Masuyuki Nawata

Possible triggering effect of cytomegalovirus infection on systemic lupus erythematosus.

We report on a patient with systemic lupus erythematosus (SLE) who showed elevated titers of IgM antibodies to cytomegalovirus (CMV), suggesting CMV infection at the onset of SLE. Serum CMV antigens were also detected in the patient. These findings raise the possibility that CMV infection may be related to the onset of SLE in certain patients.We report on a patient with systemic lupus erythematosus (SLE) who showed elevated titers of IgM antibodies to cytomegalovirus (CMV), suggesting CMV infection at the onset of SLE. Serum CMV antigens were also detected in the patient. These findings raise the possibility that CMV infection may be related to the onset of SLE in certain patients.

Two cases of reactive hemophagocytic syndrome: a patient with adult-onset Still's disease and a patient with herpes zoster and autoimmune abnormalities.

Abstract We report two cases of bone marrow hemophagocytosis. One patient had adult-onset Stills disease, and the other had herpes zoster associated with potential autoimmune abnormalities. Our findings suggested a pos-sible role of cytokines and/or antibodies in the induction of hemophagocytosis in patients with connective tissue diseases and/or immune abnormalities.

Anti-proteasome activator 28α is a novel anti-cytoplasmic antibody in patients with systemic lupus erythematosus and Sjögren’s syndrome

We evaluated the extent to which anti-proteasome activator (PA) 28α antibodies act as anti-cytoplasmic antibodies in systemic lupus erythematosus (SLE) and Sjögren’s syndrome (SS). Sera from 46 SLE patients without SS, 11 SLE patients with SS, and 45 primary SS patients were tested. Using anti-PA28α and anti-PA28γ (Ki) antibodies purified from nitrocellulose membranes onto which recombinant PA28α and Ki had been transferred, the cellular distributions of the targeted antigens were analyzed immunohistochemically. In addition, the incidence of anti-PA28α antibodies was compared with those of other anti-cytoplasmic antibodies. Immunofluorescent staining showed that purified anti-PA28α antibodies reacted with the cytoplasm of HEp-2 cells, whereas purified anti-Ki antibodies reacted with nucleoplasm. Among the 15 SLE patients without SS, the six SLE patients with SS, and the 30 primary SS patients who were anti-cytoplasmic-antibody positive, anti-SS-A/Ro antibodies were the most frequently detected (53, 67, and 70%, respectively); anti-PA28α antibodies were, respectively, detected in 33, 50, and 40% of those patient groups, incidences that were higher than those of anti-ribosomal P, anti-smooth muscle and anti-mitochondrial M2 antibodies. These results show that anti-PA28α antibodies are major anti-cytoplasmic antibodies in patients with SLE and SS, and the distinct cellular distributions of PA28α and Ki suggest these proteins are associated with different cellular functions.

Analysis of the Structure of Proteasome‐Proliferating Cell Nuclear Antigen (PCNA) Multiprotein Complex and Its Autoimmune Response in Lupus Patients

We have recently found that the PCNA multiprotein complexes (PCNA complexes) associated with cell proliferation can be purified using monoclonal antibodies (mAbs) to PCNA.1 We attempted to analyze the structure of the complexes and found that proteasome, which had been known as an ATP-dependent proteolytic enzyme involved in antigen presentation on class I major histocompatibility molecules, was one of the elements of the PCNA complex. We also found that there was an autoimmune-response linkage between PCNA and proteasome.

Activated peripheral blood mononuclear cells detected in lupus patients using cDNA coding for proliferating cell nuclear antigen

Abstract The expression of proliferating cell nuclear antigen (PCNA) mRNA in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE) was measured by dot blot hybridization using a PCNA cDNA, and correlated with the percentage of PCNA-positive cells detected immunohistochemically using a monoclonal anti-PCNA antibody. PCNA-positive PBMCs were detected in 72.2% of SLE patients (n = 36), which is significantly more than among healthy controls. In addition, among those in whom PCNA expression was detected, the percentage of PBMCs expressing PCNA was significantly higher in SLE patients (mean 2.5% vs. 0.15%). The level of PCNA mRNA was increased in PBMCs from 83.3% of SLE patients, and was significantly correlated with the percentage of PCNA-positive cells (r = 0.54, P < 0.01) and with the disease activity score (r = 0.56, P < 0.01). A longitudinal study of two SLE patients confirmed that PCNA mRNA expression and the percentages of PCNA-positive cells varied in parallel with disease activity. Thus, an analysis of activated PBMCs from SLE patients using PCNA cDNA may be a useful method by which to estimate SLE disease activity.