Ann Rheum Dis: first published as 10.1136/ard.46.6.492 on 1 June 1987. Downloaded from

492 Correspondence

absence of another cause such as renal failure or liver Table 1 Phenotvpes of DW4 or Dw/4 positive patients, or disease), as has been previously suggested; however, it can patients positive for both also be associated with an acute phase reaction, and this should be borne in mind when interpreting the significance Patient.s witliout Patients with of VWF measurements. toxch- effects toxic eff cts ( =23) (0t =61) MRC Clinical Research Centre. J L GORDON Dw4/x or -, 6 13 Harrow. B E POTTINGER DwI4/x or - 2 6 Middlesex P woo Dw4/w14 5 () H6pital Henri Mondor. J ROSENBAUM "D typing missed in one patient. Paris .x means any other HLA-D specificitNr found. West Middlesex Hospital. C M BLACK 'In DR typing only DR4 was found. Isleworth. Middlesex group. which was more heterogeneous as to the American References Rheumatism Association criteria.-' Although we emphasised the differences in Dw4 and I Jaffc E A. Hoyer L W. Nachman R L. Synthesis of von Willebrand antihemophilic factor antigen by cultured human Dwl frequencies between the groups. the higher Dw14 cndothelial cells. Proc Natl Acad Sci USA 1973: 71: 1906-9. prevalence in the RA controls with classical RA was 2 Sakariassen K S. Bolhuis P A. Sixma J J. Human blood platelet disregarded in the discussion. adhcrence to artery subendothelium is mcdiated by factor VlIl- Recently, Dr Nepom and colleagues identified HLA- von Willebrand factor bound to the subendothelium. Nature Dw4/w14 heterozygosity by allele specific oligonucleotide 1979; 279: 636-8. probes in five out of seven phenotypically DR4 homozy- 3 dc Groot P G. Gonsalves M D. Locsberg C. van Buul- gous (RA) patients who were found among 45 selected Wortelbocr M F. van Aken W G. van Mourik J A. Thrombin- Caucasian RA and seropositive induced reease of von Willebrand factor from endothelial cells patients with classical is mcdiated by phospholipid methylation. Prostacyclin synthesis disease. They proposed that their report was the first to is independent of phospholipid methylation. J Biol Chesn 1984; describe high Dwl4 in adult RA and suggested that thecopyright. 259: 13329-33. Dw14 allele may play an important part in susceptibility to 4 Angles-Cano E. Sultan Y. Clauvel J P. Predisposing factors to RA. thrombosis in systemic lupus erythematosus. Possible relation We have now re-evaluated our series with regard to to endothelial cell damage. J Lab Cliti Med 1979; 94: 312-23. Dw4/Dw14 status. The table shows the phenotypes of Dw4 5 Kahaleh M B. Osborn 1. LeRov E C. Increased factor VIII/von or Dwl4 positive patients. or patients positive for both, in Willcbrand factor antigen and von Willebrand factor activity in each group. The five Dw4/w14 heterozygotes in the group scieroderma and in Ravnaud's phenomenon. Atiti Itnteris Med 1981: 94: 482-4. with classical RA without gold toxicity was significantly 6 Nusinow S. Fcderici A B. Zimmerman T S. Curd J G. more than the expected number of 2()9 calculated from thehttp://ard.bmj.com/ Incrcased von Wiilebrand factor antigen in the plasma of phenotype frequencies (X-=4(05. p<0(05). Instead, none patients with vasculitis. Arthritis Rheutoi 1984; 27: 140)5-11). of the patients with gold toxicity was Dw4/w14 hetero- 7 Lee P. Norman C S. Sukenik S. Alderdiec C A. The clinicial zygous. Our results obtained with cellular HLA-D typing significaince of coagulation abnormalities in systemic scierosis thus agree with those of Dr Nepom and colleagues (scleroderma). J Rheutnatol 1985; 12: 514-7. concerning classical RA. Although the Dw4 and Dw14 8 Glueck H 1. Kant K S. Weiss M A. Pollak V E. Miller M A. genes both may be associated with disease susceptibilitv Coots M. Thrombosis in systemic lupus erythematosus. Rela- tion to the presencc of circulating anticoagulants. Arc/h Ititerus (gene). their effect on the clinical picture of RA max be even stronger. Med 1985; 145: 1389-95. on September 28, 2021 by guest. Protected 9 Kelly D. Tuddenham E G D. Summerfield J A. The effect of an acute phase reaction and BCG inoculation on ftactor Vil in the Department of Medicine. NIARKKLI HAKALA guinea pig. T/srornh Res 1985; 40: 445- 1. Paivarinne Hospital. Muhos. Finland National Public JORMA ILONEN Health Institute. HLA antigens Dw4 and Dw14 in Oulu, Finland Department of ANJA TIILIKAINEN rheumatoid arthritis Medical Microbiology. University of Oulu, SIR. In a recent study in the Annals of Rheumatic Diseases Oulu, Finland we assayed the differences in HLA system of 62 patients with rheumatoid arthritis (RA) with various toxic effects of References gold salts and 23 RA controls without gold toxicity.' The I Hakala M. vain Assendelft A H W. Iloncn J. Jalasa S. findings included higher Dw4 and Dwl4 and lower Dwl Tiilikainen A. Associiation of diffcrent HLA aintigcns with incidences in the controls with classical rheumatoid vairious toxic cffects of gold sallts in rhcumaitoid airthritis. Asiss arthritis (RA) when compared with the gold toxicity Rl/eun Dixs 1986; 45: 177-82. Ann Rheum Dis: first published as 10.1136/ard.46.6.492 on 1 June 1987. Downloaded from

