Leucocytic alkaline phosphatase activity in leprosy: a possible guide in the follow-up of leprosy.

In order to investigate a possible involvement of phagocytic cells in the various types of leprosy, we undertook the study of enzymatic activities in circulating leucocytes. The activity of leucocytic alkaline phosphatase was studied by histochemical techniques on blood smears in 31 patients presenting with leprosy and aged between 4 and 73, and in 11 non infected people. The 31 patients suffering from leprosy were distributed as following: 14 lepromatous leprosy of which 6 had not yet been treated and 8 were under treatment, 9 cases of tuberculoid leprosy of which 7 had been treated and 2 had not yet, 3 cases of borderline leprosy which had all been treated, and 5 patients whose form of leprosy was indeterminate (before treatment). The distribution of the different values we obtain shows a very significant difference (p less than 0.001) between patients with and without leprosy (respectively 33.8 +/- 7.3 and 109.8 +/- 12.5). Moreover, the decrease of the alkaline phosphatase activity correlated with the severity of the disease (47.2 +/- 11.4 in tuberculoid leprosy and 20.6 +/- 9.3 in lepromatous leprosy) thus suggesting that the evaluation of leucocytic alkaline phosphatase activity should be advised as a possible prognosis guide in indeterminate leprosy.