Histology, EBV positivity, and monoclonality of IGH are useful for predicting clinical outcomes in patients with RA-LPD.

The World Health Organization classification was used to conduct an analysis of geographic, age, sex, and lesion primarily biopsied/resected distribution of 2260 lymphoid neoplasms diagnosed during 2001-2006 throughout Japan. B-cell neoplasms accounted for 65% of all lymphoid neoplasms, T/natural killer (T/NK)-cell neoplasms for 25% and Hodgkin lymphoma for 7%. The most common type was diffuse large B-cell lymphoma (DLBCL, 33%), followed by follicular lymphoma (18%), and adult T-cell leukemia/lymphoma (ATLL, 10%). The high rate of 18% for follicular lymphoma was similar to that in Western countries (11-33%). T/NK-cell neoplasms accounted for a higher percentage of lymphoid neoplasms in Kyushu (30%) and Okinawa (38%) compared with other areas of Japan (18-20%). Among T/NK-cell neoplasms, ATLL was the most common type in Okinawa (54%) and Kyushu (59%). Extranodal NK/T cell lymphoma was the second most common type of T/NK-cell neoplasms in Okinawa (15%). This epidemiological study shows that the distribution patterns of malignant lymphoma differ especially in Kyushu and Okinawa, the endemic area of human T-cell leukemia/lymphoma virus type 1.

Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma characterized by systemic disease with polymorphous infiltrate including macrophages. Although many studies of tumor-associated macrophage (TAM) populations in various malignant tumors have been published, only a few have dealt with activation of macrophage phenotypes such as M1 and M2 in tumor tissue. Because M2 macrophages highly express CD163, we suspected that CD163 may be a useful marker for identification of activation of macrophage phenotypes in AITL. We performed a retrospective study of immunohistochemical expression using two markers for macrophages [CD68 (PG-M1), CD163] and of the correlation of these expressions with overall survival of 42 AITL patients. The number of CD68-positive cells in AITL tissues did not correlate with overall survival (P= 0.59), whereas the number of CD163-positive cells and overall survival correlated to some extent (P= 0.08). Meanwhile, a higher ratio of CD163-positive to CD68-positive cells in AITL significantly correlated with worse overall survival (P= 0.036). Considering that this ratio reflects the proportion of macrophages polarized to the M2 phenotype, our findings indicate that activation of macrophages towards the M2 phenotype correlates with worse prognosis. Our findings indicate that the ratio of M2 macrophages expressed may be a useful marker for prognosis of AITL.

Composite lymphomas (CLs) have been reported in 1-4.7% of all lymphomas, however, CLs containing both T- and B-cell lymphomas (CTBLs) are very rare. Here, we examined the clinical and pathological features of 29 CTBLs. These CTBLs included 21 patients with angioimmunoblastic T-cell lymphoma (AITL) and diffuse large B-cell lymphoma (DLBCL), two with adult T-cell leukemia/lymphoma and DLBCL, one with AITL and Follicular lymphoma, one with Lennert lymphoma and DLBCL, one with subcutaneous panniculitis-like T-cell lymphoma and DLBCL, one with peripheral T-cell lymphoma (PTCL) and DLBCL, one with cutaneous T-cell lymphoma and DLBCL, and one with PTCL and chronic lymphocytic leukemia. Eighteen of 27 patients (67%) were shown to be Epstein-Barr virus (EBV)-encoded RNA-positive in their B-cell lymphoma component. T-cell and B-cell clonality were confirmed by flow cytometry, Southern blot analysis, and/or polymerase chain reaction (PCR). Using Southern blot analysis, clonal immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) rearrangements were detected in 11 of 21 and 15 of 24 cases, respectively. Using PCR analysis, clonal IgH and TCR rearrangements were detected in 7 of 8 and 7 of 7 Southern blot-negative cases, respectively. Our results suggested that PCR analysis was useful in diagnosing CTBL.

ObjectivesThe main histological change in rheumatoid arthritis (RA) is the villous proliferation of synovial lining cells, an important source of cytokines and chemokines, which are associated with inflammation. The aim of this study was to evaluate gene expression in the microdissected synovial lining cells of RA patients, using those of osteoarthritis (OA) patients as the control.MethodsSamples were obtained during total joint replacement from 11 RA and five OA patients. Total RNA from the synovial lining cells was derived from selected specimens by laser microdissection (LMD) for subsequent cDNA microarray analysis. In addition, the expression of significant genes was confirmed immunohistochemically.ResultsThe 14 519 genes detected by cDNA microarray were used to compare gene expression levels in synovial lining cells from RA with those from OA patients. Cluster analysis indicated that RA cells, including low- and high-expression subgroups, and OA cells were stored in two main clusters. The molecular activity of RA was statistically consistent with its clinical and histological activity. Expression levels of signal transducer and activator of transcription 1 (STAT1), interferon regulatory factor 1 (IRF1), and the chemokines CXCL9, CXCL10, and CCL5 were statistically significantly higher in the synovium of RA than in that of OA. Immunohistochemically, the lining synovium of RA, but not that of OA, clearly expressed STAT1, IRF1, and chemokines, as was seen in microarray analysis combined with LMD.ConclusionsOur findings indicate an important role for lining synovial cells in the inflammatory and proliferative processes of RA. Further understanding of the local signalling in structural components is important in rheumatology.