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Elotuzumab-based regimens are sometimes selected for multiple myeloma treatment after daratumumab-based regimens. However, there has been insufficient discussion on the efficacy of elotuzumab after daratumumab. We used Kansai Myeloma Forum registration data in a multicenter retrospective evaluation of the efficacy of elotuzumab after daratumumab. Overall survival (OS) rate and time to next treatment (TTNT) were significantly worse in the cohort given elotuzumab after daratumumab (Dara cohort, n = 47) than in the cohort with no history of daratumumab administration before elotuzumab (No-Dara cohort, n = 80, OS: P = 0.03; TTNT: P = 0.02; best response: P < 0.01). In the Dara cohort, OS and TTNT rates were worse with sequential elotuzumab use after daratumumab than with non-sequential (OS: P = 0.02; TTNT: P = 0.03). In patients given elotuzumab < 180 days after daratumumab, OS (P = 0.08) and best response (P = 0.21) tended to be worse, and TTNT was significantly worse (P = 0.01), than in those given elotuzumab after ≥ 180 days. These findings were confirmed by subgroup analyses and multivariate analyses. Monoclonal-antibody-free treatment might be preferable after daratumumab-based regimens. If possible, elotuzumab-based regimens should be considered only ≥ 180 days after daratumumab use. [ABSTRACT FROM AUTHOR]

Knowledge of the SARS-CoV-2 antibody titers induced by tixagevimab–cilgavimab in patients with hematologic diseases remains insufficient. Here, we performed a single-center, prospective study to reveal the changes in antibody titer after administration of tixagevimab–cilgavimab in 78 patients with hematologic diseases. The median peak titer was 155.4 U/mL, and the median AUC was 46556 days·U/mL. First, we compared several characteristics between patients with low titers (peak titer ≤ 155.4 U/mL) and high titers (peak titer > 155.4 U/mL). We extracted 6 factors (patient age, sex, ECOG-PS, serum albumin level, and cross-sectional area and computed tomographic number of the psoas major muscle) as candidates influencing the antibody titers. Multiple regression analysis revealed that antibody titer was closely associated with these 6 factors (contribution rate = 0.76, p = 0.02). Our data support the inability of tixagevimab–cilgavimab to induce sufficient antibody titers against SARS-CoV-2, especially in older, frailer, female patients. [ABSTRACT FROM AUTHOR]

Allogenic hematopoietic stem cell transplantation (allo-HSCT) is not a standard therapy for solid cancer because of its high toxicity and insufficient evidence levels. However, the potential graft-versus-solid-tumor (GVT) effect of this therapy has been discussed. Many case reports have also described treatment effects of allo-HSCT in patients with hematologic malignancies and active solid tumors. A 38-year-old woman treated with fulvestrant and abemaciclib for recurrent breast cancer with multiple lung metastases was diagnosed with myelodysplastic syndrome (MDS) with increased blasts 2. She was classified as adverse risk by the 2017 European LeukemiaNet risk stratification and as very high risk by the Molecular International Prognostic Scoring System. Breast cancer treatment was interrupted and venetoclax and azacitidine therapy was started. Complete hematologic response was achieved after three cycles. However, multiple lung metastases from the breast cancer remained. The patient then underwent umbilical cord blood transplantation. She has maintained complete remission of MDS as of 1 year post-transplantation, without serious complications. Lung metastatic activity on FDG-PET/CT scan also completely disappeared by half a year post-transplantation, and this response has continued as of 1 year post-transplantation. This favorable treatment course suggests the existence of a GVT effect. [ABSTRACT FROM AUTHOR]

