It is, therefore, found in serum and many other biological fluids. It forms part of the light chain of the HLA class 1 molecule, 4-6 and its amino acid sequence shows close homology with the constant regions of immunoglobulin heavy and light chains. Accepted for publication 31 December 1997. Received 18 October 1997. All patients were receiving at least one disease-modifying antirheumatic drug, including methotrexate, hydroxychloroquine, sulfasalazine and imuran.
All patients are female.
Disease activity should also have been present in the patient for at least four weeks. The controls selected were 25 normal, healthy age-matched female subjects who were not on any medication. Informed consent was obtained from each subject. Table 1 summarizes the demographic and clinical data of the study groups. Aliquots of urine samples were kept without additives at -70 C until analysis.