Harley, John B.

Abstract Processes that lead to clinical illness in SLE years before diagnosis are not well characterized. This study evaluates the temporal relationship between autoantibody production, cytokine levels and the onset of SLE. Serial sera from 60 SLE cases before diagnosis with no ACR criteria to SLE classification (average timespan=4.4 years) and matched healthy controls (HC) were obtained from the DODSR. Sera samples were tested for autoantibodies (BioPlex2200), C-reactive protein (hs-CRP), Von Willebrand’s Factor (VWF) and 32 soluble inflammatory mediators, including cytokines, chemokines, and soluble receptors. Patient samples before ACR classification had significant (p < 0.01) alterations in 16 soluble mediators of inflammation, as well as VWF and hs-CRP. TNF Receptor levels, TNFRI, TNFRII, BLyS, and APRIL, dramatically increased as lupus classification approached (p < 0.001). The increase in TNFR shedding parallels the accumulation of autoantibodies in SLE cases. Interferon (IFN)-associated mediators of inflammation, IFN-γ, IP-10, MIG, and MIP-1α (p < 0.01), were also increased leading up to classification. That these alterations are present prior to the transition to active SLE suggests that multiple perturbations in immune-mediated inflammatory processes occur long before clinical classification and suggest that high-risk, pre-clinical individuals, can be identified before their illness is clinically manifested and damage occurs.

Abstract The human eosinophil granule contains a number of cationic proteins that have been identified and purified to homogeneity, including the major basic protein (MBP), the eosinophil cationic protein (ECP), and the eosinophil-derived neurotoxin (EDN). Because of confusion in the literature regarding the distinctiveness of MBP and ECP, we investigated the immunochemical and physicochemical properties of these purified proteins by electrophoresis on sodium dodecyl sulfate-polyacrylamide gels (SDS-PAGE), by specific double antibody radioimmunoassays (RIA) for MBP and ECP, and by fractionation of acid-solubilized eosinophil granules on Sephadex G-50 columns. Analysis of a mixture of the three purified proteins by SDS-PAGE showed that they migrated as three distinct bands with differing m.w. Comparison by specific RIA for MBP and ECP did not demonstrate any appreciable immunochemical cross-reactivities among the three proteins. Sephadex G-50 column fractions of acid-solubilized eosinophil granules were analyzed by RIA and by SDS-PAGE analysis of individual column fractions. MBP, ECP, and EDN eluted at different volumes from Sephadex G-50 columns as determined by RIA and SDS-PAGE. Soluble extracts of eosinophil granules from patients with the hypereosinophilic syndrome contained between six and 64 times more MBP than ECP on a weight basis. These observations demonstrate that MBP, ECP, and EDN are distinctive cationic proteins of the human eosinophil granule and that eosinophil granules from patients with eosinophilia contain considerably greater quantities of MBP than ECP.

ObjectiveSystemic lupus erythematosus (SLE) and other autoimmune diseases cause significant morbidity. Identifying populations at risk of developing SLE is essential for curtailing irreversible inflammatory damage. The aim of this study was to identify factors associated with transition to classified disease that would inform our understanding of the risk of SLE.MethodsPreviously identified blood relatives of patients with SLE, who had <4 American College of Rheumatology (ACR) classification criteria for SLE at baseline, were enrolled in this follow‐up study (n = 409 unaffected relatives). Participants provided detailed family, demographic, and clinical information, including the SLE‐specific portion of the Connective Tissue Disease Screening Questionnaire (SLE‐CSQ). Serum and plasma samples were tested for the presence of lupus‐associated autoantibodies and 52 soluble mediators. Generalized estimating equations (GEEs) were applied to identify factors predictive of disease transition.ResultsOf the 409 unaffected relatives of SLE patients, 45 (11%) had transitioned to classified SLE at follow‐up (mean time to follow‐up 6.4 years). Relatives who transitioned to SLE displayed more lupus‐associated autoantibody specificities and higher SLE‐CSQ scores (P < 0.0001) at baseline than did relatives who did not transition. Importantly, those who had developed SLE during the follow‐up period also had elevated baseline plasma levels of inflammatory mediators, including B lymphocyte stimulator, stem cell factor (SCF), and interferon‐associated chemokines (P ≤ 0.02), with concurrent decreases in the levels of regulatory mediators, transforming growth factor β (TGFβ), and interleukin‐10 (P ≤ 0.03). GEE analyses revealed that baseline SLE‐CSQ scores or ACR scores (number of ACR criteria satisfied) and plasma levels of SCF and TGFβ, but not autoantibodies, were significant and independent predictors of SLE transition (P ≤ 0.03).ConclusionPreclinical alterations in levels of soluble mediators may predict transition to classified disease in relatives of SLE patients. Thus, immune perturbations precede SLE classification and can help identify high‐risk relatives for rheumatology referral and potential enrollment in prevention trials.

