Evaluation of the Economic Benefit of Earlier Systemic Lupus Erythematosus (SLE) Diagnosis Using a Multivariate Assay Panel (MAP)

The potential role of serum amyloid A as biomarker of rheumatic diseases: a systematic review and meta-analysis

The identification of novel, robust biomarkers for the diagnosis of rheumatic diseases (RDs) and the presence of active disease might facilitate early treatment and the achievement of favourable long-term outcomes. We conducted a systematic review and meta-analysis of studies investigating the acute phase reactant, serum amyloid A (SAA), in RD patients and healthy controls to appraise its potential as diagnostic biomarker. We searched PubMed, Scopus, and Web of Science from inception to 10 April 2024 for relevant studies. We evaluated the risk of bias and the certainty of evidence using the JBI Critical Appraisal Checklist and GRADE, respectively (PROSPERO registration number: CRD42024537418). In 32 studies selected for analysis, SAA concentrations were significantly higher in RD patients compared to controls (SMD = 1.61, 95% CI 1.24-1.98, p < 0.001) and in RD patients with active disease compared to those in remission (SMD = 2.17, 95% CI 1.21-3.13, p < 0.001). Summary receiving characteristics curve analysis showed a good diagnostic accuracy of SAA for the presence of RDs (area under the curve = 0.81, 95% CI 0.78-0.84). The effect size of the differences in SAA concentrations between RD patients and controls was significantly associated with sex, body mass index, type of RD, and study country. Pending the conduct of prospective studies in different types of RDs, the results of this systematic review and meta-analysis suggest that SAA is a promising biomarker for the diagnosis of RDs and active disease.

From Symptoms to Diagnosis: An Observational Study of the Journey of SLE Patients in Saudi Arabia

Background and Objectives

Early diagnosis and treatment is associated with improved outcomes in patients with systemic lupus erythematosus (SLE). Studying the journey of SLE patients in Saudi Arabia is essential to direct future health-care plans.

Patients and Methods

This is a cross-sectional, multicenter study. Eligibility criteria included a diagnosis of SLE that was confirmed by a rheumatologist. Patients younger than 18 at the time of interview were excluded. Primary objectives were to determine time from first symptoms to initial physician visit (Lag 1), time from initial physician visit to encounter with rheumatologist (Lag 2), time from first visit to a rheumatologist to diagnosis of SLE (Lag 3), and time from diagnosis to start of treatment (Lag 4). Secondary objectives were to determine the number and specialty of physicians seen by patients, the speciality type that confirmed the diagnosis, first symptoms experienced, and age at first diagnosis of SLE.

Results

Three hundred patients (92.3% women) with SLE were evaluated. Mean age at diagnosis was 29.92 years. Mean disease duration was 8.1 years. The majority were college educated (43.0%). The most common initial symptom was joint pain (68%), followed by skin rash (23%), and fever (3.7%). Lag 1 was less than one month in 68.2% of patients. Lag 2 was less than one month in 33.4% of patients and exceeded one year in 25.8%. Lag 3 was less than 1 month in 68.7% of patients. Lag 4 was less than one month in 94.4% of patients. The diagnosis of SLE was made most frequently by rheumatologists (80%). Evaluation by primary care, orthopedic and dermatology physicians were associated with delays in diagnosis.

Conclusion

Delay was marked in Lag 2. Causes of delay included evaluation by non-specialists and visiting higher numbers of physicians before diagnosis confirmation.

Hypocomplementemia in Primary Sjogren's Syndrome: A Retrospective Study of 120 Treatment-Naive Chinese Patients

Objective

To determine the prevalence of hypocomplementemia in primary Sjogren’s syndrome (pSS) patients and compare the clinical characteristics of patients with and without hypocomplementemia.

Methods

A retrospective study was conducted in 120 treatment-naive Chinese patients that met the 2012 American College of Rheumatology Classification Criteria for pSS and were followed up for 3 to 24 months. Based on the complement results, patients were divided into four groups: only low C3, only low C4, both low C3 and C4 (double low), normal group. The data on patient demographics, clinical manifestations, laboratory results, disease activity and pharmacologic therapy were collected and compared among the four groups.

Results

The prevalence of only low C3, only low C4, both low C3 and C4 in pSS patients was 21.7%, 16.7%, and 10%, respectively. The mean age of the four groups was significantly different. Unlike rampant caries and parotitis, the prevalence of dry eyes and dry mouth differed among the four groups. The proportion of patients with anemia, leukocytopenia, lymphadenopathy, hematological involvement and fatigue was significantly higher in the double low group and lower in the normal complement group. The proportion of patients with increased serum IgG was higher in the only low C4 group than in the other groups. Logistic regression revealed that hypocomplementemia was an independent risk factor for lymphadenopathy and leukopenia. The double low group had a significant history of exposure to glucocorticoids and cyclophosphamide, compared with other groups.

Conclusion

Our study found that the clinical characteristics of pSS patients with hypocomplementemia differed from those without hypocomplementemia. Hypocomplementemia in pSS was associated with hematological involvement, hyper-IgG, lymphadenopathy, and fatigue, contributing to more significant exposure to glucocorticoid and cyclophosphamide.

A multianalyte assay panel with cell-bound complement activation products demonstrates clinical utility in systemic lupus erythematosus

Objective

To evaluate the clinical utility of the multianalyte assay panel (MAP), commercially known as AVISE Lupus test (Exagen Inc.), in patients suspected of SLE.

Methods

A systematic review of medical records of ANA-positive patients with a positive (>0.1) or negative (<−0.1) MAP score was conducted when the MAP was ordered (T0), when the test results were reviewed (T1) and at a later time (T2, ≥8 months after T1). Confidence in the diagnosis of SLE and initiation of hydroxychloroquine (HCQ) were assessed.

Results

A total of 161 patient records from 12 centres were reviewed at T0 and T1. T2 occurred for 90 patients. At T0, low, moderate and high confidence in SLE diagnosis was reported for 58%, 30% and 12% patients, respectively. Confidence in SLE diagnosis increased for the MAP positive, while MAP negative made SLE less likely. Odds of higher confidence in SLE diagnosis increased by 1.74-fold for every unit of increase of the MAP score (p<0.001). Using the MAP-negative/anti-double-stranded DNA-negative patients as reference, the HR of assigning an International Classification of Diseases, Tenth Revision lupus code was 7.02-fold, 11.2-fold and 14.8-fold higher in the low tier-2, high tier-2 and tier-1 positive, respectively (p<0.001). The HR of initiating HCQ therapy after T0 was 2.90-fold, 4.22-fold and 3.98-fold higher, respectively (p<0.001).

Conclusion

The MAP helps increase the confidence in ruling-in and ruling-out SLE in patients suspected of the disease and informs on appropriate treatment decisions.