Current research seeks to identify subgroups of non-Hodgkin lymphoma (NHL) patients responsive to PD-1 blocking agents. Whether patients with pre-existing rheumatic diseases might constitute such a subgroup is unknown. We determined intratumoral expression of PD-1 and its ligands in lymphoma patients with pre-existing rheumatic diseases. We included 215 patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) or Sjögren’s syndrome with subsequent lymphoma and 74 diffuse large B-cell lymphoma (DLBCL) controls without rheumatic disease. PD-1 and PD-ligand immunohistochemical markers were applied on tumor tissue microarrays. The number of PD-1+ tumor infiltrating leukocytes (TILs) and proportions of PD-L1+ and PD-L2+ tumor cells and TILs were calculated and correlated with clinical data. Expression of PD-L1 in tumor cells and TILs was highest in classical Hodgkin lymphoma and DLBCL. In DLBCLs, expression of PD-1 in TILs and PD-L1 in tumor cells was similar in RA, SLE and controls. In RA-DLBCL, high expression of PD-L1 in tumor cells was significantly more common in patients with the most severe RA disease and was associated with inferior overall survival in multivariable analysis.

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that can affect multiple organs. IgG4-RD may show a variety of initial symptoms. In the oral mucosa, lesions present as inflammatory fibrosis with a large number of IgG4-positive plasma cells. Evaluating treatment is a well-known problem in IgG4-RD due to the absence of an established assessment system. There are difficulties in defining the severity of the disease, which is why treatment is primarily based on its clinical manifestations. We present a case report of localized IgG4-RD with ulcerative and proliferative manifestations on the tongue, which clinically mimicked oral squamous cell carcinoma. A tumor-like lesion on the tongue can indicate something else other than the malignant or reactive changes commonly found in the oral mucosa. Multiple differential diagnoses of these atypical oral lesions, including localized IgG4-RD, should be considered.

Several autoimmune and inflammatory conditions, such as rheumatoid arthritis (RA) and primary Sjögrens’s syndrome (pSS), have repeatedly been linked to an increased risk of malignant lymphoma [1,2]...

Interleukin‐40 (IL40) is a recently described 27 kDa cytokine encoded by C17orf99 , originally suggested to play a role in B‐cell biology, but its function is largely unknown. However, elevated serum levels have been reported in rheumatic diseases. Most published studies focus on IL40 measurements in serum/plasma using commercial sandwich ELISAs. Here we found large discrepancies between two IL40 ELISAs (Mybiosource and Abbexa), with Abbexa reporting significantly higher plasma levels. In our investigation, IL40 (Abbexa) was not elevated in patients with ANCA‐associated vasculitis, early or established rheumatoid arthritis (RA), or RA patients who had developed B cell lymphoma (RA‐L), compared to healthy donors. Yet, we found significant correlation of Abbexa IL40 levels with BAFF and APRIL. We next compared the binding of IL40 between the two commercial assays. Pre‐adsorption experiments showed that the Mybiosource capture antibody bound the same target as the Abbexa capture antibody but did not detect the same IL40. Moreover, neither assay detected the reciprocal IL40 kit reference nor mammalian expressed recombinant IL40. In contrast, a Human Protein Atlas (HPA) antibody towards the unstructured C‐terminal of IL40, despite being only partly validated by HPA, detected recombinant IL40 in Western blot and ELISA. We speculate that there may be different structural or modified forms of IL40. The discrepancy between the IL40 Abbexa results and the literature also highlights the difficulties in interpreting results from commercial antibodies and assays.

Systemic sclerosis (SSc) is an autoimmune rheumatic disease characterized by vasculopathy, inflammation, and fibrosis [1,2]. SSc is subclassified into diffuse cutaneous (dcSSc) and limited cutaneou...