Persistently Low IgG2 Levels in a Subset of Patients Following Hematopoietic Cell Transplantation.

BACKGROUND: Infectious diseases remain a major cause of morbidity and mortality after hematopoietic cell transplantation (HCT). Secondary hypogammaglobulinemia is a risk factor for infectious diseases. Total immunoglobulin G (IgG) levels and the history of infectious diseases are an integral part of determining the indication for immunoglobulin replacement therapy. The clinical significance of IgG2 levels is not well established. Guidelines recommend using pathogen-specific IgG to evaluate patients with potential secondary immunodeficiency. However, it is difficult in practice to perform such testing. IgG2 may correlate well with pathogen-specific IgG but the clinical significance of IgG2 is not well established. METHODS: To assess the prevalence of low IgG2 levels with normal IgG after HCT, we cross-sectionally measured the levels of several immunoglobulins, including IgG, IgA, IgM, and IgG2, after HCT, and we assessed the correlation between them. RESULTS: Among 121 patients who underwent cross-sectional measurements of IgG, IgA, IgM, and IgG2 levels after HCT, 114 had normal IgG2 levels (normal IgG2 group, ≥ 100 mg/dL) and 7 had low IgG2 levels (low IgG2 group, < 100 mg/dL). These 7 patients were allogeneic HCT recipients. All 7 patients with low IgG2 had cGVHD and 4/7 patients had normal total IgG levels. CONCLUSION: IgG2 levels may be low even in patients with normal IgG levels years after allogeneic HCT. Therefore, our study suggests that when patients develop infectious diseases, especially multiple episodes, it is recommended to measure IgG2 levels to exclude the possibility of secondary hypogammaglobulinemia after allogeneic HCT.

Differentiating Between Epstein-Barr Virus-positive Lymphoid Neoplasm Relapse and Post-transplant Lymphoproliferative Disorder After Sex-mismatched Hematopoietic Stem Cell Transplantation.

After allogeneic hematopoietic stem cell transplantation (HSCT), accurate differentiation between donor-derived post-transplant lymphoproliferative disorder (PTLD) and relapse of recipient-derived lymphoproliferative disorder (LPD) is crucial for determining treatment. Conventional diagnostic approaches for PTLD include histopathological examination, flow cytometry, and chimerism analysis of bulk tumor tissue. However, these methods are inconclusive in cases in which the primary disease is an Epstein-Barr virus (EBV)-positive LPD and is of the same lineage as that of the post-HSCT LPD tumor cells. Particularly, in cases where the number of tumor cells in the tissue is low, it is difficult to determine the origin of tumor cells. In this study, we developed a new method to simultaneously detect signals using sex chromosome fluorescence in situ hybridization, immunofluorescence staining, and EBV-encoded small RNA in situ hybridization on a single section of formalin-fixed paraffin-embedded histopathological specimen. The utility of the method was validated using specimens from 6 cases of EBV-positive LPD after sex-mismatched HSCT that were previously difficult to diagnose, including Hodgkin lymphoma-like PTLD that developed after HSCT for Hodgkin lymphoma and recurrence of chronic active EBV infection. This method successfully preserved the histologic structure after staining and allowed accurate determination of tumor cell origin and lineage at the single-cell level, providing a definitive diagnosis in all cases. This method provides a powerful tool for the diagnosis of LPDs after sex-mismatched HSCT.

A single-institution pre-post comparison of subcutaneous immunoglobulin replacement therapy in allogeneic haematopoietic cell transplantation recipients.

