Introduction: Proteinuria is a common finding in acute pancreatitis (AP). Increased urinary beta 2-microglobulin can be explained by renal tubular malfunction induced by substances released from the pancreas. The degree of renal tubular malfunction may reflect the severity of AP.
Aim: To assess proteinuria and urinary beta 2-microglobulin as prognostic factors in AP.
Patients and methods: We retrospectively studied patients with AP with symptom onset within 24 hours before admission. Random urine specimens were obtained on days 1, 2 and 3 after admission. In a subgroup of 25 patients, urine samples could be obtained within 24 hours of symptom onset on day 1. The severity of AP was established using the Atlanta criteria. Proteinuria and beta 2-microglobulin were determined and were adjusted by urinary creatinine concentrations.
Results: We studied 51 patients with AP (26 men and 25 women; age: 59.6 (+/-16.7 years). Fifteen cases of AP were severe and 36 were mild. The most frequent etiology was gallstones (60.1%). Levels of proteinuria were (median and interquartile range) in mg/g creatinine: day 1: 180.5 (84.0-250.9), day 2: 164.3 (16.7-421.7), and day 3: 136.7 (24.0-371.29). Differences between severe and mild AP were significant on day 2 of admission: 339.7 (191.7-471.8) versus 120,1 (11.0-382.6); p = 0.04. Levels of urinary beta 2-microglobulin in AP on days 1 to 3 postadmission were: 9.7 (1.1-93.3), 27.6 (4.7-421.4) and 88.3 (7.3-415.2) microg/mg of creatinine, respectively. When urinary beta 2-microglobulin was compared between severe and mild AP, no significant differences were found among days 1, 2 and 3. Selection of only the subgroup of patients whose urine samples were obtained within 24 h of symptom onset, did not improve the results of these urine markers for the group as a whole.
Conclusions: 1) Proteinuria was slightly increased in severe AP and was able to discriminate between mild and severe episodes on day 2 of admission. 2) Urinary beta 2-microglobulin as a tubular malfunction marker did not discriminate between mild and severe AP in patients in our study.