Summary: Morphological dysplasia in haematopoietic cells, defined by a 10% threshold in each lineage, is one of the diagnostic criteria for myelodysplastic neoplasms. Dysplasia limited to the erythroid lineage has also been reported in some cases of aplastic anaemia (AA); however, its significance remains unclear. We herein examined the impact of erythroid dysplasia on immunosuppressive therapy responses and survival in AA patients. The present study included 100 eligible AA patients without ring sideroblasts. Among them, 32 had dysplasia in the erythroid lineage (AA with minimal dysplasia [mini‐D]). No significant sex or age differences were observed between AA groups with and without erythroid dysplasia. In severe/very severe AA and non‐severe AA patients, a response to anti‐thymocyte globulin + ciclosporin within 12 months was observed in 80.0% and 60.0% of AA with mini‐D and 42.9% and 90.0% of those without dysplasia, with no significant difference (p = 0.29 and p = 0.24 respectively). Overall survival and leukaemia‐free survival did not significantly differ between the groups. Collectively, the present results indicate that the presence of erythroid dysplasia did not significantly affect clinical characteristics or outcomes in AA patients, suggesting that its presence in AA is acceptable. Therefore, erythroid dysplasia should not exclude an AA diagnosis. [ABSTRACT FROM AUTHOR]

Although exposure-directed busulfan (BU) dosing can improve allogeneic hematopoietic stem cell transplantation outcomes, there is still large variability in BU exposure with test dose alone due to changes in BU clearance caused by drug interactions. We conducted a single-arm phase II trial using the combined test dose and therapeutic drug monitoring strategy (PK-guided group) and compared the outcomes with an external historical cohort receiving a fixed-dose (fixed-dose group). The first eight and second eight doses were adjusted based on the area under the blood concentration-time curve (AUC) of the test and first doses, respectively, targeting a total AUC of 82.1 mg·h/L. All patients received either BU and cyclophosphamide conditioning (BU/CY) or fludarabine (FLU)-containing conditioning. The BU clearance at the first dose decreased more in patients receiving FLU than in those receiving BU/CY; however, BU clearance also declined over time in patients who received BU/CY. The simulated total AUC (sAUC) with test dose only was significantly higher in patients who received FLU than in those who received BU/CY, but sAUC with the combined strategy was comparable. The 100-day progression-free survival was 85.5% (95% confidence interval [CI]: 71.9–92.8%), and was not inferior to that in the fixed-dose group. For the FLU-containing regimens, the PK-guided group showed decreased relapse (0.0% vs. 26.9%, p = 0.03), and favorable overall survival (75.1% vs. 57.0%, p = 0.07) at 1 year. The combined strategy effectively controlled the BU exposure close to the target levels, potentially improving efficacy, especially in patients receiving the FLU-containing regimen. Clinical evaluation of efficacy of dose-modified intravenous busulfan in allogeneic hematopoietic stem cell transplantation for hematological malignancy (#UMIN000014077, June 15th, 2014). [ABSTRACT FROM AUTHOR]

Summary: Patients with immune thrombocytopenic purpura (ITP) often receive corticosteroids as a first‐line treatment strategy. The ability to predict the therapeutic response to corticosteroids before initiating treatment would reduce the risk of adverse events, but biomarkers of this parameter have not yet been established. Here, in a single‐centre, retrospective, cohort study of 127 ITP patients who received corticosteroids as first‐line treatment, we compared several characteristics and test results between those patients with a favourable response to corticosteroids (responder cohort, n = 68) and those with a poor response to corticosteroids (non‐responder cohort, n = 59) to identify potential biomarkers that were predictive of corticosteroid response. We extracted six factors as indicative of poor response to corticosteroid therapy for ITP: old age (≥81 years) (odds ratio [OR], 2.44; p = 0.02); low platelet count (<9 × 109/L) (OR, 2.25; p = 0.02); high level of platelet‐associated IgG (≥445 ng/107cells) (OR, 3.95; p < 0.01), high platelet distribution width (≥ 14.0 g/dL) (OR, 2.00; p = 0.03), high lymphocyte‐to‐monocyte ratio (≥ 3.52) (OR, 1.40, p = 0.04), and low megakaryocyte count in bone marrow (< 85.5/μl) (OR, 1.72; p = 0.04). Thus, our present data support the fact that these six factors are useful biomarkers for predicting corticosteroid response in patients with ITP. [ABSTRACT FROM AUTHOR]

