Immunohistochemistry of bone marrow extracellular matrix in ph-negative myeloproliferative diseases

Abstract

Introduction Evaluation of immunohistochemical expression of matrix metalloproteinases 2 and 9 (MMP2, MMP9), their inhibitors (TIMP1, TIMP2), fibroblast growth factor (FGF2), transforming growth factor beta (TGFB1) and collagen type III in the bone marrow of patients with Ph-negative myeloproliferative neoplasms (MPN) is of great importance.The aim of the study was the evaluation of expression of extracellular matrix components (MMP-2, MMP-9, TIMP1, TIMP-2, FGF2, TFGB1, Collagen III) involved in myelofibrosis progression in bone marrow trepan biopsies depending on mutational status of patients with CMPD.Materials and methods We analyzed 108 bone marrow biopsies of patients with MPN, which were divided into 3 groups: JAK2-positive (n=62), CARL-positive (n=25) and triple-negative (n=21). Whole-slide sections were immunostained using antibodies against MMP-2, MMP-9, TIMP-1, TIMP-2, FGF2, TGFB1, collagen type III and scored by ImageJ plugin software. We used Kruskal- Wallis test and Mann-Whitney U-test for comparisons of differences in medians. Spearman’s rank order correlation was calculated. Statistical significance was set at p<0,05.Results and Discussion MMP2 expression was observed in megakaryocytes. MMP9 expression was observed in neutrophils, macrophages and the bone marrow extracellular matrix (EM). TIMP1 expression was observed in the EM. TIMP-2, FGF2, TGFB1 and collagen type III expression was observed in megakaryocytes and the EM. Kruskal-Wallis test determined the differences between all 3 groups (MMP- 2 p< 0,001, MMP-9 p=0,023, TIMP-1 p< 0,001, TIMP-2 p< 0,001, FGF2 p< 0,001, TGFB1 p< 0,001, collagen type III p< 0,001). Mann-Whitney U-test determined the most differences between JAK2- and CALR-groups (MMP-2 p=0,001, MMP-9 p=0,001, TIMP-1 p=0,001, FGF2 p=0,001, TGFB1 p=0,001, collagen type III p=0,001), except TIMP-2. There was the weak and moderate positive correlation between JAK2-mutation and the immunohistochemistry expression of EM components, also the weak negative correlation between CALR-mutation and the immunohistochemistry expression of EM components.Conclusion The bone marrow immunohistochemistry expression of MMP-2, MMP-9, TIMP-1, TIMP-2, FGF2, TGFB1, collagen type III depends on driver mutations. It may be useful for understanding of fibrosis pathogenesis and prognosis estimate of Ph-negative MPN.