Correspondence 493

2 Ropes M W. Bennett G A. Cobb S. Jacox R. Jessar R A. 6 Auscher C. Pasquier C. Mercier N. Delbarre F. Oxidation of Revision of diagnostic criteria for rheumatoid arthritis. Bull pyrazolo (3.4-d) pyrimidine in a xanthinuric man. Isr J Med Sci Rheu,n Dis 1958: 9: 175-6. 1973: 9: 3. 3 Nepom G T. Seyftied C E. Holbeck S L. Wilske K R. 7 Elion G B. Benezra F M. Caneilas 1. Carrington L 0. Hitchings Nepom B S. Identification of HLA-DwI4 genes in DR4+ G H. Effects of xanthine oxidase inhibitors on purine meta- rheumatoid arthritis. Lancet 1986: ii: 1(0)2-5. bolism. Isr J Clzetn 1968; 6: 787-96. 8 Rundles R W. Metz E N. Silberman H R. Allopurinol in the treatment of gout. Aiiii ltiter,i Med 1966: 64: 229-58. 9 Delbarre F. Amor B. Auscher C. De Gery A. Treatment of gout with allopurinol: a studv of 1t)6 cases. Ann,l Rheutn Dis Alternatives to allopurinol 1966: 25: 627-33. 10 Rundles R W. Metabolic effects of allopurinol and In their letter to the Annals Kelsey et al state that alloxanthine. Atiti Rheu,n Dis 1966: 25: 615-2). SIR, 11 Lockard 0 Jr, Harmon C. Nolph K. Irvin W. Allergic reaction there is 'no available alternative to allopurinol with its to allopurinol with cross-reactiyity to oxypurinol. Ann Intern unique mode of action'.' There are at least two alter- Med 1976; 85: 333-5. natives2; tisopurine (IH-pyrazolo[3,4-d]pyrimidine-4- thiol (CSH4N4S)) and oxypurinol (lH-pyrazolo[3,4-d] pyrimidine-4.6-diol(C,H4N402)). Neither are available in the United Kingdom. In the treatment of gout, tisopurine has been shown to reduce effectively both the plasma and urinary uric acid Hyper-responsiveness to EBV levels of hyperexcretors, but plasma levels only of normal in ankylosing spondylitis excretors. These effects were shown without a concom- itant increase in urinary hypoxanthine and xanthine excretion.-" Tisopurine is only one tenth as active as SIR. Recently, Drs Robinson and Panayi reported a allopurinol (1H-pyrazolo[3,4-dlpyrimidin-4-ol(C,H4N40)) deficient control of in vitro Epstein-Barr virus (EBV) as a xanthine oxidase inhibitor in vitro.7 and is ineffective infection in patients with ankylosing spondylitis (AS).' in lowering uric acid levels in gout associated with a partial Under blind study control, using peripheral blood mono- deficiency of the enzyme hypoxanthine guanine phos- nuclear cells from B27+ spondylitic patients, we have copyright. phoribosyl transferase.3 5 Therefore, tisopurine reduces observed a similar hyper-responsiveness to EBV. Cultures uric acid concentrations by interfering with the early stages were set up in quadruplicate in 96-well, flat bottomed of its synthesis, thus avoiding increased blood concen- microtitre plates. Virus supernatant, obtained from a 10 trations of hypoxanthine and xanthine. There is no day culture of B95-8 marmoset cells, was titrated and evidence that there is a cross reactivity between tisopurine mononuclear cells were added to each well to give a final and allopurinol. The dose range is from 200 to 400 mg concentration of 5 x 105 cells/ml. Fig. 1 shows the daily. minimum virus concentration required to immortalise the

