclear expression of NF‐κB and also decreased the accumulation of cytosolic NF‐κB. We also examined the effects of TM‐233 on bortezomib‐resistant myeloma cells that we recently established, KMS‐11/BTZ and OPM‐2/BTZ. TM‐233, but not bortezomib, inhibited cellular proliferation and induced cell death in KMS‐11/BTZ and OPM‐2/BTZ cells. Interestingly, the combination of TM‐233 and bortezomib significantly induced cell death in these bortezomib‐resistant myeloma cells through inhibition of NF‐κB activity. These results indicate that TM‐233 could overcome bortezomib resistance in myeloma cells mediated through different mechanisms, possibly inhibiting the JAK/STAT pathway. In conclusion, TM‐233 might be a more potent NF‐κB inhibitor than ACA, and could overcome bortezomib resistance in myeloma cells.

The aggressive clinical courses of Hodgkin lymphoma primarily diagnosed as methotrexate-induced non-specific lymphoproliferative disorder in patients with rheumatoid arthritis

Recently, attention has been focused on methotrexate-induced lymphoproliferative disease (MTX-LPD), and atypical phenotypes are occasionally documented. We encountered two patients with rheumatoid arthritis (RA) who were diagnosed with non-specific LPD (LPD-nos). Biopsy samples were not obtained during the initial examination when the LPD development was discovered, and the patients achieved a complete response after MTX cessation (case 1) or steroid pulse therapy (case 2). However, the tumors flared up 1.5 years later, and LPD-nos was determined following biopsies of the lymph node (LN, case 1) and liver (case 2). Prednisolone was subsequently administered instead of chemotherapy; however, multiple masses, including in the spine (case 1), and severe icterus with liver dysfunction (case 2) were exacerbated within a few months. Although the re-biopsy of LN proved the presence of HL and radiation followed by aggressive chemotherapy rescued the patient (case 1), the superficially accessible biopsy site was not found, and autopsy finally revealed HL (case 2). In both cases, the underlying pathogenesis along with the B symptoms and laboratory abnormalities suggested MTX-LPD, HL in particular. Therefore, even if the pathological diagnosis does not confirm the specific LPD subtype, the administration of aggressive chemotherapy should be considered if the LPD activity flares severely.

Successful early romiplostim use in a case of severe immune thrombocytopenia with critical carotid arterial injury

Thrombopoietin receptor (TPO-R) agonists have been shown to be effective in refractory chronic immune thrombocytopenia (ITP); however, their efficacy in patients under critical care is not known. We report the case of a female patient with a newly diagnosed ITP who experienced severe bleeding from an external wound. The patient was administered the standard treatments for ITP, which are high-dose intravenous immunoglobulin (IVIg) and corticosteroids. However, following failure of these treatments, we administered romiplostim on day 6 after the onset of ITP. On day 6 after the initiation of romiplostim, there was improvement in platelet count and bleeding tendency. We were subsequently able to perform a splenectomy successfully. The efficacy of TPO-R agonists in ITP has been reported in several situations, including before surgery in an ITP patient; however, the use of TPO-R for arterial bleeding with shock has not been reported. To our knowledge, the present article is a rare case report of the use of a TPO-R agonist in a patient with critical artery injury. Our data suggest that the early use of romiplostim is effective in emergency cases of newly diagnosed ITP with life-threatening bleeding, which is refractory to standard treatment.