Renal injury, biomarkers, and myositis, an understudied aspect of disease: prospective study in the MyoCite cohort

Edoardo Conticini; R Naveen; Parikshit Sen; Mantabya Singh; Upendra Rathore; Anamika Kumari Anuja; Mohit Kumar Rai; Brijesh Yadav; Narayan Prasad; Vikas Agarwal; Latika Gupta

doi:10.3389/fmed.2023.1127657

Renal injury, biomarkers, and myositis, an understudied aspect of disease: prospective study in the MyoCite cohort

Front Med (Lausanne). 2023 Jun 22:10:1127657. doi: 10.3389/fmed.2023.1127657. eCollection 2023.

Authors

Affiliations

¹ Rheumatology Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy.
² Department of Clinical Immunology and Rheumatology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
³ Maulana Azad Medical College, New Delhi, India.
⁴ Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
⁵ Department of Rheumatology, Royal Wolverhampton Hospitals NHS Trust, Wolverhampton, United Kingdom.
⁶ Division of Musculoskeletal and Dermatological Sciences, Centre for Musculoskeletal Research, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom.
⁷ Department of Rheumatology, City Hospital, Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, United Kingdom.

Abstract

Introduction: The mechanisms leading to chronic kidney disease (CKD) in patients with idiopathic inflammatory myopathies (IIMs) are poorly understood. We assessed the prevalence of subclinical renal injury in patients with IIMs, through elevation in biomarker levels of tubular injury and fibrosis (NGAL, KIM1, Activin A, CD163, and Cys-c), and assessed differences between subtypes of IIMs, and the effect of disease activity and duration.

Materials and methods: Clinical data, core set measures, sera and urine were prospectively collected from all patients enrolled in the MyoCite cohort from 2017 to 2021. Twenty healthy subjects (HC) and 16 patients with acute kidney injury (AKI) were included as controls. Baseline and follow up data for IIMs were included. Enzyme-linked immunosorbent assay (ELISA) was used to measure urine NGAL (Human Lipocalin-2/NGAL Duoset ELISA, Cat no: DY1757), KIM1 (Human TIM-1/KIM 1/HAVCR Duoset ELISA, Cat.no: DY1750B), Activin A (Human Activin A Duoset ELISA, Cat no: DY338), CD163 (Human CD163 Duoset ELISA,Cat no: DY1607-05), and Cys-c (Human Cystatin C Duoset ELISA, Cat. no.: DY1196) levels, while eGFR (unit mL/min/1.73 m2) was calculated by the Cockcroft-Gault formula and CKD-EPI formula.

Results: Analysis of 201 visits of 110 adult patients with IIMs indicated higher normalized biomarker levels compared to HCs, and comparable to patients with AKI, with the exception of NGAL, which was higher in the AKI group. Notably 72 (49%) patients with IIMs had eGFR<90; the levels of the 5 biomarkers were comparable between active and inactive IIMs, and different subtypes of IIMs. Similarly, a poor correlation between urine biomarker levels and core set measures of activity and damage was found. Changes in biomarker levels on follow-up did not correlate with eGFR changes.

Discussion: This exploratory analysis of urinary biomarkers identified low eGFR and elevated biomarkers of CKD in nearly half of the patients with IIMs, comparable to patients with AKI and higher than HCs, indicative of potential renal damage in IIMs that may have a lead to complications in other systems.

Keywords: India; biomarker; damage; myositis; renal.