Haem biosynthesis studied in patients with rheumatoid arthritis.

In a study of the urinary excretion of haem precursors in patients with rheumatoid arthritis, iron-deficiency anaemia, and in healthy controls, certain differences were found. In iron-deficiency anaemia the excretion of both porphobilinogen and delta-aminolevulinic acid was increased, whereas in patients with rheumatoid arthritis only the porphobilinogen excretion was increased.A further study on the erythrocyte activity of delta-aminolevulinic acid dehydrase showed a higher activity in the erythrocytes from patients with rheumatoid arthritis compared with healthy controls.