Early prediction of severe acute pancreatitis by urinary β-2 microglobulin/saposin B peak ratios on MALDI-TOF

• Ratio of urinary B2M to SB on MALDI-TOF can be used to predict severe AP.
• The best cut-off B2M/SB ratio is 1.127 with a sensitivity of 83.7% and a specificity of 74.3%.
• Quantitative proteomics indicated that severe AP is accompanied with kidney injury/inflammation.

The current methods for predicting severe acute pancreatitis (severe AP) are either complicated or lack efficient sensitivity and specificity. In this study, a simple and practical approach was developed to predict severe AP by using peak intensity ratio of urinary β-2 microglobulin (B2M) to saposin B (SB) on MALDI-TOF MS. Patients with B2M/SB ratio higher than 1.127 present severe AP symptom with a higher Ranson score, computed tomography (CT) grade and longer hospitalization with a sensitivity of 83.7% and specificity of 74.3%. Label-free quantitative proteomics by nanoLC–MS/MS was applied to urine of severe AP patients and found that severe AP is accompanied with kidney injury and inflammation. The measurement of B2M/SB ratios by MALDI-TOF MS could be a simple, accurate and rapid method to diagnose severe AP as well as to monitor AP progression.