Immunoglobulin replacement therapy (IgRT) reduces the risk of infection in hypogammaglobulinaemia secondary to chronic lymphocytic leukaemia and multiple myeloma. However, the benefit of IgRT, especially subcutaneous IgRT (ScIgRT), has not been assessed in hypogammaglobulinaemia after allogeneic haematopoietic cell transplantation (allo-HCT). We performed a pre-post comparison of the clinical impact of ScIgRT after allo-HCT in a retrospective analysis of 209 patients who underwent allogeneic HCT at our institution from 2011 to 2019. Since ScIgRT became available at our institution in April 2017, we categorized patients treated from January 2011 to March 2017 as the Pre-ScIgRT group (n = 118) and those treated from April 2017 to December 2019 as the Post-ScIgRT group (n = 91). The 2-year overall survival rate was 65% in the Pre-ScIgRT group and 81% in the Post-ScIgRT group (p = 0.02). The cumulative incidence (CI) of non-relapse mortality at 2 years was 18% and 7% (p = 0.02). There were 78 infectious events in 44 patients in the Pre-ScIgRT group and 28 such events in 19 patients in the Post-ScIgRT group. The CI of the documented infection during the observation period was between 38% and 21% (p = 0.01). Our study suggests that ScIgRT may reduce infection rates and improve prognosis after allo-HCT.

Gilteritinib in peritransplant period for relapsed or refractory FLT3-mutated acute myeloid leukemia: A case report of three patients.

Patients with relapsed or refractory acute myeloid leukemia (RR-AML) with mutations of FMS-like tyrosine kinase 3 (FLT3) have a poor prognosis even after allogeneic hematopoietic cell transplantation (allo-HCT). Multiple FLT3 inhibitors, including gilteritinib, have been developed and serve as treatment options for RR-AML. Here, we describe three cases of FLT3 mutated RR-AML that were successfully treated with gilteritinib administration before and after allo-HCT. Gilteritinib treatment before HCT was helpful in achieving remission. However, HCT often resulted in mild liver damage, and careful introduction of gilteritinib after HCT at a lower dose may be helpful for its safe usage. The three cases discussed had a successful clinical outcome in terms of disease control as well as the management of side effects associated with gilteritinib treatment.

A case of severe oral mucosal GVHD induced by heterologous SARS-CoV-2 vaccination after cord blood transplantation.

Patients who have undergone hematopoietic cell transplantation (HCT) are at a higher risk of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection than the general population. Therefore, early vaccination is recommended for post-transplant patients. Although exacerbation of chronic graft-versus-host disease (cGVHD) after the initial vaccination has been reported, it is unknown whether severe cGVHD occurs when different RNA vaccines are combined. We treated a patient who developed severe oral mucosal cGVHD after receiving two different RNA vaccines. Visual inspection showed that the patient presented with typical mucocutaneous cGVHD, and cGVHD in this case responded well to low-dose steroids compared to common oral GVHD exacerbations. Histopathological findings revealed T cell, B cell, and conspicuous neutrophil infiltration. Multiple doses of SARS-Cov2 vaccination are required in post-transplant recipients. In conclusion, it is essential to obtain the vaccination history of allo-HSCT recipients with cGVHD exacerbation. Furthermore, reviewing the pathological findings may help treat patients with lower doses of steroids.

A case of multiple myeloma with pancreatic involvement diagnosed via endoscopic ultrasound-guided fine needle aspiration.

This report highlights the importance of considering multiple myeloma in the differential diagnosis of a pancreatic tumor with bone lesions. sampling not only from the pancreatic lesion but also from bone lesions may reach an accurate diagnosis.

Antiemetic Strategies in Patients Who Undergo Hematopoietic Stem Cell Transplantation.

Hematopoietic stem cell transplantation (HSCT) is an integral part of the treatment strategy in patients with a hematological disorder. Chemotherapy-induced nausea and vomiting (CINV) is still an issue in patients who undergo HSCT. While several guidelines for the antiemetic therapy against CINV have been published, there is no detailed information about appropriate antiemetic drugs for each conditioning regimen in HSCT. Various studies reported that the triplet of 5-HT3RA, NK1RA, and dexamethasone appears useful in HSCT. However, each antiemetic has unique adverse effects or interactions with specific drugs. Here, we review the literature relating to clinical trials on the prevention of CINV, and summarize the information to clarify the benefit of antiemetic regimens.

The outcome of watchful waiting in patients with previously treated follicular lymphoma.

