Background/Purpose: SLE diagnostic criteria are important for reliable epidemiologic data. The prevalence of SLE in West Africa is falsely low due to barriers including limited access to both resource and labor-intensive diagnostic testing.  Recently, the ACR and EULAR have proposed a weighted classification tool which is thought to improve diagnostic sensitivity and specificity compared to the established ACR and SLICC criteria. Here we aim to investigate the performance of each classification criteria in two West African cohorts–Korle bu Teaching Hospital, Accra Ghana (GH); and Lagos University Teaching Hospital, Lagos, Nigeria (N)–compared to an NYU Langone-African American (AA) cohort.

Methods: We collected data on a total of 355 SLE patients: AA: n=151, GH: n=110, and N: n=94, diagnosed by expert clinicians. Clinical information including demographics, SLE criteria, SLEDAI scores, SLICC damage indexes, vital signs, and laboratory values as available was obtained at the initial patient encounter. Longitudinal data was collected over the course of at least 1 year at 6 month intervals during routine clinical visits. Where necessary, clinical charts were retrospectively reviewed, and the proportion of patients in each cohort meeting ACR, SLICC and the ACR/EULAR classification criteria was calculated.

Results: The demographics per cohort were as follows: Age (in yrs): AA=43.1, GH=32.4yrs, N=35.5; percent female: AA=90, GH=100, N=97; Mean SLE disease duration (yrs): AA=14.3, GH=2.2, N=4.4. In each cohort, the percentage of patients meeting ACR, SLICC, and ACR/EULAR criteria were AA=96%, 96%, and 95%; GH=85%, 84%, 62%; N=90%, 87%, 61%. This discrepancy was largely due to missing laboratory data particularly with regard to immunologic and hematologic studies. ANA was missing in 0% of the AA cohort, 26% of the GH cohort, and 33% of the N cohort respectively. Compared to the GH and N cohorts, the reference AA cohort was more likely to meet ACR, SLICC, and ACR/EULAR criteria with likelihood ratios (LR) of GH=10.2 p< 0.001 and N=3.0 p=0.08; GH=11.5, p< 0.001 and N=6.3, p=0.01;  and GH=46.1 P< 0.001 and N=44.9, p< 0.001 respectively. On average, the mean number of ACR/EULAR points by cohort was AA: 26.1±11.8, GH: 21.3±8.1, and N: 19.0±6.2. While the ANA entry criteria greatly diminished the new ACR/EULAR diagnostic utility in the GH and N cohorts, the weighted point system performed better than either of the ACR or SLICC criteria with 96% of the AA cohort, 92%of the GH, and 95% of the N cohort meeting criteria (LR: AA vs GH=1.9, p=0.2; AA vs N=0.23, p=0.6).

Conclusion: Due to a relative lack of resources, supportive laboratory assays including an ANA may be more difficult to attain in developing nations. SLE is a clinical syndrome that may be efficiently diagnosed using the new weighted ACR/EULAR criteria. The entry criteria of ANA 1:80 greatly diminished the diagnostic utility of this classification system in the Ghanaian and Nigerian cohorts compared to the African American cohort. Clinical trials should consider offering wide ANA testing to cohorts in the developing world.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/a-tale-of-three-cohorts-sle-criteria-in-developed-vs-developing-countries/