SERUM LAMININ P1 IN IDIOPATHIC MYELOFIBROSIS AND RELATED DISEASES

The serum concentration of laminin P1 antigen was determined in 32 pat ients with various myeloproliferative disorders, including 19 patients with idiopathic myelofibrosis. The serum concentration of the aminote rminal propeptide of type III procollagen (PIIINP) was measured concom itantly in 27 patients. Serial laminin measurements were carried out i n 25 patients. The median serum laminin concentration in patients with acute disease, i.e. acute myelofibrosis and patients in a transformin g disease phase was significantly higher (1.58 U/ml; range 1.15-2.07) as compared with patients with chronic disease (1.02 U/ml; range 0.75- 1.76; p = 0.012) and healthy control subjects (1.13 U/ml; range 0.75-1 .67; p = 0.00015). In individual patients serum laminin covariated clo sely with serum PIIINP, the leucocyte count and LDH. The median serum laminin concentration in patients with a huge spleen was significantly lower than in the patient group with a normal spleen size/previous sp lenectomy. Pronounced splenomegaly was particularly prevalent in patie nts with chronic disease implicating splenic enlargement as a signific ant extrahepatic site of laminin uptake/degradation in myeloproliferat ive disorders.