STAINING PATTERN OF 7 MONOCLONAL ANTI-CD26 ANTIBODIES IN LEPROSY - IMPLICATIONS FOR THE USE OF CD26 AS A SURROGATE MARKER OF A HUMAN TH1-LIKE REACTION

In a previous study using the monoclonal anti-CD26 antibody MIB-DS2/7 in leprosy and other granulomatous diseases, it was shown that CD26 ma y be a candidate for use as an operational marker of a human Th1-like reaction. In this follow-up study, we compared seven different monoclo nal anti-CD26 antibodies with respect to their staining pattern in lep romatous and tuberculoid leprosy tissues. Three distinct staining patt erns became apparent in this anti-CD26 antibody panel: staining of T-l ymphocytes and of connective tissue; staining of T-lymphocytes, connec tive tissue and macrophages; and almost no staining of T-lymphocytes b ut staining of connective tissue and macrophages. The two antibodies a ssigned to the first staining pattern, including MIB-DS2/7, were found to be most suitable for the operational discrimination between Th1-li ke and Th2-like reactions in leprosy, The antibodies assigned to stain ing patterns 2 and 3 did not allow this discrimination. Although all s even monoclonal antibodies investigated were specific for CD26, only t wo were found to be useful in identifying a Th1-like immune reaction i n human tissue.