Journal of Autoimmunity zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE (1992) $581-590 Incidence and Phenotype Restriction of Lymphoid BLT-serine Protease Granules in Spontaneously Diabetes Prone BB Rats Compared with a Normal Rat Strain Ludwig Wagner, Wolfgang Base, Martin Wiesholzer, Veronika Sex& Clemens Fiirnsinn, Gertraud Lang,* Johann Froschauer* and Werner Waldhlusl 1st Department of M edicine, University zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK of Vienna, Lazarettgasse 14, A-1090 Vienna and *Interne Abteilung, LKH Schaerding, Kubinstrasse 100, A-4780 Schaerding, Austria (Received 12 February 1992 and accepted 18 May 1992) In diabetes prone BB rats a relative increase of serine protease (SP)- positive lymphocytes (39.8 f loo/ ) 0 was observed in peripheral blood at the time of diabetes manifestation (DM) compared with non-diabetic healthy Sprague Dawley control rats (Co: 10.3 + 4%), with BB rats at age of pre- manifestation (PM: 14.7 + 4%) and beyond age of expected manifestation (non-diabetic animals, ND: 25.2 f 4%). Similar absolute numbers were found in diabetic BB rats in comparison with Sprague Dawley rats. In PM, absolute numbers were lower in comparison with diabetic BB rats. SP granular positivity was found restricted to 0X8+ lymphocytes. SP granule-bearing 0X8+ lymphocytes were more frequently seen in the BB rat strain (PM: 74.3 28%; DM: 79.4$-S%; ND: 78+ 10%) compared with normal rats (Co: 32.5 + 8%). Absolute numbers were lower in PM animals in comparison with DM rats. 0X8+ cells were found in a higher relative number in DM animals (49.1 f 7%) compared with controls (28.2 f 3%), PM (26.3+5%) and ND (34+2O/) o animals. T lymphocytes expressing the W3/25 + marker, invariably negative for SP granules, were present in a higher relative number in ND (49.8f7%) and the control group (52.3 k 10%) compared with PM (31+ 8%) and DM (38 Ifr 11%) animals. Absolute numbers of the 0X39+ lymphocyte subpopulation were decreased in PM and DIM-BB rats in comparison with the control group. zyxwvutsrqponmlkjihgfedcbaZYX Correspondence to: Ludwig Wagner, MD, Alfred KubinstraBe 100, A-4780 Schaerding, Austria. Fax: (7712) 31417236. 581 0896-841 l/92/050581 + 10 $08.00/O 0 1992 Academic Press Limited