Watchful waiting (WW) is one of the standard approaches for newly diagnosed follicular lymphoma (FL) patients with low-tumor burden. However, the impact of WW in FL patients at the first progression, remains unclear. We reviewed 206 FL patients who experienced the first progression after responding to the initial treatment at our institution between 1998 and 2017. Patients were classified into either the WW cohort (132 patients) or the immediate treatment cohort (74 patients). Overall, the median follow-up from the first progression was 79.8 months (range, 2.1-227.0 months). In the WW cohort, the estimated median time to next treatment (TNT) was 19.7 months (95% confidence interval [CI], 13.4-30.2), and 76.5% (95% CI, 68.0-84.1) of the patients subsequently underwent the second-line treatment at 5 years. There was a significant difference in the median time to treatment failure in the WW cohort (72.8 months; 95% CI, 64.6-94.0) compared to the immediate treatment cohort (23.3 months; 95% CI, 13.4-38.8) (HR, 2.13; 95% CI, 1.48-3.06), whereas overall survival and the cumulative incidence of histological transformation were not significantly different between two cohorts. In a multivariate analysis, rituximab refractory status, progression of disease within 24 months from the induction of first-line therapy, and a high Follicular Lymphoma International Prognostic Index score at diagnosis were significantly associated with shorter TNT. Interestingly, 15 patients (11%) of the WW cohort experienced spontaneous tumor regression during WW, and their TNT (median, 82.1 months, 95% CI, 11.7-NA) was longer than that of the remaining patients in the WW cohort (median, 16.5 months, 95% CI, 13.0-25.4), with a significant difference (p = 0.01). The results of the present study suggested that WW could be a safe and reasonable option even at the first progression for the selected FL patients, without a negative impact on clinical outcomes.

Clinicopathological analysis of primary refractory diffuse large B-cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone chemoimmunotherapy.

BACKGROUND: Approximately 15% of patients with diffuse large B-cell lymphoma (DLBCL) experience refractory or early relapsed disease after initial rituximab-containing chemoimmunotherapy is regarded as a primary refractory disease. Although the standard treatment for relapsed DLBCL is high-dose chemotherapy and autologous stem cell transplantation (HDC-ASCT), the efficacy of this approach for primary refractory DLBCL is not well understood. We aimed to investigate the clinicopathological characteristics and outcomes of patients with primary refractory DLBCL. METHODS: Sixty-nine consecutive patients with primary refractory DLBCL who were treated at our institution were categorized as partial responders (partial response to rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone [R-CHOP] or relapse within 6 months of R-CHOP) (n = 41) or primary progressors (no response to R-CHOP) (n = 28). Survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. RESULTS: At initial diagnosis, 70% of patients had Ann Arbor stage III/IV disease, 56% had non-germinal center B-cell-like type DLBCL, and 42% had double-expressor lymphoma (MYC and BCL2 expression). The 3-year overall survival rate was significantly poorer in the primary progressors group than in the partial responders' group (15% vs. 48%, p < 0.001). Four of 17 patients treated with HDC-ASCT were primary progressors; only one patient survived without relapse. Although double-expressor lymphoma status did not significantly impact overall survival among all patients (p = 0.794), it was identified as an independent poor prognostic factor in HDC-ASCT-treated patients (p = 0.002). CONCLUSIONS: We identified a subgroup of patients with primary refractory DLBCL who may not benefit from current treatment strategies. Further treatment development is needed to improve the outcomes of these patients.

Clinicopathological factors and tumor microenvironment markers predicting watch-and-wait discontinuation in 82 patients with follicular lymphoma.

OBJECTIVES: In this study, we aimed to determine the clinicopathological factors influencing the treatment-free period in patients with follicular lymphoma (FL) using a watch-and-wait (WW) strategy. METHODS: We retrospectively assessed histopathological parameters of 82 patients with FL. RESULTS: The median time from diagnosis to WW discontinuation was 62 months (range, 3-138), and median follow-up was 86 months (range, 3-183). Intermediate or high-risk Follicular Lymphoma International Prognostic Index score (P = .012), non-duodenal-type (P = .011), higher numbers of interfollicular CD4+ (P = .038) and intrafollicular FOXP3+ cells (P = .024) in the tumor microenvironment, and Ki-67 index ≥10% (P = .031) were significant adverse factors for WW discontinuation in univariate analyses. CONCLUSION: Patients with adverse factors for WW discontinuation should be carefully observed during follow-up.