We conducted a phase II trial to prospectively evaluate the efficacy and safety of bortezomib-cyclophosphamide-dexamethasone (VCD) induction, autologous stem cell transplantation (ASCT), VCD consolidation, and bortezomib maintenance in transplant-eligible newly diagnosed multiple myeloma (NDMM) patients in Japan (UMIN000010542). From 2013 to 2016, 42 patients with a median age of 58 (range 42–65) years with NDMM were enrolled in 15 centers. The primary endpoint was the complete response (CR) /stringent CR (sCR) rate after transplantation, and overall/progression-free survival rates were also evaluated. Following induction therapy, the overall response rate was obtained in 71% of patients, including a CR/sCR of 10% and a very good partial response (VGPR) of 26%. Twenty-six of the 42 patients completed ASCT following the protocol and CR/sCR and VGPR rate 100 days after ASCT was 26% and 17%, respectively. During consolidation therapy, 3 of the 24 patients achieved deeper responses. Eight of the 18 patients completed 2-year bortezomib maintenance without disease progression and grade 3/4 toxicities. Five patients were VGPR or partial response after ASCT but maintained response with 2-year bortezomib maintenance. Two-year overall and progression-free survival rates were 92.5% (95% confidence interval [CI]: 78.5%−97.5%) and 62.6% (95% CI: 45.8%−75.5%), respectively. Grade 3/4 toxicities (≥ 10%) included neutropenia (19%) and anemia (17%) in induction, and thrombocytopenia (29%) in consolidation. VCD induction/consolidation and bortezomib maintenance with ASCT for NDMM resulted in a high CR/sCR rate and provided good overall/progression-free survival in Japan. [ABSTRACT FROM AUTHOR]

Serum ferritin, a marker of systemic iron status, is considered a prognostic factor for patients with myelodysplastic syndromes (MDS), despite the lack of supporting evidence. We investigated the association between serum ferritin levels at diagnosis and the prognoses of Japanese MDS patients with bone marrow blasts < 5% and peripheral blood blasts < 2%. Three hundred and ninety patients with cytopenia were registered prospectively in the multicenter database, among whom 107 patients with MDS (72 males and 35 females, with a median age of 70 years) met the eligibility criteria. The median serum ferritin level at diagnosis was 204 ng/mL; we divided the cohort into low (n = 56) and high (n = 51) ferritin groups using a cutoff of 210 ng/mL. Kaplan-Meier analyses revealed that the 3-year overall survival (OS) of the high ferritin group was significantly shorter than that of the low ferritin group (66% and 79%, respectively). The cumulative incidences of leukemic progression were similar between the groups. On multivariate analysis, age, blast percentage, cytogenetic abnormalities, and serum ferritin levels at diagnosis were independently associated with OS in our patients. Thus, modest elevations of ferritin levels at diagnosis may influence the prognoses of patients with MDS who have low blast counts. [ABSTRACT FROM AUTHOR]

Angioimmunoblastic T-cell lymphoma (AITL) is a common subtype of peripheral T-cell lymphoma with an aggressive clinical course and poor prognosis after conventional chemotherapy, for which there is no current standard of care. We describe here an 87-year-old woman with AITL, whose clinical diagnosis was complicated by the presence of B immunoblasts positive for Epstein-Barr virus in the lymph nodes and monoclonal plasma cells in the bone marrow at initial presentation. Rebiopsy of the lymph node led to the correct diagnosis of AITL with concurrent smoldering plasma cell myeloma. She was treated with several courses of conventional chemotherapy, resulting in progressive disease, and then switched to the immunomodulatory drug lenalidomide, which used in Japan for the treatment of multiple myeloma. Lenalidomide was effective in controlling both AITL and plasma cell myeloma. [ABSTRACT FROM AUTHOR]

