Clinical and serological association of plasma 25-hydroxyvitamin D (25(OH)D) levels in lupus and the short-term effects of oral vitamin D supplementation.

BACKGROUND AND OBJECTIVES: Data on the association of vitamin D levels and clinical phenotype and disease activity in systemic lupus erythematosus (SLE) is controversial. Further, the optimal dose of oral vitamin D supplementation in SLE is not clear. Thus, the present study was designed to determine the association of plasma vitamin D levels with clinical phenotype, disease variables and serology in a large, cohort of SLE from South Asia and to evaluate the short-term effect of two different dosage regimens of oral vitamin D supplementation on disease flares and plasma vitamin D levels. METHODS: This is a two-phase study. Phase I was a cross-sectional analytical study of patients from north (26.85° N) and south India (11.94° N). Plasma 25-hydroxyvitamin-D(25(OH)D) was measured, and its association with demography, serology, disease activity, Galectin-9 and CXCL-10 was analysed. In phase II, patients with SLEDAI-2KG < 10 and on stable immunosuppression were randomised to receive either high dose (weekly 60,000 U*5, followed by 60,000 U monthly) or routine dose (30,000 U monthly) oral vitamin D. Outcomes were assessed at 6 months RESULTS: Phase I included 702 patients with a mean age of 29.46 + 10.7 years. The median plasma vitamin D was 22.83 (13.8-31.8) ng/ml. Deficiency (< 20 ng/ml) was seen in 41.5% of patients. Patients from South India had higher vitamin D levels (27.06 ± 20.21 ng/dl) as compared to North India (17.15 ± 16.07 ng/ml) (p < 0.01). Univariate analyses demonstrated weak negative correlation of vitamin D with SLEDAI2K and positive correlation with age. Galactin-9 had modest correlation with SLEDAI2K but not with vitamin D levels. On multiple linear regression, centre of recruitment (ß = 4.37) and age (ß = 0.18) predicted (p < 0.05) plasma vitamin D levels. In the phase II, 91 randomised to 2 groups completed 6 months. Median change in plasma vitamin D levels was more in high dose (9.5 versus 2.6 ng/ml; p = 0.04). There were 14 SLE flares and six minor adverse events which were equal across both groups. CONCLUSION: Vitamin D deficiency is common in SLE. Geographical location of residence is the major determinant rather than the disease activity. The IFN regulated proteins reflect disease activity independent of vitamin D levels. High-dose oral vitamin D supplementation seems safe and more effective in improving vitamin D levels in SLE. TRIAL REGISTRATION: The second phase of this study was a registered randomised controlled trial CTRI/2019/06/019658 [registered on: 14/06/2019].

Differentiating flare and infection in febrile lupus patients: Derivation and validation of a calculator for resource constrained settings.

Background: Patients with Systemic Lupus Erythematous (SLE) are at an increased risk of infection and it is often difficult to differentiate between infection and disease activity in a febrile patient with SLE. Methods: Patients with SLE (SLICC criteria) presenting with fever between December 2018 and August 2021 were included. Neutrophil to lymphocyte ratio (NLR), NEUT-x, -y, -z indices, Erythrocyte sedimentation rate (ESR), C-reactive protein(CRP), C3, C4, anti-dsDNA antibodies, and procalcitonin(PCT) were tested in addition to investigations as per the treating physician's discretion. Based on the clinical assessment and laboratory data, the febrile episode was classified into infection, disease flare, or both. Statistical analysis was done using GraphPad prism v8.4.2. A novel composite score was devised and validated with a calculator incorporated is a spreadsheet. The performance of a previously proposed model of duration of fever, CRP, and dsDNA (Beca et al) was evaluated and other models using PCT and NEUT-Z were explored. Results: Among 168 febrile episodes in 166 patients with SLE (25 (19-32) years), 46 were due to infection, 77 due to flare, 43 due to both, and two due to other causes. High SLEDAI 2K (0.001), anti-dsDNA (p = 0.004), and low complements(C3, p = 0.001 and C4, p = 0.001) were characteristic of disease flare, whereas high total leukocyte count (TLC) (p = 0.008), NLR (p = 0.008), NEUT-x (p = 0.001), -y (p = 0.03), -z (p = 0.002), CRP (p = 0.001), and PCT (p = 0.03) were observed with infection. A model using age, TLC, and CRP was devised using 80% of the cohort with an AUC of 0.88 (0.78-0.97) which was validated in the remaining 20% to have an AUC of 0.83(0.60-1.0). The model devised by Beca et al yielded an AUC of 0.74. Use of PCT did not improve the discrimination between flare and infection. A Model of C4 and NEUT-z analyzed in a subset performed well and needs further exploration. Conclusion: A composite score of low cost and routinely available parameters like age, TLC, and CRP gives a good discrimination between infection and flare in a febrile patient with SLE.