PROTOTYPICAL HTLV-I II INFECTION IS RARE IN LGL LEUKEMIA/

The etiology of LGL leukemia is not known; however, we recently detect ed HTLV-II in a patient with LGL leukemia. In this study, we found tha t sera from 6 of 28 patients with LGL leukemia were positive for HTLV- I/II using a whole virus ELISA; moreover, the ELISA-negative sera were near the positive cut-off value. Therefore, we performed additional s tudies on these sera using commercially available assays which can con firm and distinguish HTLV-I from HTLV-II infection. Serum from on ly o ne patient was confirmed positive using conventional criteria (HTLV-II +). Sera from 25 patients (89%) had indeterminate reactivity on Wester n blot assays. Of these, sera from 21 (84%) reacted to gag protein p24 ; 12 (48%) reacted with recombinant env protein p21e, and 10 (40%) rea cted with both. We could not detect HTLV-I/ II pol or pX gene sequence s in these patients using polymerase chain reaction analyses, with the exception of the HTLV-II-infected patient described previously. These data show that most patients with LGL leukemia are not infected with prototypical HTLV-I or HTLV-II. The frequent reactivity of patient ser a to HTLV-I/II gag protein p24 and to env protein p21e, however, sugge sts that a deleted or variant farm of HTLV-I/II may be associated with LGL leukemia.