The Japanese National Research Group on Idiopathic Bone Marrow Failure Syndromes has been conducting prospective registration, central review, and follow-up study for patients with aplastic anemia and myelodysplastic syndrome (MDS) since 2006. Using this database, we retrospectively analyzed the prognosis of patients with MDS. As of May 2016, 351 cases were registered in this database, 186 of which were eligible for the present study. Kaplan-Meier analysis showed that overall survival (OS) curves of the five risk categories stipulated by the revised international prognostic scoring system (IPSS-R) were reasonably separated. 2-year OS rates for the very low-, low-, intermediate-, high-, and very high-risk categories were 95, 89, 79, 35, and 12%, respectively. In the same categories, incidence of leukemic transformation at 2 years was 0, 10, 8, 56, and 40%, respectively. Multivariate analysis revealed that male sex, low platelet counts, increased blast percentage (>2%), and high-risk karyotype abnormalities were independent risk factors for poor OS. Based on these data, we classified Japanese MDS patients who were classified as intermediate-risk in IPSS-R, into the lower risk MDS category, highlighting the need for careful assessment of treatments within low- and high-risk treatment protocols. [ABSTRACT FROM AUTHOR]

Pregnancy with paroxysmal nocturnal hemoglobinuria (PNH) is associated with significant risk of complications, such as life-threatening thrombosis. Recently, eculizumab has come into clinical use and revolutionized the treatment of PNH. However, clinical information regarding eculizumab use for PNH during pregnancy is limited. The present report describes pregnancies with PNH treated with eculizumab that were registered with the Japan PNH study group and reviews the literature. In case 1, the patient received eculizumab throughout pregnancy and delivered a healthy neonate at term, although breakthrough hemolysis occurred at 20 weeks of gestation. In case 2, the patient discontinued eculizumab before pregnancy and developed preeclampsia at 27 weeks of gestation. She received eculizumab and delivered a preterm, but healthy, neonate by cesarean section. In case 3, the patient received eculizumab from 18 weeks of gestation and delivered a healthy neonate at term without any complications. Reports of 11 pregnant women treated with eculizumab were identified in the literature. Of 14 pregnancies, including our own cases, breakthrough hemolysis and preeclampsia occurred in five and two cases, respectively. There were no thrombotic complications, maternal or neonatal deaths, or fetal structural abnormalities. Thus, eculizumab appears to be safe and effective for managing PNH during pregnancy. [ABSTRACT FROM AUTHOR]

The prognosis of follicular lymphoma (FL) is significantly associated with host immunity and tumor microenvironment. Lymphopenia has been identified as a negative prognostic factor for FL. The association between monocytosis and progression-free survival (PFS) in FL remains controversial. It is unknown whether the ratio of peripheral blood absolute lymphocyte count to absolute monocyte count (ALC/AMC) at diagnosis is associated with FL prognosis. We studied 99 consecutive patients with FL who were treated with rituximab-containing chemotherapy at Kitano Hospital or Kyoto University Hospital between 2000 and 2012. We analyzed individual variables associated with the ALC/AMC ratio before treatment, as well as known prognostic factors of FL, and found that an ALC/AMC ratio of 4.7 was the best cut-off value for PFS. Kaplan-Meier analysis showed that a decreased ALC/AMC ratio was associated with inferior PFS ( P = 0.022). Multivariate analysis showed that a decreased ALC/AMC ratio was a significant poor prognostic factor independent of other variables (hazard ratio, 2.714; 95 % confidence interval, 1.060-6.948; P = 0.037). The ALC/AMC ratio before treatment may be a significant prognostic factor predicting PFS of FL. [ABSTRACT FROM AUTHOR]

