Search

Background: Most patients with methotrexate‐associated lymphoproliferative disorder (MTX‐LPD) show diffuse large B‐cell lymphoma (DLBCL) or classic Hodgkin lymphoma (CHL) types. Patients with MTX‐LPD often have spontaneous remission after MTX discontinuation, but chemotherapeutic intervention is frequently required in patients with CHL‐type MTX‐LPD. In this study, we examined whether programmed cell death‐ligand 1 (PD‐L1) expression levels were associated with the prognosis of MTX‐LPD after MTX discontinuation. Methods: A total of 72 Japanese patients diagnosed with MTX‐LPD were clinicopathologically analyzed, and immunohistochemical staining of PD‐L1 was performed in 20 DLBCL‐type and 24 CHL‐type MTX‐LPD cases to compare with the clinical course. Results: PD‐L1 was expressed in 5.0% (1/20) of patients with DLBCL‐type MTX‐LPD, whereas it was expressed in 66.7% (16/24) of the patients with CHL‐type MTX‐LPD in more than 51% of tumor cells. Most CHL‐type MTX‐LPD patients with high PD‐L1 expression required chemotherapy owing to exacerbations or relapses after MTX discontinuation. However, no significant differences in clinicopathologic findings at diagnosis were observed between PD‐L1 high‐ and low‐expression CHL‐type MTX‐LPD. Conclusion: PD‐L1 expression was significantly higher in patients with CHL‐type than DLBCL‐type MTX‐LPD, suggesting the need for chemotherapy in addition to MTX discontinuation in CHL‐type MTX‐LPD patients to achieve complete remission. No association was observed between PD‐L1 expression levels and clinical findings at diagnosis, suggesting that PD‐L1 expression in tumor cells influences the pathogenesis of CHL‐type MTX‐LPD after MTX discontinuation. [ABSTRACT FROM AUTHOR]

Objective: IgG4‐related disease (IgG4‐RD) is a unique inflammatory disorder in which Th2 cytokines promote IgG4 production. In addition, recent studies have implicated the Toll‐like receptor (TLR) pathway. This study was undertaken to examine the expression of TLRs in salivary glands (SGs) from patients with IgG4‐RD. Methods: SGs from 15 patients with IgG4‐RD, 15 patients with Sjögren's syndrome (SS), 10 patients with chronic sialadenitis, and 10 healthy controls were examined histologically. TLR family gene expression (TLR‐1 through TLR‐10) was analyzed by DNA microarray in the submandibular glands (SMGs). Up‐regulation of TLRs was confirmed in SGs from patients with IgG4‐RD. Finally, the phenotype of human TLR‐7 (huTLR‐7)–transgenic C57BL/6 mice was assessed before and after stimulation with TLR agonist. Results: In patients with IgG4‐RD, TLR‐4, TLR‐7, TLR‐8, and TLR‐9 were overexpressed. Polymerase chain reaction validated the up‐regulation of TLR‐7 in IgG4‐RD compared with the other groups. Immunohistochemical analysis confirmed strong infiltration of TLR‐7–positive cells in the SGs of patients with IgG4‐RD. Double immunohistochemical staining showed that TLR‐7 expression colocalized with CD163+ M2 macrophages. After in vitro stimulation with a TLR‐7 agonist, CD163+ M2 macrophages produced higher levels of interleukin‐33 (IL‐33), which is a Th2‐activating cytokine. In huTLR‐7–transgenic mice, the focus and fibrosis scores in SMGs, pancreas, and lungs were significantly higher than those in wild‐type mice (P < 0.05). Moreover, the concentration of serum IgG, IgG1, and IL‐33 in huTLR‐7–transgenic mice was distinctly increased upon stimulation with a TLR‐7 agonist (P < 0.05). Conclusion: TLR‐7–expressing M2 macrophages may promote the activation of Th2 immune responses via IL‐33 secretion in IgG4‐RD. [ABSTRACT FROM AUTHOR]

Castleman‐Kojima disease, also known as idiopathic multicentric Castleman disease with TAFRO syndrome (iMCD‐TAFRO), is a recently recognized systemic inflammatory disorder with a characteristic series of clinical symptoms, including thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O). Patients with iMCD‐TAFRO often develop severe abdominal pain, elevated alkaline phosphatase levels, and systemic inflammation, but the etiological factors are unknown. To investigate the potential role of bacterial infection in the pathogenesis of iMCD‐TAFRO, we performed polymerase chain reaction (PCR) for the bacterial 16S rRNA gene with DNA extracted from liver specimens of three patients with iMCD‐TAFRO, four patients with amyotrophic lateral sclerosis, and seven patients with inflammatory conditions. Sequencing of the PCR product showed 99% DNA sequence identity with Campylobacter jejuni in all three patients with iMCD‐TAFRO and in two patients with inflammatory conditions. Immunohistochemical and electron microscopy analyses could not identify C. jejuni in patients with iMCD‐TAFRO. The findings indicated that C. jejuni infection is not the pathological cause of iMCD‐TAFRO; however, this ubiquitous bacterium may play a role in uncontrolled systemic hypercytokinemia, possibly through the development of cross‐reactive autoantibodies. [ABSTRACT FROM AUTHOR]

