Haffner D - In children and adolescents with systemic lupus erythematosus (SLE) the assessment of renal involvement is of special importance with respect to long-term morbidity and mortality. In particular, patients presenting with diffuse-proliferative lupus nephritis may develop irreversible progressive renal failure in spite of rather mild clinical symptoms at initial presentation. Pharmacological treatment in this age group must also place emphasis on the specific problems of growth and development (longitudinal growth, puberty, gonadal function) as well as on psychological issues (non-compliance). Thus, close cooperation between paediatric rheumatologists and nephrologists is mandatory to provide optimal care for children with SLE.