High-dose chemotherapy (HDT), together with autologous stem cell transplantation (ASCT), plays an important role in the treatment of diffuse large B cell lymphoma (DLBCL), especially as second-line therapy. However, its significance in up-front settings remains to be elucidated. In our institute, patients with DLBCL in both the high-intermediate and high international prognostic index (IPI) groups initially underwent CHOP/R-CHOP treatment followed by HDT/ASCT at upfront settings between 2002 and 2011. We retrospectively analyzed 25 patients who were all treated with upfront HDT/ASCT. We excluded one patient who failed to undergo transplantation because of primary refractory disease from the analysis. The median follow-up was 77 months (range 17-110 months). Five-year overall survival (OS) and progression-free survival (PFS) were 91.7 and 79.2 %, respectively, which were higher than the equivalents in previous studies. The OS and PFS in the high-risk group were lower than those in the high-intermediate group. Treatment-related mortalities or fatal complication were not observed. Our results confirm that HDT/ASCT for high-risk aggressive lymphoma is a feasible and promising therapy, but patients with high IPI continued to have poor prognoses; improvements in treatment strategy are clearly needed. Since HDT/ASCT is an aggressive treatment option associated with long-term complications, we need to identify patient groups that will gain the maximum benefit from HDT/ASCT in the upfront setting. [ABSTRACT FROM AUTHOR]

Fusarium spp. cause a broad spectrum of infection and are relatively resistant to most antifungal agents, leading to unfavorable prognosis, especially in immunocompromised patients. Several reports have shown synergism among amphotericin B, voriconazole (VRC), terbinafine (TRB), and other antifungal agents in vitro, but the most efficacious combination remains to be elucidated. We report the first case of disseminated Fusarium solani infection successfully treated by combination therapy of VRC and TRB accompanied by surgical resection of endocardial lesions. We also review 15 case reports of combination antifungal therapy for fusariosis and 6 case reports of Fusarium endocarditis. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndrome ( MDS) is a clonal disorder arising from an alteration in multipotent stem cells, which lose the ability of normal proliferation and differentiation. Disease progression occurs in approximately 30% MDS cases. Specific chromosomal alterations seem responsible for each step in the evolution of acute myeloid leukemia ( AML). Multiple genetic aberrations occur during the clonal evolution of MDS; however, few studies report the presence of the Philadelphia (Ph) chromosome. We report a rare case of Ph-positive AML, which evolved during the course of low-risk MDS. The patient, a 76-year-old man with mild leukocytopenia, was diagnosed with MDS, refractory neutropenia ( RN). After 1.5 yr, his peripheral blood and bone marrow were suddenly occupied by immature basophils and myeloblasts, indicating the onset of AML. A bone marrow smear showed multilineage dysplasia, consistent with MDS evolution. Chromosomal analysis showed an additional t(9;22)(q34;q11) translocation. Because progression occurred concurrently with emergence of the Ph chromosome, we diagnosed this case as Ph-positive AML with basophilia arising from the clonal evolution of MDS. The patient was initially treated with nilotinib. A hematological response was soon achieved with disappearance of the Ph chromosome in the bone marrow. Emergence of Ph-positive AML in the course of low-risk MDS has rarely been reported. We report this case as a rare clinical course of MDS. [ABSTRACT FROM AUTHOR]

The incidence of Hodgkin lymphoma (HL) is paradoxically increasing in the combination anti-retroviral therapy (cART) era. However, there has been no nationwide survey of human immunodeficiency virus (HIV)-associated HL (HIV-HL) in Japan. We retrospectively examined the clinical characteristics and outcomes of 19 newly diagnosed HIV-HL patients at 11 HIV/AIDS and hematology regional hospitals in Japan between 1991 and 2010. At the time of HL diagnosis, 79 % of patients were receiving cART. All the patients, but one received HL diagnoses in the cART era. The median CD4+ cell count at HIV-HL diagnosis was 169/μl. Mixed-cellularity classical Hodgkin lymphoma was the most common subtype occurring in 68 % of the patients; 89 % of the patients were positive for Epstein-Barr virus. Of these 19 patients, 84 % were in advanced stages, with bone marrow involvement observed in 47 % of the patients; 58 % had extranodal sites. All the treated patients were given cART concurrent with HL therapy. The complete remission rate of the treated patients was 87 %. The median OS of the entire cohort was 17 months. These results suggest that the characteristics of HIV-HL in Japan are more aggressive than those of non-HIV-associated HL in Japan, but standard chemotherapy is effective and feasible. [ABSTRACT FROM AUTHOR]

