Secondary (reactive) amyloidosis is a not very rare complication of chronic rheumatological disea- ses such as rheumatoid arthritis (RA), juvenile chronic arthritis (JCA), ankylosing spondylytis (AS). In addition to elevated levels of circulating SAA precursors a number of other factors participates in the development of the disease, incl. cytokines and growth factors. Renal affection is frequent and is a serious cause of morbidity and mortality of these patients. Severe nephrotic syndrome is encountered, impaired renal functions – glomerular as well as tubular. Treatment of patients with renal affections is not sufficiently effective and its results are very unsatisfactory. In JCA adminis- tration of chlorambucil is recommended in particular, in RA and AS chlorambucil, cyclophospha- mide, azathioprin. Long-term treatment is essential and side-effects must be foreseen. Perspectives are symptomatic treatment, i.e. renal transplantation, or causal treatment, i.e. bone marrow transplantation.

        Key words: amyloidosis of the kidneys, amyloid, rheumatoid arthritis, juvenile chronic arthritis, ankylosing spondylytis, nephrotic syndrome