Pathologic parameters and pathologic grading of disease severity
Assessment of inflammatory reaction and edema | The number of inflammatory cells within the lamina propria was systematically assessed on paraffin sections stained with hematoxylineosin. Cell counts were based on an individually defined mucosal tissue unit consisting of a 4-μm thick and 500-μm block of tissue overlying 200-μm of muscularis mucosae. The results are expressed as the mean number of cells per field. Edema was assessed according to the intensity: none (0), mild (1), or severe (2). |
| Analytic count of neutrophils and eosinophils | The number of neutrophils and eosinophils was assessed on paraffin sections, stained with May-Grünwald-Giemsa. The density of tissue neutrophils and eosinophils per field at × 400 was graded as follows: no cells, 0-10, 10-20, and > 20 cells/field. |
| Analytic count of lymphocytes | The number of lymphocytes was assessed on paraffin sections. The density of lymphocytes per field at the same magnification was graded as follows: < 20, 20-40, and > 40. |
| Analytic count of cells stained by immunohistochemistry | The number of cells stained with antibodies directed against CD45, CD68 (for macrophages), and TNF was assessed on cryocut sections. The density of these stained cells was graded as follows: no cells, 0-10, 10-20, 20-30, and > 30 cells. |
| The number of cells stained with antibodies directed against Fas, and the 2 different types of TNFRs were assessed on cryocut sections. The cells stained by one of these antibodies was graded as follows: no cells, 1-5, and > 5 cells. A differential count was made for stained cells in the epithelium and in the cellular infiltrate. | |
| Analytic count of the cells stained by the TUNEL assay | The number of cells stained was assessed on paraffin sections. The density of the stained cells was graded as follows: no cells, 1-5, 5-10, and > 10 cells. Because neutrophils are a major component of the cellular infiltrate in some biopsies, and are prone to apoptosis, the distribution of stained cells between the epithelium and the cellular infiltrate was taken into account. |
Assessment of inflammatory reaction and edema | The number of inflammatory cells within the lamina propria was systematically assessed on paraffin sections stained with hematoxylineosin. Cell counts were based on an individually defined mucosal tissue unit consisting of a 4-μm thick and 500-μm block of tissue overlying 200-μm of muscularis mucosae. The results are expressed as the mean number of cells per field. Edema was assessed according to the intensity: none (0), mild (1), or severe (2). |
| Analytic count of neutrophils and eosinophils | The number of neutrophils and eosinophils was assessed on paraffin sections, stained with May-Grünwald-Giemsa. The density of tissue neutrophils and eosinophils per field at × 400 was graded as follows: no cells, 0-10, 10-20, and > 20 cells/field. |
| Analytic count of lymphocytes | The number of lymphocytes was assessed on paraffin sections. The density of lymphocytes per field at the same magnification was graded as follows: < 20, 20-40, and > 40. |
| Analytic count of cells stained by immunohistochemistry | The number of cells stained with antibodies directed against CD45, CD68 (for macrophages), and TNF was assessed on cryocut sections. The density of these stained cells was graded as follows: no cells, 0-10, 10-20, 20-30, and > 30 cells. |
| The number of cells stained with antibodies directed against Fas, and the 2 different types of TNFRs were assessed on cryocut sections. The cells stained by one of these antibodies was graded as follows: no cells, 1-5, and > 5 cells. A differential count was made for stained cells in the epithelium and in the cellular infiltrate. | |
| Analytic count of the cells stained by the TUNEL assay | The number of cells stained was assessed on paraffin sections. The density of the stained cells was graded as follows: no cells, 1-5, 5-10, and > 10 cells. Because neutrophils are a major component of the cellular infiltrate in some biopsies, and are prone to apoptosis, the distribution of stained cells between the epithelium and the cellular infiltrate was taken into account. |
The counts were performed on an Olympus Provis AX 70 microscope, in 3 different areas with wide-field eyepiece number 26.5. At × 400, this wide-field eyepiece gives a field size of 0.344 mm2.