We conducted a multicenter, retrospective study to determine the anatomical distribution and prognostic factors of gastrointestinal (GI) follicular lymphoma (FL). This study included 125 patients with stage I and II1 GI-FL. Of the 125 patients, the small intestine was examined in 70 patients, with double-balloon endoscopy and/or capsule endoscopy. The most frequently involved GI-FL site was the duodenal second portion (DSP) (81%), followed by the jejunum (40%); 85% of patients with involvement of the DSP also had jejunal or ileal lesions. The absence of abdominal symptoms and macroscopic appearance of multiple nodules were significantly present in the DSP-positive group. During a median follow up of 40 months, six patients showed disease progression. Patients with involvement of the DSP had better progression-free survival (PFS) than those without such involvement ( P = 0.001). A multivariate analysis revealed that male sex, the presence of abdominal symptoms, and negative involvement of the DSP were independently associated with poor PFS. In conclusion, most patients with GI-FL have duodenal lesions associated with multiple jejunal or ileal lesions. Gastrointestinal follicular lymphomas involving the DSP might be a distinct entity showing a favorable clinical course. ( Cancer Sci 2011; 102: 1532-1536) [ABSTRACT FROM AUTHOR]

Hemophagocytic lymphohistiocytosis (HLH), which occurs during the early period following allogeneic hematopoietic stem cell transplantation (HSCT), is often difficult to diagnose. It is characterized by severe clinical manifestations and high mortality. Despite current therapeutic approaches, outcomes remain poor. Here, we summarize the cases of two patients who experienced engraftment failure and subsequently developed hematopoietic stem cell transplantation-hemophagocytic lymphohistiocytosis (HSCT-HLH). Both patients had high-risk hematological malignancies for which they underwent umbilical cord blood transplantation (UCBT) at our institution. Based on the presence of massive hemophagocytosis in their bone marrow specimens and the results of chimerism analysis, diagnosis of HSCT-HLH was made in both cases. A single infusion of low-dose etoposide was administered immediately to each patient. Four days after the injection, therapeutic efficacy was evaluated. As both cases showed an insufficient response to etoposide, we added vincristine and a medium dose of prednisolone. Clinical symptoms rapidly improved and stable engraftments were observed within a week. The first and second patients were alive 1008 and 232 days after UCBT, respectively. The combined use of low-dose etoposide and vincristine plus prednisolone appears to be a promising treatment option for HSCT-HLH, without serious adverse side effects. [ABSTRACT FROM AUTHOR]

Background aims. Cell therapy with mesenchymal stromal cells (MSC) has been reported recently as a promising treatment for severe acute graft-versus-host disease (GvHD). Methods. We designed a pilot study to treat severe hepatic or gut GvHD using MSC derived from only the donor and cultured without bovine serum. Because the number of cultured MSC is smaller using this method, we planned to treat patients by intra-arterial regional administration directly to the target organs. Results. Three patients were enrolled, and the MSC could be expanded using donor serum. There were no obvious side-effects immediately after arterial injection. The maximum response was partial in one of three patients and did not continue for more than 2 months. Idiopathic pneumonia syndrome developed in two of the three patients. Conclusions. A single local arterial MSC injection was unable to save these patients’ lives and so might not be more effective than multiple systemic intravenous MSC injection. Further clinical research and additional strategies are required to develop appropriate methods for using MSC to achieve extended remission of GvHD. [ABSTRACT FROM AUTHOR]

