Faculty Bibliography

Approximately 40% of patients who survive acute episodes of thrombotic thrombocytopenic purpura (TTP) associated with severe acquired ADAMTS13 deficiency experience one or more relapses. Risk factors for relapse other than severe ADAMTS13 deficiency and ADAMTS13 autoantibodies are unknown. ADAMTS13 autoantibodies, TTP episodes following infection or type I interferon treatment and reported ensuing systemic lupus erythematosus in some patients suggest immune dysregulation. This cross-sectional study asked whether autoantibodies against RNA-binding proteins or peripheral blood gene expression profiles measured during remission are associated with history of prior relapse in acquired ADAMTS13-deficient TTP. Peripheral blood from 38 well-characterized patients with autoimmune ADAMTS13-deficient TTP in remission was examined for autoantibodies and global gene expression. A subset of TTP patients (9 patients, 24%) exhibited a peripheral blood gene signature composed of elevated ribosomal transcripts that associated with prior relapse. A non-overlapping subset of TTP patients (9 patients, 24%) displayed a peripheral blood type I interferon gene signature that associated with autoantibodies to RNA-binding proteins but not with history of relapse. Patients who had relapsed bimodally expressed higher HLA transcript levels independently of ribosomal transcripts. Presence of any one potential risk factor (ribosomal gene signature, elevated HLA-DRB1, elevated HLA-DRB5) associated with relapse (OR = 38.4; p = 0.0002) more closely than any factor alone or all factors together. Levels of immune transcripts typical of natural killer (NK) and T lymphocytes positively correlated with ribosomal gene expression and number of prior episodes but not with time since the most recent episode. Flow cytometry confirmed elevated expression of cell surface markers encoded by these transcripts on T and/or NK cell subsets of patients who had relapsed. These data associate elevated ribosomal and immune transcripts with relapse history in acquired, ADAMTS13-deficient TTP.

Objective. Accurate assessment of lupus flares is critical but problematic in clinical trials. This study examined the impact of modifications to the classic Safety of Estrogens in Lupus Erythematosus National Assessment (SELENA)-SLEDAI flare index (cSFI).Methods. Ninety-one SLE patient records were evaluated at two visits at which the SLEDAI and BILAG had been scored prospectively. The cSFI was compared with an experimental version (eSFI) that eliminated medication criteria and separated the mild/moderate flare category into its components by clinical judgement based on records. The revised SFI (SFI-R) and some physician's global assessments (PGAs) were also scored using chart notes.Results. eSFI-rated moderate flares had higher PGA and BILAG scores than those rated as mild. When medication criteria were excluded, 42 of 55 cSFI severe flares and 15 of 49 mild/moderate flares were downgraded in severity. Comparing flares that remained severe with those that were downgraded, disease activity was higher by PGA (P < 0.001), SLEDAI (P < 0.001), BILAG (P < 0.001), number of active BILAG organs (P < 0.04) and flaring SFI-R organs (P < 0.01). PGA (P < 0.001) and the number of SFI-R domains flaring (P < 0.001) were higher in mild/moderate eSFI flares than in those that were downgraded. Twenty-one of 83 (25%) medication changes occurred with no flare. Forty-six of 52 (88%) medication changes defining severe flare by cSFI involved patients rated by physicians with no, mild or moderate flares.Conclusion. A deconstructed flare index improves the discrimination of mild from moderate flares and selects more ill patients with true clinical worsening for each category of flare.

Objective: Systemic lupus erythematosus (SLE) is a complex and multifactorial autoimmune disease with striking clinical, immunologic and genetic heterogeneity, despite nearly ubiquitous antinuclear antibody (ANA) production. Multiple gene polymorphisms have been associated with the disease, but individually account for only a very small percentage of overall SLE risk. In earlier studies, constitutive expression of the DNA-binding protein, A+T rich interacting domain 3a (ARID3a) in transgenic mouse B lymphocyte lineage cells led to spontaneous ANA production and preferential development of B cells associated with production of polyreactive antibodies. Therefore, we asked if ARID3a was over-expressed in B lymphocytes of SLE patients and if ARID3a expression was associated with disease severity. Methods: A cross section of SLE patients and age and gender-matched controls were analyzed longitudinally for lupus disease activity, numbers of ARID3a+ peripheral blood mononuclear B cells from multiple B cell subsets, immunoglobulin and cytokine levels. Results: Fifty of 115 patients (43%) had dramatically increased numbers of ARID3a+ B cells compared to healthy controls. ARID3a is not expressed in naive B cells of healthy controls, but was abundant in these precursors of antibody-secreting cells in SLE patients. Total numbers of ARID3a+ B cells correlated with increased disease activity as defined by SLE Disease Activity Index scores in individuals assessed at three time points. Conclusion: These findings identify B cell anomalies in SLE that allow stratification of patient samples based on ARID3a expression and implicate ARID3a as a potential marker of CD19+ B lymphocytes correlated with disease activity. (c) 2014 American College of Rheumatology.