Oxypurinol is the active metabolite of allopurinol in blood B cells of patients with either clinically active AS or http://ard.bmj.com/ vivo. Its half life is about eightfold longer than that of rheumatoid arthritis (RA). In these experiments, cells allopurinol.' Allopurinol is the more effective adminis- from 90% (9 of 10) of the spondylitic patients and 69% (11 tered orally in view of the relatively poor absorption of of 16) of the rheumatoid patients formed permanent cell oxypurinol from the gastrointestinal tract.' Although lines and the range of minimum concentrations was several patients with a history of untoward reactions to similar; the results are based on six week cultures. allopurinol have received oxypurinol without cross reac- Since we have shown previously an increased respon- tivity,"' others do cross react, and in some the reaction siveness to EBV of rheumatoid blood B cells2 we extended may have an immunological basis." the experiments further to evaluate the role of the spondylitic B cell in this observed hyper-responsiveness. on September 28, 2021 by guest. Protected Rheumatology Department, A S M JAWAD Non-T cells, negatively selected using 2-aminoethyliso- The London Hospital thiouronium bromide hydrobromide (AET) treated sheep erythrocytes, were infected with EBV supernatant at a References dilution of 1/10. Work from our laboratory has previously 1 Kelsey S M, Struthers G R, Beswick T. Blake D R. Desensitisa- shown this dose to be effective in the measurement of tion to allopurinol. Ann Rheum Dis 1987; 46: 84. hyper-responsiveness in RA.- Infected and uninfected cells 2 Reynolds J E F (ed). Martindale: The extra pharmacopoeia. were set up in 24-well, flat bottomed plates at a concentra- 28th ed. London: The Pharmaceutical Press. 1982: 419-22. tion of 5 x 10" cells/ml. The results of six week cultures are 3 Delbarre F. Auseher C, De Gery A. Brouilhet H. Olivier J L. shown in Table 1. In this study no healthy individuals were Le traitment de la dyspurinic goutteuse par la mercapto- used and the number of rheumatoid patients was small. pyrazolo-pyrimidine (MPP: thiopurinol). Presse Med 1968: 49: The results for the rheumatoid patients, however, were in 2329-32. agreement with our previous data from a larger study.- 4 Serre H. Simon L. Claustre J. Inhibitors of uric acid synthesis in the treatment of gout: a report of 126 cases. Semin Hop (Paris) There, we reported that no B cells from healthy controls 1970: 46: 3295-301. spontaneously grew into cell lines as compared with 22% 5 Grahame R. Simmonds H A. Cadenhead A. Dean B M. of the B cell samples from rheumatoid patients and only Metabolic studies of thiopurinol in man and pig. Isr J Med Sci 40% of infected healthy B cells were maintained in culture 1973; 9: 17. for six weeks; some of the 'normal' controls carried the