Table 4.

Correlation of HIF-1α and HIF-2α expression with MVD, VEGF/KDR activated MVD, and PD-ECGF expression by synovial lining and stromal cells, and with bcl-2 expression, in the rheumatoid and osteoarthritic synovium

	HIF-1α			HIF-2α
	Low	High	P	Low	High	P
Rheumatoid arthritis
Standard MVD	57 ± 10	63 ± 7	0.16	61 ± 6	59 ± 10	0.63
Activated MVD	27 ± 12	34 ± 10	0.14	31 ± 10	31 ± 12	0.97
% PD-ECGF lin. cells	50 ± 13	55 ± 24	0.57	50 ± 30	54 ± 12	0.65
% PD-ECGF str. cells	82 ± 10	81 ± 9	0.95	80 ± 10	82 ± 9	0.51
% bcl-2	4 ± 8	2 ± 4	0.54	0 ± 0	5 ± 7	-
Osteoarthritis
Standard MVD	58 ± 10	73 ± 18	0.01	68 ± 23	66 ± 11	0.71
Activated MVD	15 ± 3	18 ± 4	0.01	16 ± 3	17 ± 4	0.46
% PD-ECGF lin. cells	51 ± 14	68 ± 21	0.01	55 ± 18	66 ± 21	0.14
% PD-ECGF str. cells	30 ± 17	49 ± 26	0.01	34 ± 18	47 ± 21	0.13
% bcl-2	5 ± 8	32 ± 25	0.0007	18 ± 25	25 ± 23	0.46

HIF, hypoxia inducible factor; lin., synovial lining; MVD, microvessel density; OA, osteoarthritis; PD-ECGF, platelet-derived endothelial cell growth factor; RA, rheumatoid arthritis; str., stromal.