The role of local radiotherapy following rituximab-containing chemotherapy in patients with transformed indolent B-cell lymphoma.

OBJECTIVES: This study aimed to evaluate the outcomes of local radiotherapy (LRT) in patients with histologic transformation (HT) following rituximab-containing chemotherapy. METHODS: We retrospectively analysed 92 patients with biopsy-confirmed HT undergoing rituximab-containing chemotherapy at our institution between 2003 and 2015. RESULTS: Of the 36 patients with limited-stage disease at diagnosis of HT, 29 (78%) received LRT. The estimated 5-year progression-free survival (PFS) rate was significantly better in patients who underwent LRT than in those who did not (93% and 42%, respectively; P < 0.05). Multivariate analyses employing age, sex, performance status, LRT and treatment response demonstrated that LRT was an independent prognostic factor for PFS (hazard ratio [HR]: 11.8; 95% confidence interval [CI]: 1.28-108.1; P < 0.05). Of the 32 patients who underwent LRT for HT lesion treatment, 31 (97%) did not show disease progression within radiation fields; among them, 27 patients (84%) survived without disease progression during the follow-up period. One patient developed hypothyroidism due to LRT; the others had no acute or late-onset complications of LRT. CONCLUSIONS: Our data support the recommendation of LRT for HT lesion treatment following rituximab-containing chemotherapy in select patients with localised HT, as a rational treatment approach with potentially limited toxicity.

Transformation Scoring System (TSS): A new assessment index for clinical transformation of follicular lymphoma.

Although histologic analysis is the gold standard for diagnosing follicular lymphoma (FL) transformation, many patients are diagnosed with transformation by clinical factors as biopsy specimens often cannot be obtained. Despite the frequency of clinical diagnosis, no clinical assessment tool has yet been established for FL transformation in the rituximab era. We derived and validated a transformation scoring system (TSS) based on retrospective analyses of 126 patients with biopsy-proven FL and histologic transformation (HT) at two hospitals of the National Cancer Center of Japan. In the derivation set (76 patients), the detailed analyses of the clinical characteristics at disease progression showed that lactate dehydrogenase (LDH) elevation, focal lymph nodal (LN) enlargement, hemoglobin <12 g/dl, and poor performance status (PS) (2-4) were associated with HT. The weights of these variables were decided based on the regression coefficients. Next, we constructed a TSS encompassing the above four factors: LDH, (> upper limit of normal [ULN], ≤ULN ×2) (1 point), (≥ULN ×2) (2 points); focal LN enlargement, (≥3 cm, <7 cm) (1 point), (≥7 cm) (2 points); hemoglobin <12 g/dl (1 point); poor PS (2 points). We identified a high positive predictive value (PPV) (96.4%) and negative predictive value (NPV) (85.4%) for diagnosing HT when a cutoff score of 2 was selected for our TSS. In an external validation set (50 patients), the probability of HT was high with scores ≥2 (PPV, 93.3%; NPV, 82.9%). We developed a TSS that offers a simple, yet, valuable tool, for diagnosing HT, especially in patients who cannot undergo biopsy.

Non-diffuse large B-cell lymphoma transformation from follicular lymphoma: a single-institution study of 19 cases.

Diffuse large B-cell lymphoma (DLBCL) is the most common histological transformation (HT) of follicular lymphoma (FL). Other types of HT are very rare, and their incidence, histopathology, and patient outcomes have not been sufficiently described. Here, we assessed the clinicopathological characteristics of 19 cases of non-DLBCL HT of FL in a single institution in Japan to advance the understanding of the disease. Among 889 consecutive patients diagnosed with FL between 2000 and 2018, 191 suffered HT (21%). The median follow-up period was 94 months (range = 3-225). A total of 172 patients (90%) had DLBCL transformation, whereas the remaining 19 patients (10%) exhibited non-DLBCL transformation. In the latter cases, the following diagnoses were made based on morphology, immunohistochemistry, flow cytometry, and fluorescence in situ hybridization analyses: classic Hodgkin lymphoma (7 patients; 4%); high-grade B-cell lymphoma (HGBL) with MYC and BCL2 rearrangements (4 patients; 2%); HGBL, not otherwise specified (4 patients; 2%); B-cell lymphoblastic leukemia/lymphoma (2 patients; 1%); anaplastic large-cell lymphoma-like lymphoma (1 patient; 0.5%); and plasmablastic lymphoma (1 patient; 0.5%). Epstein-Barr virus-encoded RNA-1 did not associate with HT in any of the cases tested (n = 8). Patients with non-DLBCL transformation showed poor outcomes, with a median overall survival of 13 months (range = 2 days-107 months); 10 of the patients (53%) died of HT. In conclusions, non-DLBCL transformation was observed in 10% of patients with HT from FL. Our data show that timely, accurate, and comprehensive histopathological diagnosis is needed to ensure optimal treatment and improve the outcome of these patients.

