Despite similarities in the involved organs, there are considerable clinical and pathological differences between IgG(4)+MOLPS and SS. Based on the clinical features and good response to glucocorticoids, we propose a new clinical entity: IgG(4)+MOLPS.

Objectives The Sjögren’s International Collaborative Clinical Alliance (SICCA) is an ongoing NIH-funded registry whose cohort ranges from those with symptoms of possible Sjögren’s syndrome (SS) to those with obvious disease. Using this database we examined associations between labial salivary gland (LSG) histopathology and other phenotypic features of SS. Methods LSG biopsy specimens from SICCA participants underwent protocol-directed histopathological assessments. Among 1726 LSG specimens exhibiting any pattern of sialadenitis, we compared biopsy diagnoses against concurrent salivary, ocular and serological assessments. Results LSG specimens included 61% with focal lymphocytic sialadenitis, (FLS; 66% of which had focus scores [FS] ≥ 1 per 4 mm2) and 38% with non-specific or sclerosing chronic sialadenitis (NS/SCS). FS ≥ 1 was strongly associated with positive serum anti-SS-A/-B, rheumatoid factor and the ocular component of SS, but not with symptoms of dry mouth or eyes. Those with positive anti-SS-A/-B were 9 times more likely to have a FS ≥ 1 (95% CI: 7.4; 11.9) than FS<1 or another pattern, while those with unstimulated whole salivary flow < 0.1 ml/min were only 2 times more likely to have a FS ≥ 1 (95% CI:1.7; 2.8) than FS<1 or another pattern, while controlling for other phenotypic features of SS. Conclusions Distinguishing FLS from NS/SCS is essential in assessing LSG biopsies, before determining FS. A diagnosis of FLS with FS ≥ 1 per 4 mm2, as compared to FLS with FS< 1 or with NS/SCS, was strongly associated with the ocular and serological components of SS and reflects SS autoimmunity.

IgG4-related disease is a new disease classification established in Japan in the 21st century. Patients with IgG4-related disease display hyper-IgG4-gammaglobulinemia, massive infiltration of IgG4+ plasma cells into tissue, and good response to glucocorticoids. Since IgG4 overexpression is also observed in other disorders, it is necessary to diagnose IgG4-related disease carefully and correctly. We therefore sought to determine cutoff values for serum IgG4 and IgG4/IgG and for IgG4+/IgG+ plasma cells in tissue diagnostic of IgG4-related disease. Patients and Methods. We retrospectively analyzed serum IgG4 concentrations and IgG4/IgG ratio and IgG4+/IgG+ plasma cell ratio in tissues of 132 patients with IgG4-related disease and 48 patients with other disorders. Result. Serum IgG4 >135  mg/dl demonstrated a sensitivity of 97.0% and a specificity of 79.6% in diagnosing IgG4-related disease, and serum IgG4/IgG ratios >8% had a sensitivity and specificity of 95.5% and 87.5%, respectively. IgG4+cell/IgG+ cell ratio in tissues >40% had a sensitivity and specificity of 94.4% and 85.7%, respectively. However, the number of IgG4+ cells was reduced in severely fibrotic parts of tissues. Conclusion. Although a recent unanimous consensus of all relevant researchers in Japan recently established the diagnostic criteria for IgG4-related disease, findings such as ours indicate that further discussion is needed.

Follistatin-related protein (FRP) ⁄ follistatin-like 1 (FSTL1) is a member of the follistatin protein family, all of which share a characteristic structure unit found in follistatin, called the FS domain. Developmental studies have suggested that FRP regulates organ tissue formation in embryos. Immunological studies showed that FRP modifies joint inflammation in arthritic disease, and modulates allograft tolerance. However, the principle physiological function of FRP is currently unknown. To address this issue, we cloned four FRP-associated proteins using a two-hybrid cloning method: disco-interacting protein 2 homolog A from Drosophila (DIP2A), CD14, glypican 1 and titin. Only DIP2A was expected to be a membrane receptor protein with intracellular regions. Overexpression of FLAG epitope-tagged DIP2A augmented the suppressive effect of FRP on FBJ murine osteosarcoma viral oncogene homolog (FOS) expression, and the Fab fragment of IgG to FLAG blocked this effect. Knockdown of Dip2a leaded to Fos gene up-regulation, and this was not affected by exogenous FRP. These in vitro experiments confirmed that DIP2A could be a cellsurface receptor protein and mediate a FOS down-regulation signal of FRP. Moreover, molecular interaction analyses using Biacore demonstrated that FRP bound to DIP2A and CD14, and also with proteins of the TGF-b superfamily, i.e. activin, TGF-b, bone morphogenetic protein 2 ⁄ 4 (BMP-2⁄ 4), their receptors and follistatin. FRP binding to DIP2A was blocked by CD14, follistatin, activin and BMP-2. FRP blocked the ligand-receptor binding of activin and BMP-2, but integrated itself with that of BMP-4. This multi-specific binding may reflect the broad physiological activity of FRP. Structured digital abstractl A list of the large number of protein-protein interactions described in this article is available via the MINT article ID MINT-7990613Abbreviations ActR-IIB, activin receptor type IIB; Akt1, V-akt murine thymoma viral oncogene homolog 1; BMP-2 ⁄ 4, bone morphogenetic protein 2 ⁄ 4; BMPR1A, bone morphogenetic protein receptor type IA; DIP2A, DIP2 disco-interacting protein 2 homolog A; Dox, doxycycline; FLRG, follistatin-related gene protein; FOS, FBJ murine osteosarcoma viral oncogene homolog; FRP, follistatin-related protein; FSTL1, follistatin-like 1; Hprt, hypoxanthine guanine phosphoribosyl transferase; Mmp3, matrix metalloproteinase 3; SPARC, secreted protein acidic and rich in cysteine; TGF-b, transforming growth factor b; TGF-bRII, transforming growth factor b type II receptor; X-a-Gal, 5-bromo-4-chloro-3-indolyl-a-D-galactopyranoside.

Multicentric Castleman's disease (MCD) is a polyclonal lymphoproliferative disorder that manifests as marked hyper-γ-globulinemia, severe inflammation, anemia, and thrombocytosis. Recently, Takai et al. reported a new disease concept, TAFRO syndrome, named from thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly. Furthermore, Kojima et al. reported Japanese MCD cases with effusion and thrombocytopenia (Castleman-Kojima disease). Here, we report two cases of MCD associated with marked pleural effusion, ascites, and thrombocytopenia, and discuss the independence of the TAFRO syndrome (Castleman-Kojima disease). Case 1: A 57-year-old woman had fever, anemia, anasarca, and some small cervical lymphadenopathy. Although she had been administered steroid therapy, and full-coverage antibiotics, her general condition, including fever, systemic inflammation, and anasarca, deteriorated steadily. We administered chemotherapy [CHOEP (cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisolone) regimen], but despite a transient improvement, she died due to septic shock. Case 2: A 73-year-old man with a history of aplastic anemia and remission presented with fever, severe inflammation, and anasarca. Prednisolone was administered (15 mg daily), and his hyperinflammation once improved. Nevertheless, his general condition, including pleural effusion and ascites, worsened, and C-reactive protein and interleukin-6 levels showed marked increases. The patient died due to multiorgan failure. Cases of TAFRO syndrome (Castleman-Kojima disease) are still rare. Therefore, it is necessary to conduct multicenter clinical surveys including similar cases, such as ours, to reach a consensus regarding diagnostic criteria, therapeutic strategy, and pathophysiological etiology for this syndrome.