Tissue Antigens (19761, 8, 355-357 Published by Munksgaard, Copenhagen, Denmark No part may be reproduced by any process without written permission from the author(s)

Summary Report on the Second New World B-Cell Workshop J.S. Thompson, W.E. Braun, C.B. Carpenter, J.B. Dossetor, B. Dupont, J.A. Falk, S. Ferrone, A.H. Johnson, J.F. Shaw, D.P. Singal, T.I. Terasaki, G.M. Troup, and R.L. Walford T h e Department of Medicine, University of Iowa, Iowa City, Iowa T h e Department of Immunopathology, Cleveland Clinic, Cleveland, Ohio T h e Department of Medicine, Peter Bent Brigham Hospital, Boston, Massachusetts T h e Department of Clinical Pathology, University of Alberta, Edmonton, Alberta, Canada T h e Department of Immunobiology, Memorial Sloan Kettering Cancer Center, New York, New York T h e Department of Surgery, University of Toronto, Toronto, Ontario, Canada T h e Department of Molecular Immunology, Scripps Clinic and Research Foundation, La Jolla, California T h e Department of Microbiology and Immunology, Duke University, Durham, North Carolina T h e Department of Pathology, University of Alabama Medical Center, Birmingham, Alabama T h e Department of Pathology, McMaster University, Hamilton, Ontario, Canada T h e Department of Surgery, University of California, Los Angeles, California T h e Department of Pathology, University of New Mexico, Albuquerque, New Mexico T h e Department of Pathology, University of California, Los Angeles, California

Received for publication 25 July 1976, accepted 19 August 1976

Thirteen laboratories participated in the second workshop and first American exchange of serum known to contain antibodies detecting specific B-cell antigens.

Details of this workshop are presented elsewhere (Thompson, et al. 1976), but the scope included 120 experimental and/or control sera that were tested against 268

356

1. S . THOMPSON E T A L

enriched peripheral blood B-cells (PBB), 103 chronic lymphatic leukemia cells (CLL) and 11 continuous lymphoid cell lines. T h e same sera were tested against 98 isolated T-lymphocyte preparations to determine residual anti-HLA-A, B and C activity. T h e methods of cell isolation and the specific lymphocytotoxic procedures were not standardized but the results from laboratory to laboratory with but one exception were remarkable for their general similarities. Comparative positive and negative controls revealed approximately 2% false positivity for the entire workshop. The majority of the sera were obtained from multiparous females. Several had been absorbed with platelets but a prolonged T-cell test with 2-hour complement incubation at room temperature revealed detectable anti-HLA reactions in a few of these as well as some unabsorbed reagents. Of particular interest was the comparison of the reactions of the sera defining six groups classified by Dr. Terasaki on PBB cells with those of sera detecting 11 Merrit groups described by Dr. Walford o n CLL cells. Several sera submitted by the other laboratories correlated with these same groups supporting the conclusions that distinct antigens were being detected on both PBB and CLL cells. There was a high degree of correlation noted between Terasaki group 1 and Merrit 13 (Table 1) with both target cells. This was not the case, however, with other correlations, i.e. I11 and IV with Merrit 1 and 6, that were determined on CLL but did not hold with PBB target cells. Furthermore, the sera detecting Terasaki groups I1 and VI failed completely to react with CLL cells but did show moderately good PBB correlations with Merrit 9, 13 and 6. In fact, it was common in this workshop for correlations between sera to vary when compared on the two substrates. Thus, 30 sera, free of T-cell lymphocytotoxicity were analyzed for correlations in excess of r =

Table 1 Comparison of two B-cell antigen classification systems TARGET CELL

CORRELATIONS Terasaki Walford r* (Menit)** 13 1 6

.76 .68 .57

I I

13

111

10 1

.65 .46 .44 .35

I

CLL

111

IV

PBB

111 IV I1

I1 VI

** *

7

-

-

9 13 6

.54

.5l .49

B-Cell Classification Systems r = correlation coefficient.

0.45. Whereas this degree was noted between the reactions of these selected reagents with those of other sera on 191 occasions with PBB and 127 with CLL, there were only 33 instances in which this correlation occurred with both target cells. This degree of variation suggests that there may be unique specificities unshared between normal and leukemic cell populations. Certainly, the failure of Groups I1 and VI to be detected on CLL is evidence in favor of this hypothesis and analysis of the reactions of a serum submitted by Dr. Dossetor strongly suggested that it detected a split of Merrit 13 that was present on CLL but absent on PBB cells. Further evidence is presented in the more complete report of the workshop. Finally, a possible association of the Blymphocyte reactions with HLA-A, B and C antigens was investigated. Excluding those sera with 1% or greater T-lymphocytotoxicity, correlations with HLA-A (A3) and with HLA-C (Cwl) antigens occurred on only one occasion each, whereas those with HLA-B (Bw41, B17, B8 and B13) were observed with 10 antisera. Of special interest

SUMMARY REPORT O N THE SECOND NEW WORLD B-CELL WORKSHOP

were five sera whose PBB B-cell specific reactions correlated with HLA-B13 and were also related to Merrit 13-Terasaki I. A similar but less pronounced PBB association was noted with four sera that correlated with HLA-B8 and two with HLA-B17. Therefore, although the correlations noted were generally weak, linkage disequilibrium between some B lymphocyte and HLA-B antigens appears to exist. Subsequent workshops will be necessary to confirm and amplify these observations, but this workshop served to identify many good sera detecting B-lymphocyte specificities, provided the basis for comparison of at least two tentative classification systems, demons-

357

trated the presence of apparently unique normal and leukemic as well as common B-cell antigens and suggested disequilibrium linkage of some of these specificities with HLA-B antigens.

Reference Thompson, et al. Report on the Second New World B-Cell Workshop. Transplant. Proc. (In press).

Address: Dr. John S. Thompson Department of Internal Medicine University of Iowa Iowa City, Iowa 52240