ObjectiveSystemic lupus erythematosus (SLE), an autoimmune disorder, has been associated with nearly 100 susceptibility loci. Nevertheless, these loci only partially explain SLE heritability and their putative causal variants are rarely prioritised, which make challenging to elucidate disease biology. To detect new SLE loci and causal variants, we performed the largest genome-wide meta-analysis for SLE in East Asian populations.MethodsWe newly genotyped 10 029 SLE cases and 180 167 controls and subsequently meta-analysed them jointly with 3348 SLE cases and 14 826 controls from published studies in East Asians. We further applied a Bayesian statistical approach to localise the putative causal variants for SLE associations.ResultsWe identified 113 genetic regions including 46 novel loci at genome-wide significance (p<5×10−8). Conditional analysis detected 233 association signals within these loci, which suggest widespread allelic heterogeneity. We detected genome-wide associations at six new missense variants. Bayesian statistical fine-mapping analysis prioritised the putative causal variants to a small set of variants (95% credible set size ≤10) for 28 association signals. We identified 110 putative causal variants with posterior probabilities ≥0.1 for 57 SLE loci, among which we prioritised 10 most likely putative causal variants (posterior probability ≥0.8). Linkage disequilibrium score regression detected genetic correlations for SLE with albumin/globulin ratio (rg=−0.242) and non-albumin protein (rg=0.238).ConclusionThis study reiterates the power of large-scale genome-wide meta-analysis for novel genetic discovery. These findings shed light on genetic and biological understandings of SLE.

A 15‐year‐old girl developed a haemophagocytic syndrome caused by human parvovirus B19 (PVB19). The cervical lymph node histology, resembling that of histiocytic necrotizing lymphadenitis (HNL, Kikuchi’s disease), included several transformed lymphocytes, numerous histiocytes, and massive necrosis. We detected PVB19‐positive cells in the lymph node by immunohistochemistry. Possible autoimmune mechanisms in HNL‐like diseases triggered by PVB19 are discussed.

IntroductionPatients with rheumatoid arthritis (RA) treated with abatacept (ABT) are at increased risk for vaccine-preventable infections. The aim of the present study is to evaluate the humoral response to 23-valent pneumococcal polysaccharide (PPSV23) vaccination in RA patients receiving ABT.MethodsThe immunogenicity study was nested within a randomized, double-blind placebo-controlled study, designed to evaluate the efficacy of the PPSV23. PPSV23 was given to 111 RA patients, who were classified into three groups: RA control (n = 35), methotrexate (MTX) alone (n = 55), and ABT (n = 21). Before and 4–6 weeks after vaccination, we measured the patients’ concentrations of antibodies against pneumococcal serotypes 6B and 23F using an enzyme-linked immunosorbent assay and determined their antibody functionality using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI).ResultsThe pneumococcal serotype-specific IgG concentrations and OIs were both significantly increased in all treatment groups in response to PPSV23 vaccination. In the ABT group, the IgG responses for the 6B serotype were lower compared with those in the MTX alone or control groups, whereas the OI responses were similar to those in the other two groups. In a subgroup analysis, the pneumococcal serotype-specific IgG responses were significantly lower in both serotypes (6B and 23F) in the ABT/MTX group; however, the OI responses in the ABT group were not different from the control group. There was no association between the pneumococcal serotype-specific IgG and OI responses for the 6B serotype in patients receiving ABT in contrast to the control or MTX alone patients. No severe adverse effects were observed in any of the treatment groups.ConclusionsOI responses indicate antibody functionality rather than simply their amount, so the similarity of these measurements between all three groups suggests that RA patients receiving ABT still benefit from receiving the PPSV23 vaccination, even though they produce less IgG in response to it. The results suggest an influence of ABT on the humoral response to PPSV23 vaccination under MTX treatment; however, preserved opsonin responses are expected in RA patients treated with ABT plus MTX.Trial registrationUniversity Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

IntroductionIn rheumatoid arthritis (RA) patients receiving immunosuppressive treatments, vaccination against Streptococcus pneumoniae is recommended. The objective of the study was to evaluate the effects of tacrolimus (TAC) on immune response following administration of a 23-valent pneumococcal polysaccharide vaccine (PPSV23) in patients with established RA.MethodsPatients with RA (n = 133) were vaccinated with PPSV23. Patients were classified into TAC (n = 29), methotrexate (MTX) (n = 55), control (n = 35), and TAC/MTX (n = 14) treatment groups. We measured the concentrations of pneumococcal serotypes 6B and 23F by using an enzyme-linked immunosorbent assay and determined antibody functionality by using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI), before and 4 to 6 weeks after vaccination. A positive antibody response was defined as at least a twofold increase in the IgG concentration or as at least a 10-fold increase in the OI.ResultsIgG concentrations and OIs were significantly increased in all treatment groups after PPSV23 vaccination. The TAC treatment group appears to respond in a manner similar to that of the RA control group in terms of 6B and 23F serotype concentration and function. In contrast, the MTX group had the lowest immune response. Patients who received a combination of TAC and MTX (TAC/MTX) also had a diminished immune response compared with those who received TAC alone.ConclusionsTAC monotherapy does not appear to impair PPSV23 immunogenicity in patients with RA, whereas antibody production and function may be reduced when TAC is used with MTX. Thus, PPSV23 administration during ongoing TAC treatment should be encouraged for infection-prone TAC-treated patients with rheumatic diseases.Trial registrationUniversity Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-015-0662-x) contains supplementary material, which is available to authorized users.

Background/AimsThe Japanese National Hospital Organization evidence-based medicine (EBM) Study group for Adverse effects of Corticosteroid therapy (J-NHOSAC) is a Japanese hospital-based cohort study investigating the safety of the initial use of glucocorticoids (GCs) in patients with newly diagnosed autoimmune diseases. Using the J-NHOSAC registry, the purpose of this observational study is to analyse the rates, characteristics and associated risk factors of intracellular infections in patients with newly diagnosed autoimmune diseases who were initially treated with GCs.Methodology/Principal FindingsA total 604 patients with newly diagnosed autoimmune diseases treated with GCs were enrolled in this registry between April 2007 and March 2009. Cox proportional-hazards regression was used to determine independent risk factors for serious intracellular infections with covariates including sex, age, co-morbidity, laboratory data, use of immunosuppressants and dose of GCs. Survival was analysed according to the Kaplan-Meier method and was assessed by the log-rank test. There were 127 serious infections, including 43 intracellular infections, during 1105.8 patient-years of follow-up. The 43 serious intracellular infections resulted in 8 deaths. After adjustment for covariates, diabetes (Odds ratio [OR]: 2.5, 95% confidence interval [95% CI] 1.1–5.9), lymphocytopenia (≦1000/μl, OR: 2.5, 95% CI 1.2–5.2) and use of high-dose (≧30 mg/day) GCs (OR: 2.4, 95% CI 1.1–5.3) increased the risk of intracellular infections. Survival curves showed lower intracellular infection-free survival rate in patients with diabetes, lymphocytopaenia and high-dose GCs treatments.Conclusions/SignificancePatients with newly diagnosed autoimmune diseases were at high risk of developing intracellular infection during initial treatment with GCs. Our findings provide background data on the risk of intracellular infections of patients with autoimmune diseases. Clinicians showed remain vigilant for intracellular infections in patients with autoimmune diseases who are treated with GCs.