Adult T-cell leukemia (ATL) is a peripheral T-cell neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). The prognosis of ATL, especially the acute and lymphoma subtypes, is poor with conventional and high-dose chemotherapy. The effectiveness of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for ATL has been reported, suggesting the presence of a graft-versus-leukemia (GVL) effect against this malignancy. To identify the target antigens associated with tumor rejection, we used SEREX (serological identification of antigens by recombinant cDNA expression cloning) to screen ATL complementary DNA expression libraries with sera from an ATL patient who had a GVL response after allo-HSCT. Among the isolated clones, autocrine motility factor receptor (AMFR), which encodes a glycosylated transmembrane protein, was found to have selective reactivity with the sera obtained during tumor regression. Real-time reverse transcription polymerase chain reaction analysis for AMFR showed highest expression in the testis among normal tissues. Furthermore, aberrant AMFR expression was found in at least some ATL patients. Taken together, these findings suggest that AMFR may be one of the GVL antigens that provoke effective antitumor immunity against ATL in allogeneic settings. [ABSTRACT FROM AUTHOR]

Using anti-Tac (antl-α chain) and 2R-B (anti-β chain) antibodies, we studied the roles of IL-2 receptor subunits (α and β chains) in the formation of IL-2 and high-affinity IL-2 receptor complex, which is the Initial event of IL-2 induced T cell growth. Hlgh-afflnity IL-2 binding which was undetectable in the presence of 2R-B antibody at 4°C became fully detectable when examined at 37°C, which explained the lack of inhibition by 2R-B antibody of IL-2-lnduced proliferation of the cells expressing high-affinity IL-2 receptor. We further studied the mechanism of the ‘reappearance’ of high-affinity IL-2 binding in the presence of 2R-B antibody. The addition of IL-2 to the cells preincubated with radiolabeled or fluorescence-labeled 2R-B antibody resulted in a marked decrease In the antibody bound to the cells expressing high-affinity IL-2 receptor at 37°C. This decrease was blocked by the presence of anti-Tac antibody, which inhibited IL-2 binding to α chain, but not by 7G7/B6 antibody, which recognized a non-IL-2 binding site of its chain. Furthermore, the decrease in cell-bound 2R-B antibody was not due to the internalization of β chain-2R-B antibody complex, because the amount of cell-bound Mlk-β antibody recognizing a non-IL-2 binding epltope of β chain remained unchanged, nor to the inhibition by simple competitive binding of IL-2 molecules to β chain as judged from comparative studies of competitive binding Inhibition. Taking these data together, the reappearance of high-affinity IL-2 binding was considered to be caused by the replacement of 2R-B antibody at the IL-2 binding site of β chain by α chain-mediated IL-2, and it was strongly suggested that α chain -IL-2 complex has a key role in the formation of the ternary complex of IL-2 and high-afflnlty IL-2 receptor, α chain may function as a dimension converter of IL-2 to effectively deliver IL-2 molecules to a relatively small number of β chains in the dynamics of the formation of hlgh-afflnity IL-2 binding in T cells. [ABSTRACT FROM PUBLISHER]

Summary. A 69-year-old man presented with right neck tumour. Primary thyroid MALT lymphoma occurring in Hasimoto's thyroiditis was diagnosed. He was also diagnosed to have gastric cancer with Helicobacter pylori infection. After subtotal gastrectomy by itself, thyroid lymphoma became smaller transiently. Then the patient was treated with H. pylori eradication therapy, resulting in the complete disappearance of lymphoma. Although H. pylori organisms were not detected in the lymphoma tissue by polymerase chain reaction (PCR), it might be implicated in the pathogenesis of extragastric MALT lymphomas. [ABSTRACT FROM AUTHOR]