Sarcoidosis in a patient with 5q-myelodysplasia. A possible pathogenetic link between the two diseases.

This study describes the occurrence of sarcoidosis with lung and skin involvements in a 56-yr-old woman who suffered from 5q-myelodysplastic syndrome since the age of 50. The 5q-myelodysplastic syndrome is marked by deletion of the long arm of chromosome 5, which carries the genes coding for T-helper cell 2 cytokines, such as interleukins-3, -4 and -5, and granulocyte-macrophage colony-stimulating factor. Although the aetiology of sarcoidosis remains unclear, sarcoid granulomatous inflammation is marked by predominant expression of T-helper cell 1 cytokines, with reduced expression of T-helper cell 2 cytokines. The authors suggest that 5q-abnormality may have predisposed to sarcoidosis through an imbalance in the cytokine network, caused by the deletion of genes coding for T-helper cell 2 cytokines.