Brief Reports

Vox Sang. 21: 65-68 (1971)

The HL-A Antigen, LND ( = W15)

E. THORSBY, C. M. VAN DER WEERDT and V. C. JOYSEY

Tissue Typing Laboratory, Rikshospitalet University Hospital, Oslo; Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam, and The John Bonnett Clinical Laboratories, Addenbrooke’s Hospital, Cambridge

During the last few years an increasing number of HL-A antigens has been identified, and a t the last International Histocompatibility Conference several teams reported on about 10 or more antigens of each of the two HL-A series [5 ] . The Fourth Histocompatibility Work- shop revealed that many of these specificities could be recognized by several closely correlated lymphocytotoxic antisera [l]. However, some of the more recently identified specificities were not as yet satia- factorily defined. One of these was the LND specificity, which was provisionally designated W15.

The original serum detecting this specificity (TH-LND) was ob- tained by immunization of a recipient which is HL-A2,3,7, 12 with cells from a donor where only HL-A2 could be detected [6,7]. After 3 injections of leucocytes lymphocytotoxic antibodies against donor cells were detected, and population and family studies strongly indi- cated that the antiserum revealed a ‘new’ antigen (called LND) of the second HL-A series. However, due to insufficient amounts of the original reagent only serum obtained after reimmunisation of the reci- pient could be included in the Workshop, where it was found that this later bleeding also contained antibodies against Maki (= Wl4), and possibly also against W17. Two other sera were also found to be correlated to serum LND, namely En-CLB 10, and Joy-Moore, but these were also found in some laboratories to include W17 in addition to the LND specificity [l].

Received: December 10, 1970; accepted: January 4, 1971.

66 THORSBY~VAN DEB WEERDTIJOYSEY

Table I. Correlations between the different LND sera (unrelated individuals only)

Antbenun +/+ +/- -/+ -1- Total

I I1

TH-LND 280169 TH-LND 280169 TH-LND 280169 TH-LND 280169 Joy-Moore En-CLB 10 1 :2 Joy-Moore TH-WGJ 200570

En-CLB 10 En-CLB 10 1 : 2 Joy-Moore TH-WGJ 200570 TH-WGJ 200570 TH-WGJ 200570 Joy-Sired Joy-Sued

13 0 7 33 53 31 1 0 126 158 52 2 1 186 241 52 2 2 185 241 60 1 3 244 308 23 0 2 90 115 54 3 0 278 335 4 1 0 37 42

+/+ Number of individuals positive with both sera. +/- Number of individuals positive with serum I and negative with serum 11. -/+ Number of individuals negative with serum I and positive with em 11. -/- Number of individuals negative with both sera.

We have recently compared the original LND serum with these latter antisera and others, using own techniques.' The results obtained in our three laboratories were pooled and appear from table I. Serum En-CLB 10 diluted 1 :2 is almost identical to the original LND serum, but also gives positive reactions undiluted with W17. Serum TH-WGJ was produced by immunization of a recipient which is HL-A 1, 3 , 8 by 3 monthly lymphocyte injections from a donor being HL-A1,3,8, LND. The table shows that this serum is also closely correlated to the other LND sera. Both sera Moore and Sired were produced by iso- immunization during pregnancy and are closely correlated with TH- LND, TH-WGJ and En-CLB 10.

These results show that the LND specificity can be detected by several closely correlated antisera. It is apparent that none of the 5 different antisera are completely identical, but the inconsistent reactions were usually much weaker than those caused by the common specificity of the different sera, and most probably are due to weak extra antibodies.

The LND antigen can thus now be fairly well-recognized, a t least when 2 or more of the reported lymphocytotoxic antieera are used.

E. T.: Microlymphocytotoxicity [3]; C. M. W.: Microlymphocytotoxicity, NIH technique with trypan blue instead of eosine; W. C. J.: Microlymphocytotoxicity [2].

The HL-A Antigen, LND (=W15) 67

Table ZI. Antigen and gene frequencies of LND (= W15)

Nationality Number Number % Gene investigated p o ~ . ~ positive, A frequency

British 335 54 16.12 0.084 Dutch 144 26 18.06 0.095 Norwegian 172 33 19.19 0.101

Unrelated individuals only. Positive with 2 or more of the reported antisera.

8 p = 1-YI-A.

The specificity can also be identified by the complement fixation test on platelets [4]. This is encouraging for histocompatibility testing since the antigen is frequent among Europeans, as shown in table 11. Our latest population and family studies also support the previous assumptions [6,7] that the antigen is determined by an allele a t the 2nd HL-A sub-locus, since none of the LND positive individuals has been found to possess more than 1 additional antigen of the 2nd series, and the specificity has in families always been found in the repulsion phase with respect to other determinants a t the 2nd sub- locus.

Summary

Further studies of the specificity LND of the 2nd HL-A series are presented. The antigen can now be fairly well-recognized by several closely correlated antisera, which is encouraging for histocompatibility testing since the antigen is quite fre- quent,

Acknowledgements

Our work has been aided by Professor Carl Semb’s Fund, donations from Mr. ANDERS JAHRE. Medical Research Council and United Cambridge Hospitals. The skilled assistance of Miss ANNE BRATLIE, Mrs. L. E. VEENEOVEN-VON RIESZ. Mrs. A. JONES and Mrs. M. WILKINSON is gratefully acknowledged.

References

1. ALLEN et d.: Joint report of 4th Int. Histocompatibility Workshop; in Histo- compatibility (testing 1970, pp. 17-47 (Munksgaard, Copenhagen 1970).

2. JOYSEY, V. C.: A modified microcytotoxic test for lymphocyte typing using siliconed glass slides and ordinary phase contrast microscopy; in Transplantation

68 THORSBY/VAN DER WEERDT/JOYSEY

antigens and tissue typing, pp. 125-130 (The Robert Jones and Agnes Hunt Orthopaedic Hospital Management Committee, Owestry, England 1969).

3. KISSMEYER-NIELSEN, F. and KJAERBYE, K. E. : Lymphocytotoxic micro-tech- nique. Purification of lymphocytes by flotation; in Histocompatibility testing 1967, pp. 381-383 (Munksgaard, Copenhagen 1967).

4. SVEJGMRD, A.; KISSMEYER-NIELSEN, F., and THORSBY, E.: HL-A typing of platelets; in Hietocompatibility testing 1970, pp. 153-163 (Munksgaard, Copen- hagen 1970).

5. TERASAKI, P. I. (ed.): Histocompatibility testing 1970 (Munksgaard, Copen- hagen 1970).

6. THORSBY, E. and KISSMEYER-NIELSEN, F. : New HL-A alleles. Identification by planned immunization. Vox Sang. I81 134-148 (1970).

7. THORSBY, E.; KISSMEYER-NIELSEN, F., and SVEJGAARD, A.: New alleles of the HL-A system. Serological and genetic studies ; in Histocompatibility testing 1970, pp. 137-151 (Munksgaard, Copenhagen 1970).

Authors' addresses : Dr. E. THORSBY, Tissue Typing Laboratory, Rikshospitdet University Hospital, Oslo I (Norway); Dr. C. M. VAN DER WEERDT, Central Labora- tory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam (The Netherlands); Dr. V. C. JOYSEY, The John Bonnett Clinical Laboratories, Adden- brooke's Hospital, Cambridge (England)