B2 microglobulin: Is it a reliable marker of activity in inflammatory bowel disease?

OBJECTIVES: The aims of this study were to investigate a possible positive correlation between B2-microglobulin (B2-M) serum levels and the severity a nd activity of inflammatory bowel disease (IBD); and to examine whether B2- M levels reflect IBD extent. METHODS: We examined B2-M serum levels in 87 ulcerative colitis (UC) patien ts, 74 with Crohn's disease (CD) and 68 control subjects, using an enzymati c method. The reliability of the measuring method was assessed by evaluatin g serum B2-M in 18 patients suffering from chronic renal failure (CRF). The severity and activity of IBD was estimated using the van Hees Activity Ind ex and the True-love-Witts criteria for CD and UC patients respectively. En doscopic evaluation for UC patients was done according to Baron's et nl. cl assification; Riley's et al. criteria were used for histological evaluation . RESULTS: B2-M serum levels were significantly increased in all CD patients except those in remission. After 6 months treatment a second blood sample t aken from CD patients with initially elevated B2-M levels proved to be comp atible with CD severity at that time. Such a positive correlation was not a ssessed in UC patients; therefore, a second blood sample was considered unn ecessary. Furthermore, CD patients with pancolitis, ileal-caecal, or small intestinal disease had higher B2-M levels than those with left-sided, anal, or perianal disease. CONCLUSIONS: B2-M serum levels could prove to be a useful marker in assessi ng not only the activity, severity, and extent of CD but the treatment effi cacy as well. (C) 2001 by Am. Cell. of Gastroenterology.