The importance of granulocyte elastase in haematological diagnosis

Abstract

PMN elastase is a useful additional parameter in the differential diagnosis of the leukaemias. In all patients with myelocytic leukaemias there were elevated levels of elastase-α₁-proteinase inhibitor (E-α₁PI), while in the lymphatic leukaemias complexed elastase levels were decreased. The highest values were found in the peripheral blood plasma and bone marrow plasma of patients with CML. Despite high E-α₁PI concentrations there were no signs of bleeding or consumption of plasmatic coagulation factors. In AML a wide range of E-α₁PI levels was observed, extending from slightly elevated to four hundred-fold increased. In myeloblastic leukaemias without maturation (FAB M1) the concentrations of complexed elastase remained below 150 ng/ml. In myeloblastic leukaemias with maturation (FAB M2) the E-α₁PI values ranged between 214 ng/ml and 850 ng/ml (x= 402 ± 69), and in myelo-monoblastic leukaemias (FAB M4) between 450 ng/ml and 720 ng/ml (x = 663 ± 72). The only case of promyelocytic leukaemia (FAB M3) exhibited an extremely high value of 4,550 ng/ml, while a monocytic leukaemia (FAB M5) showed an extremely low value of 5 ng/ml. During cytostatic therapy there was a rapid decrease in levels of complexed elastase, with E-α₁PI values returning to normal in remission. In recidivating cases there was an increase of E-α₁PI levels in AML and a decrease in ALL. There was a correlation between the E-α₁PI concentrations in peripheral plasma and leukaemic bone marrow infiltration, so providing a good basis for monitoring remission from leukaemia and indicating relapse. It was also interesting to observe an extremely low E-α₁PI level (5 ng/ml) in patients with myelodysplasia. Under Decortin/Plenastril therapy the concentration rose to 50 ng/ml. An E-α₁PI level of 10 ng per ml was observed in one case of Ranitidine agranulocytosis. Under corticoid therapy the value returned to normal within eight days.