Haematological abnormalities in systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterised by extremely high heterogeneity. This heterogeneity concerns the organ involvement, course of disease and prognosis. Unlike in some other systemic connective tissue diseases, especially systemic lupus erythematosus, in SSc haematological disorders occur rarely. When they develop, they affect erythrocytes, leucocytes and platelets. The most common cause of this pathology of erythrocyte abnormalities is microcytic anaemia resulting from micro-haemorrhages with telangiectasias within the digestive mucosa in patients with SSc. In SSc patients with severe haematological disturbances, the differential diagnosis should include overlapping with another systemic connective tissue disease or a haemato-oncological disease (lympho/myeloproliferative syndrome). In SSc patients with monoclonal proteins or cryoglobulins, it is essential to consider a haemato-oncological disease. In such cases, the differential diagnosis should be focused on a paraneoplastic syndrome, especially when the haematological symptoms develop shortly after the diagnosis of SSc and in the elderly.