Immunohistochemical CD20-negative change in B-cell non-Hodgkin lymphomas after rituximab-containing therapy.

CD20- change after rituximab-containing therapy is considered one of the main reasons of rituximab resistance of B-cell non-Hodgkin lymphomas (B-NHLs). However, the clinicopathological characteristics of B-NHL with CD20- change are not entirely understood. In this study, 252 B-NHL patients who were CD20+ at initial diagnosis, whose diseases relapsed or were refractory after rituximab-containing therapy, and who were re-biopsied between 2000 and 2018, were included. The median number of rituximab administration was 11 (range, 1-48). Completely negative (cCD20-) and partially negative (pCD20-) change of CD20 was observed in 49 (20%) and 16 (6%) cases, respectively. Among cCD20- and pCD20- cases, 74% and 62% of the cases changed to CD20- at the second relapse or later, respectively. Overall survival was significantly shorter in cCD20- follicular lymphoma (FL) cases than in CD20+ FL cases. Seven histopathological patterns, such as CD20- change without histological change, histological transformation (HT) to CD20- diffuse large B-cell lymphoma, and proliferation of plasmablastic/plasmacytoid tumor cells, were associated with CD20- change. HT occurred more frequently in FLs with CD20- change than in FLs continuously expressing CD20 (P < 0.0001), regardless of the timing of HT. Nine out of 25 cases (36%) showed regain or heterogeneous regain of CD20 expression. In conclusion, 20% and 6% of the 252 B-NHL cases show cCD20- and pCD20- changes with 7 histological patterns after rituximab-containing therapy. Because changes in morphology and CD20 expression after rituximab-containing therapy vary, and recovery of CD20 expression is not rare, careful follow-up and re-biopsy in B-NHL patients are recommended.

A comparison of clinical staging using the Lugano versus Ann Arbor classifications in Japanese patients with Hodgkin lymphoma.

AIMS: The Lugano classification is a novel staging system for lymphomas established in 2014. In this staging system, 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) was formally incorporated into standard staging for FDG-avid lymphomas, including Hodgkin lymphoma (HL). We retrospectively analyzed patients with HL who were newly diagnosed and treated at our institution to evaluate the utility of the Lugano classification compared to the Ann Arbor classification in Japanese patients with this type of lymphoma. METHODS: Patients newly diagnosed with HL between 2005 and 2011 were identified through our departmental database. Data from neck-chest-abdomen-pelvis CT scans, BM examinations, and FDG-PET/CT that were routinely performed for staging at our clinical practice were retrieved and analyzed. RESULTS: Fifty-four patients with a median age of 35.5 years (range: 15-78 years) were investigated in this retrospective study. The Lugano stage matched the Ann Arbor stage in 46 patients (85%). Six patients (11%) were upstaged while two (4%) were downstaged per the Lugano classification. Four patients (7%) were converted from early stage to advanced stage, but none was converted in the reverse. Among 11 patients (20%) with PET-positive bone/bone marrow lesions, only one (2%) exhibited biopsy-proven bone marrow involvement of HL cells. CONCLUSION: Our data revealed a high concordance rate between the Lugano and Ann Arbor staging system in Japanese patients with HL. Because of its low diagnostic value, routine bone marrow examination might be unnecessary for staging when FDG-PET/CT is used as a substitute.

EBV-encoded RNA1-positive cells in the bone marrow specimens of patients with EBV-negative lymphomas and sarcomas.

