Serum Concentrations of Ischaemia-Modified Albumin in Acute Coronary Syndrome: A Systematic Review and Meta-Analysis

Ischemia-modified albumin in rheumatic diseases: A systematic review and meta-analysis

INTRODUCTION

The identification of novel, easily measurable disease biomarkers might enhance the diagnosis and management of patients with rheumatic diseases (RDs). We conducted a systematic review and meta-analysis of ischemia-modified albumin (IMA), a marker of oxidative stress, acidosis, and ischemia, in RD patients and healthy controls.

METHODS

We searched PubMed, Web of Science, and Scopus from inception to January 15, 2024. The risk of bias and the certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and GRADE, respectively.

RESULTS

In 20 studies investigating a total of 1188 RD patients (mean age 45 years, 64% females) and 981 healthy controls (mean age 44 years, 66% females), RD patients had significantly higher IMA concentrations when compared to controls (standard mean difference, SMD = 0.50, 95% CI: 0.18-0.83, p = .003; I2 = 92.4%, p < .001; low certainty of evidence). In subgroup analysis, the pooled SMD was significantly different in studies investigating ankylosing spondylitis (p < .001), Behçet's disease (p < .001), and rheumatoid arthritis (p = .033), but not familial Mediterranean fever (p = .48). Further associations were observed between the pooled SMD and the broad classification of autoimmune and/or autoinflammatory diseases, the study country, and the method used to measure IMA.

CONCLUSION

Our study suggests that IMA is a promising biomarker of oxidative stress, acidosis, and ischemia, as it can effectively discriminate between patients with different types of RDs and healthy controls. Our results warrant confirmation in longitudinal studies of patients with different types of RDs and different ethnicities (PROSPERO registration number: CRD42024509126).

Association between ischemia-modified albumin (IMA) and peripheral endothelial dysfunction in rheumatoid arthritis patients

The identification of circulating biomarkers of endothelial dysfunction (ED), a precursor to atherosclerosis, in rheumatoid arthritis (RA) would facilitate early risk stratification and prevention strategies. Ischemia-modified albumin (IMA) has emerged as a potential biomarker of oxidative stress, ischemia, and ED. However, studies examining the relationship between IMA and ED in RA patients are lacking. We measured serum IMA concentrations by using an albumin cobalt binding test and peripheral vasodilatory capacity by EndoPAT in 113 RA patients without previous cardiovascular events enrolled in the EDRA study (ClinicalTrials.gov: NCT02341066). The mean peripheral vasodilatory capacity, expressed by the log of reactive hyperemia index (logRHI), was 0.82, corresponding to 27% RA patients having ED. The mean plasma concentrations of IMA were 0.478 absorbance units. We observed a significant and inverse association between peripheral vasodilatory capacity and serum IMA concentrations (rho =  - 0.22, p = 0.02). In univariate logistic regression, ED was significantly associated with serum IMA concentrations [OR 1173 (95% CI 1.3568 to 101,364), p = 0.040) and higher disease activity. In multivariate logistic regression, the independent association between ED and IMA remained significant after correction for disease activity and other RA-confounders [OR 2252 (95% CI 1.0596 to 4,787,505), p = 0.048 in Model 1; OR 7221 (95% CI 4.1539 to 12,552,859), p = 0.02 in Model 2]. Conclusions: This study suggests that IMA is a promising biomarker of ED in RA. Further research is needed to confirm our findings and determine the clinical utility of IMA in detecting and managing early atherosclerosis in RA patients.

Association of Ischemia-Modified Albumin (IMA) in Saliva, Serum, and Urine with Diagnosis of Chronic Kidney Disease (CKD) in Children: A Case-Control Study

BACKGROUND Ischemia-modified albumin (IMA) is a secreted biomarker for ischemic oxidative stress. This case-control study aimed to evaluate the association of ischemia-modified albumin (IMA) in saliva, serum, and urine with diagnosis of chronic kidney disease (CKD) in 24 children. MATERIAL AND METHODS The study involved 24 children with CKD. CKD was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) diagnostic criteria. The control group consisted of 24 healthy children who were matched for age and gender to the experimental group. The concentration of IMA was determined by the colorimetric method in non-stimulated whole saliva (NWS), stimulated whole saliva (SWS), serum, and urine of children with CKD. The Mann-Whitney U test was used for inter-group comparisons. RESULTS IMA levels were significantly higher in NWS (P=0.0082) and SWS (P=0.0014) of children with CKD than in the control group. The concentration of IMA in NWS was correlated with standard indicators of kidney function, including the estimated glomerular filtration rate (r=-0.798, P≤0.0001), stage of CKD (r=0.814, P≤0.0001), and serum creatinine (r=0.711, P≤0.0001) and urea levels (r=0.738, P≤0.0001). CONCLUSIONS Salivary IMA concentration depends on renal function in children. Salivary IMA discriminates children with end-stage kidney disease from children with mild and moderate CKD and healthy children with high sensitivity and specificity. Further research is required, including assessment of the diagnostic usefulness and validation of the biomarker in a clinical diagnostic study.