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Case Control Study
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World J Nephrol. Jun 25, 2026; 15(2): 116866
Published online Jun 25, 2026. doi: 10.5527/wjn.v15.i2.116866
Alpha-1-microglobulin as an early biomarker in renal extrahepatic manifestations of hepatitis C virus infection
Enas A R Alkareemy, Nashwa M Azoz, Ghada S Abdelnaiem, Rabea A Gadelkareem, Kawsar A Saleh, Essam M Abdel Aziz
Enas A R Alkareemy, Department of Internal Medicine-Gastroenterology and Hepatology, Assiut University Hospital, Faculty of Medicine, Assiut University, Assiut 71711, Egypt
Nashwa M Azoz, Ghada S Abdelnaiem, Essam M Abdel Aziz, Department of Internal Medicine-Nephrology, Assiut University Hospital, Faculty of Medicine, Assiut University, Assiut 71711, Egypt
Rabea A Gadelkareem, Department of Urology, Assiut Urology and Nephrology Hospital, Faculty of Medicine, Assiut University, Assiut 71711, Egypt
Kawsar A Saleh, Department of Diagnostic and Interventional Radiology, Assiut University Hospital, Faculty of Medicine, Assiut University, Assiut 71711, Egypt
Author contributions: Alkareemy EAR, Gadelkareem RA, Saleh KA, and Abdel Aziz EM contributed to literature review, writing, and revision; Alkareemy EAR and Gadelkareem RA supervision of the work; Azoz NM and Abdelnaiem GS designed the research, collected the data, and wrote the paper; Saleh KA and Abdel Aziz EM contributed to statistical analysis. All authors approved the final paper.
Institutional review board statement: This study was approved by the Ethics Committee of the Faculty of Medicine of Assiut University (Approval No. 17200739).
Informed consent statement: Written informed consent was obtained from patients for participation in the study.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Data sharing statement: The data supporting this study are available from the corresponding author on reasonable request.
Corresponding author: Rabea A Gadelkareem, MD, Department of Internal Medicine-Gastroenterology and Hepatology, Assiut University Hospital, Faculty of Medicine, Assiut University, Elgamaa Street, Assiut 71711, Egypt. rabeagad@aun.edu.eg
Received: November 24, 2025
Revised: December 21, 2025
Accepted: February 3, 2026
Published online: June 25, 2026
Processing time: 202 Days and 22.6 Hours
Abstract
BACKGROUND

Hepatitis C virus (HCV)-related nephropathy often progresses silently and is commonly underrecognized until chronic kidney disease or acute kidney injury occurs. Urinary alpha-1-microglobulin (Uα1M) is a promising early biomarker of proximal tubule dysfunction. It may help detect the subclinical renal extrahepatic manifestations of HCV earlier than traditional markers such as serum creatinine (SCr). The early renal manifestations of HCV include microalbuminuria, hematuria, tubular injury, and immune-mediated glomerulopathy.

AIM

To evaluate the efficacy of Uα1M in identifying the early kidney involvement in patients with HCV infection.

METHODS

A case-control study was conducted from February 2022 to February 2024 at the Clinic of Nephrology Outpatient, Department of Internal Medicine, and Clinic of El-Rajhy Hepatitis Outpatient at Assiut University Hospitals. This study involved 158 patients aged ≥ 18 years, divided into HCV and control groups. The HCV group included 79 patients diagnosed as HCV-positive by HCV + antibodies and positive real-time polymerase chain reaction for HCV-RNA. The control group included 79 participants who were age-matched and sex-matched, and HCV-negative healthy individuals. The primary outcome was the rate of increased level of Uα1M.

RESULTS

The two groups were comparable in age and sex distribution. The mean hemoglobin level and platelet count were significantly lower in HCV patients than in controls, respectively. Blood urea nitrogen (BUN), SCr, and estimated glomerular filtration rate (eGFR) showed no significant differences. The urinary albumin/creatinine ratio was significantly higher in HCV-positive patients, with increased prevalence of microalbuminuria and macroalbuminuria. Uα1M levels were markedly elevated in the HCV group. It correlated positively with BUN and SCr, and negatively with eGFR, aspartate aminotransferase, and alanine aminotransferase. Uα1M levels were significantly higher in patients with hematuria (P = 0.007) and those with impaired eGFR (P < 0.001) than those without these disorders. Only five HCV-positive patients underwent renal biopsy, and all showed membranoproliferative glomerulonephritis. The Uα1M levels higher than the 3.52 mg/L cutoff had strong diagnostic ability to distinguish HCV-positive from HCV-negative subjects, with an area under the curve of 0.864 (95% confidence interval: 0.801-0.913), 77.0% accuracy, 60.0% sensitivity, 93.7% specificity, 90.4% positive predictive value, and 69.8% negative predictive value (P < 0.001).

CONCLUSION

Uα1M served as a valuable early renal tubular biomarker for detecting subclinical kidney involvement in chronic HCV patients. It showed a moderate correlation to BUN and mild correlation to SCr and eGFR, with membranoproliferative glomerulonephritis pathology predominance in biopsied cases. In addition, it had a strong diagnostic accuracy at levels higher than a cutoff of 3.52 mg/L, reinforcing its potential for early diagnosis of renal involvement by HCV infection.

Keywords: Alpha-1-microglobulin; Hepatitis C virus; Kidney injury; Renal extrahepatic manifestations; Urinary biomarkers

Core Tip: Chronic hepatitis C virus (HCV) infection can lead to subclinical renal injury that often progresses unnoticed until chronic kidney disease develops. In this study, urinary alpha-1-microglobulin (Uα1M) proved to be a sensitive, early, and non-invasive biomarker for detecting tubular dysfunction in HCV-infected patients. The rate of elevated Uα1M levels correlated with subtle renal alterations and demonstrated strong diagnostic accuracy, even when traditional renal markers were within normal limits. Routine Uα1M assessment may facilitate early detection and intervention for HCV-related renal involvement, improving long-term renal outcomes.

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