Epstein-Barr virus (EBV) infection is associated with pathogenesis of various cancers, including extranodal natural killer/T-cell lymphoma, nasal type (ENKL). ENKL tumor cells are positive for EBV-encoded RNA1 (EBER1), which is the most useful marker to identify ENKL tumor cells in histopathology. Currently, EBER1 in situ hybridization (ISH) is recommended to evaluate bone marrow (BM) involvement of ENKL. However, the actual burden of EBER1-positive cells in normal BM specimens remains unclear. In the present study, we performed EBER1 ISH on 111 BM specimens, which were obtained during an initial staging procedure in patients with EBV-negative cancers and were also negative for BM involvement. One or more EBER1-positive cells per whole specimen were observed in 38 specimens (34%). The number of EBER1-positive cells was distributed as follows: single positive cell, n = 17; two positive cells, n = 13; three positive cells, n = 3; and four positive cells, n = 5. These findings suggest that four or fewer EBER1-positive cells can be observed in BM specimens of patients with non-EBV-related cancers. The clinical implications of a small number of EBER1-positive cells in BM specimens of patients with ENKL should be evaluated in further studies.

Clinicopathological characteristics of diffuse large B-cell lymphoma involving small and large intestines: an analysis of 126 patients.

We analyzed the clinicopathologic characteristics of 136 intestinal diffuse large B-cell lymphomas (DLBCLs) among 126 patients. The DLBCL sites were categorized as: duodenum (n = 23), ileocecal region (n = 63), other small intestine (n = 29), rectum (n = 7), and other large intestine (n = 14). Patients with DLBCLs of the ileocecal region or other small intestine frequently underwent surgery for ileus or perforations (P < 0.001), were predominantly male (P = 0.042), and had a higher incidence of limited-stage disease (P = 0.001), lower International Prognostic Index (P = 0.015), and lower incidence of lactate dehydrogenase elevation (P = 0.007) than those with DLBCLs of other regions. Half of the intestinal DLBCLs exhibited the germinal center B-cell phenotype. A low-grade B-cell lymphoma background was found in 21% of the cases; the prevalence was significantly lower in the ileocecal region (13%, P = 0.025), suggesting a higher incidence of de novo DLBCLs. Intestinal follicular lymphoma (FL) and mucosa-associated lymphoid tissue (MALT) lymphoma backgrounds were observed in 10% and 0% of the cases, respectively. Five percent (5/107) of intestinal DLBCL cases were Epstein-Barr virus-encoded RNA-1 positive. The clinicopathologic characteristics of the DLBCLs differed by region. Histologic transformation of intestinal FL was observed in around 10% of the intestinal DLBCL cases.

Mucosa-associated lymphoid tissue lymphoma with t(11;18)(q21;q21) translocation: long-term follow-up results.

Translocation (11;18)(q21;q21) is found in mucosa-associated lymphoid tissue (MALT) lymphoma, resulting in API2/MALT1 gene fusion. It is known that t(11;18)-positive MALT lymphoma shows a tendency to disseminate and be resistant to Helicobacter pylori eradication by antibiotics. However, the prognostic features including recurrence and histological transformation (HT) remain unknown. We conducted a single-institute retrospective analysis of 464 patients with newly diagnosed MALT lymphoma, evaluating the impact of t(11;18) on clinical outcomes. One hundred and six patients were screened for the translocation by fluorescence in situ hybridization and/or reverse transcriptase-polymerase chain reaction. Of these patients, 26 patients (25%) were diagnosed as MALT lymphoma with t(11;18). The patients had a significantly shortened progression-free survival (PFS at 10 years; 26% v 57%; P = 0.004) compared to those without t(11;18). However, this did not translate into overall survival or incidence of HT. We confirmed previous reports stating that t(11;18)-positive MALT lymphoma showed disseminated disease and refractoriness to H. pylori eradication therapy. Patients with t(11;18) had more frequent monoclonal gammopathy, especially of IgM subtype (31% v 8%; P = 0.008), some of which developed class switch. These findings characterize the features of t(11;18)-positive MALT lymphoma, suggesting that it comprises a distinct clinical entity of MALT lymphoma.