Decreased HLA (human leucocyte antigen)-DR expression on peripheral blood monocytes predicts the development of organ failure in patients with acute pancreatitis.

Immune suppression plays an important role in the pathogenesis of acute pancreatitis. Monocyte expression of HLA (human leucocyte antigen)-DR, a cellular marker of immune suppression, was determined in relation to the development of organ dysfunction in patients with acute pancreatitis. A total of 310 consecutive patients with acute pancreatitis, admitted to a university hospital within 72 h of pain onset, were studied; 194 (63%) had mild disease (group I), 87 (28%) had severe disease without organ dysfunction (group II), and 29 (9%) had severe disease with organ dysfunction (group III). HLA-DR expression, defined both as the proportion of monocytes that were HLA-DR-positive and as monocyte HLA-DR fluorescence intensity, was determined at admission, using whole-blood flow cytometry. Of the patients in group III, 13 (45%) developed organ dysfunction within 24 h of admission. The proportion of HLA-DR-positive monocytes and monocyte HLA-DR density were both related to the severity of pancreatitis (P<0.001 for linear trend). In predicting organ dysfunction, the sensitivity, specificity and positive-likelihood ratio for the proportion of HLA-DR-positive monocytes were 83% [95% CI (confidence interval) 64-94%], 72% (67-77%) and 3.0 respectively, and for monocyte HLA-DR density the respective values were 69% (49-85%), 84% (79-88%) and 4.3. In conclusion, monocyte HLA-DR expression predicts the development of organ dysfunction that occurs early in patients with acute pancreatitis.