Table 2.

Immunostaining of kidney allograft infiltrating cells in the 29 biopsies showing rejection^*

	Kidney Allograft Biopsies (N=29)
Immunophenotyping of Infiltrating Cells*	Acute T Cell Mediated Rejection	Active Antibody Mediated Rejection	Chronic Active Antibody Mediated Rejection	Kruskal- Wallis Test	Dunn’s Post Test
	N=11	N=7	N=11		Acute T Cell Mediated Rejection vs. Active Antibody Mediated Rejection	Acute T Cell Mediated Rejection vs. Chronic Active Antibody Mediated Rejection	Active Antibody Mediated Rejection vs. Chronic Active Antibody Mediated Rejection
	Cells per high power field, median (IQR)
CD3+ T cells	315 (280–438)	102 (18–221)	220 (113–270)	0.001	<0.01	<0.05	>0.05
CD68+ Macrophages	223 (155–265)	84 (56–175)	144 (100–200)	0.036	<0.05	>0.05	>0.05
CD20+ B cells	16 (10–23)	11 (5–16)	2 (0.5–6)	0.032	>0.05	<0.05	>0.05

^*Immunohistochemical staining for CD3+ T cells, CD68+ monocytes/macrophages and CD20+ B cells was performed on all kidney allograft biopsies showing acute TCMR, active ABMR or chronic active ABMR using CD3, CD68 and CD20 antibodies (Leica Biosystems, Buffalo Grove, IL), respectively, on paraffin embedded tissue sections on a Leica Bond system (Buffalo Grove, IL.) using the modified protocol F provided by the manufacturer. The section was pre-treated using heat mediated antigen retrieval with Tris-EDTA buffer (pH = 9, epitope retrieval solution 2) for 20 min and incubated with the antibodies for 15 min at room temperature. CD3, CD20 and CD68 were detected using an HRP conjugated compact polymer system and DAB as the chromogen. Each section was counterstained with haematoxylin and mounted with Leica Micromount. For each biopsy tissue sample, the total number of CD3, CD20 or CD68 positive cells in 5 high power fields (40X) in the nonsclerotic areas of the kidney allograft was counted and expressed as total number of cells per high power field. In the table, the median (IQR) number of CD3+ T cells, CD68+ monocytes/macrophages and CD20+ B cells for each diagnostic category is shown. Kuskal-Wallis test was used for comparisons across the three-biopsy diagnostic categories and the Dunn’s posttest was used for pair-wise comparisons. Statistically significant (P<0.05) results are shown in bold.