Objective Lupus nephritis (LN) is a severe manifestation of systemic lupus erythematosus (SLE) that exhibits familial aggregation and may progress to end‐stage renal disease (ESRD). LN is more prevalent among African Americans than among European Americans. This study was undertaken to investigate the hypothesis that the apolipoprotein L1 gene ( APOL1 ) nephropathy risk alleles G1/G2, common in African Americans and rare in European Americans, contribute to the ethnic disparity in risk. Methods APOL1 G1 and G2 nephropathy alleles were genotyped in 855 African American SLE patients with LN‐ESRD (cases) and 534 African American SLE patients without nephropathy (controls) and tested for association under a recessive genetic model, by logistic regression. Results Ninety percent of the SLE patients were female. The mean ± SD age at SLE diagnosis was significantly lower in LN‐ESRD cases than in SLE non‐nephropathy controls (27.3 ± 10.9 years versus 39.5 ± 12.2 years). The mean ± SD time from SLE diagnosis to development of LN‐ESRD in cases was 7.3 ± 7.2 years. The G1/G2 risk alleles were strongly associated with SLE‐ESRD, with 25% of cases and 12% of controls having 2 nephropathy alleles (odds ratio [OR] 2.57, recessive model P = 1.49 × 10 −9 ), and after adjustment for age, sex, and ancestry admixture (OR 2.72, P = 6.23 × 10 −6 ). The age‐, sex‐, and admixture‐adjusted population attributable risk for ESRD among patients with G1/G2 polymorphisms was 0.26, compared to 0.003 among European American patients. The mean time from SLE diagnosis to ESRD development was ∼2 years earlier among individuals with APOL1 risk genotypes ( P = 0.01). Conclusion APOL1 G1/G2 alleles strongly impact the risk of LN‐ESRD in African Americans, as well as the time to progression to ESRD. The high frequency of these alleles in African Americans with near absence in European Americans explains an important proportion of the increased risk of LN‐ESRD in African Americans.

Systemic lupus erythematosus (SLE) patients frequently have high circulating tumor necrosis factor alpha (TNF-α) levels. We explored circulating TNF-αlevels in SLE families to determine whether high levels of TNF-αwere clustered in a heritable pattern. We measured TNF-αin 242 SLE patients, 361 unaffected family members, 23 unaffected spouses of SLE patients, and 62 unrelated healthy controls. Familial correlations and relative recurrence risk rates for the high TNF-αtrait were assessed. SLE-affected individuals had the highest TNF-αlevels, and TNF-αwas significantly higher in unaffected first degree relatives than healthy unrelated subjects(P=0.0025). No Mendelian patterns were observed, but 28.4% of unaffected first degree relatives of SLE patients had high TNF-αlevels, resulting in a first degree relative recurrence risk of 4.48(P=2.9×10-5). Interestingly, the median TNF-αvalue in spouses was similar to that of the first degree relatives. Concordance of the TNF-αtrait (high versus low) in SLE patients and their spouses was strikingly high at 78.2%. These data support a role for TNF-αin SLE pathogenesis, and TNF-αlevels may relate with heritable factors. The high degree of concordance in SLE patients and their spouses suggests that environmental factors may also play a role in the observed familial aggregation.