Patients with rheumatoid arthritis often develop methotrexate-associated lymphoproliferative disorders ( MTX- LPD) during MTX treatment. MTX- LPD occasionally regresses spontaneously after simply discontinuing MTX treatment. In patients without spontaneous regression, additional chemotherapy is required to avoid disease progression. However, the differences between spontaneous and non-spontaneous regression have yet to be elucidated. To clarify the factors important for spontaneous regression, we analyzed the clinicopathological features of 51 patients with rheumatoid arthritis who developed MTX- LPD (diffuse large B-cell lymphoma [ DLBCL]-type [ n = 34] and classical Hodgkin lymphoma [ CHL]-type [ n = 17]). We examined the interval from MTX discontinuation to the administration of additional chemotherapy. The majority of DLBCL-type MTX- LPD patients (81%) exhibited remission with MTX discontinuation alone. In contrast, the majority of CHL-type MTX- LPD patients (76%) required additional chemotherapy. This difference was statistically significant ( P = 0.001). However, overall survival was not significantly different between DLBCL-type and CHL-type (91% vs 94%, respectively; P > 0.05). Thus, the morphological differences in the pathological findings of MTX- LPD may be a factor for spontaneous or non-spontaneous regression after discontinuation of MTX. [ABSTRACT FROM AUTHOR]

Follicular lymphoma ( FL) shows co-expression of B-cell lymphoma 2 ( BCL2) and CD10, whereas downexpression of CD10 is occasionally experienced in gastrointestinal ( GI) FL with unknown significance. Gastrointestinal FL is a rare variant of FL, and its similarity with mucosa-associated lymphoid tissue lymphoma was reported. We investigated the clinicopathological and genetic features of CD10 downexpressed ( CD10down) GI- FL. The diagnosis of CD10down FL was carried out with a combination of pathological and molecular analyses. The incidence of CD10down GI- FL was shown in 35/172 (20.3%) cases, which was more frequent than nodal FL (3.5%, P < 0.001). The difference was additionally significant between GI- FL and nodal FL when the analysis was confined to primary GI- FL (55.2% vs 3.5%, P < 0.001). Compared to CD10+ GI- FL, CD10down GI- FL significantly involved the stomach or large intestine ( P = 0.015), and additionally showed the downexpression of BCL6 ( P < 0.001). The follicular dendritic cell meshwork often showed a duodenal pattern in the CD10down group ( P = 0.12). Furthermore, a lymphoepithelial lesion was observed in 5/12 (40%) gastric FL cases, which indicated caution in the differentiation of mucosa-associated lymphoid tissue lymphoma. Molecular analyses were undertaken in seven cases of CD10down GI- FL, and an identical clone was found between CD10down follicles and CD10+ BCL2+ neoplastic follicles. In the diagnosis of cases with CD10down BCL2+ follicles, careful examination with molecular studies should be carried out. [ABSTRACT FROM AUTHOR]

Little is known about the S100B+ lymphocytes, which are unique human peripheral blood lymphocytes (PBL) containing the S100B protein. It has recently been shown that S100B is released from various types of S100B+ cells and exhibits varied cytokine-like activities. In this study, we precisely characterized the S100B+ lymphocytes of healthy adults with respect to the proportion in the whole PBL, immunophenotypes, function, and their S100B mRNA expression and also evaluated their S100B-releasing activity upon stimulation. S100B+ lymphocytes were detected in all individuals examined, and the proportion of S100B+ lymphocytes in the whole PBL ranged from 0.42% to 16.15% (mean, 4.21%). In addition, two subtypes of S100B+ lymphocytes, a CTL subtype (CD3+ CD8+ CD16-) and a NK subtype (CD3- CD8- CD16+), were detected. The majority of the CTL subtype of S100B+ lymphocytes expressed the αβ-T-cell receptor. Surprisingly, S100B mRNA was detected not only in S100B+ lymphocytes, but also in every S100B- lymphocytes, although the expression levels of S100B mRNA in S100B- lymphocytes were much lower than those of S100B+ lymphocytes. The CTL subtype of S100B+ lymphocytes exhibited blastic morphological changes, proliferated and released S100B upon stimulation with phytohemagglutinin. The NK subtype of S100B+ lymphocytes exhibited morphological NK activity when cocultivated with NK-sensitive target, K-562 cells. Thus, the CTL subtype of S100B+ lymphocytes exhibit the biological characteristics of T cells, while the NK subtype of S100B+ lymphocytes exhibit the characteristics of NK cells. These results suggest that S100B+ lymphocytes are a particular subtype of cytotoxic lymphocytes that play a unique role in antitumor immunity. [ABSTRACT FROM AUTHOR]