ABSTRACT
The intent of this study was evaluation of the role of some serum enzymes such as B-glucuronidase, B-galactosidase, monoamine oxidase, adenosine deaminase and 5 nucleotidase in the most common connective tissue diseases which are rheumatoid disease [RD], systemic lupus erythematosus [SLE] and progressive systemic sclerosis [PSS]. We also tried to determine whether these enzymes may be of value in differential diagnosis of these connective tissue diseases and whether there is any correlation between the levels of these enzymes and the activity of the disease. The study included 40 patients [20 RD, 10 SLE and 10 PSS] and ten healthy controls. Our results revealed that increased B-glucuronidase enzyme was found to be specific for rheumatoid disease and thus it can be used as a test to differentiate RD from other connective tissue diseases. Increased B- galactosidase activity was also found to be characteristic for progressive systemic sclerosis and can be used as a test for differentiating PSS from other connective tissue diseases. Determination of serum monoamine oxidase can be used as an index for fibrosis and serial determinations can be helpful for the assessment of the progress of fibrosis in any fibrotic disease