Page 140 - Haematologica - Vol. 105 n. 6 - June 2020

W. Townsend et al.
ICOSpos with 53.9% ±14.2 of Ki67pos cells in contact with PD-1posICOSpos cells. In GC light zones, Ki67pos B cells were significantly more likely than Ki67neg B cells to be in con- tact with TFH in all cases studied (P<0.005 in each GC examined) (Figure 2C).
In the highly proliferative dark zones, there were few TFH and a very high number of Ki67pos B cells. The closely packed Ki67pos B cells could not be separated by automated image analysis and therefore accurate calculation of the proportion of Ki67pos cells in contact with TFH could not be performed in the dark zones. It is clear from visual inspec-
tion, however, that the degree of spatial correlation between these cells is much lower in the dark zones than in the light zones (Figure 2B).
A close spatial relationship between Ki67pos B cells and CD4posPD-1Hi T cells was also found in FL and, in contrast to normal GC, all areas with high Ki67 also had increased numbers of TFH cells. In FL 41.0% ± 13.6 of CD20posKi67pos cells were found to be in direct contact with CD4posPD-1Hi cells, although the level of co-localiza- tion was significantly lower than in GC (P=0.003), there was a high level of co-localization in both settings
A
P<0.0001 P<0.0001
P=0.009
B
P=0.0223 P=0.018
C
P=NS P=NS
P=NS
r=0.90, P<0.0001
r=0.79, P<0.0001
P=NS
r=0.47, P=0.001
Figure 4. Association between Ki67 and number of follicular helper T cells in follicular lymphoma. (A) The area of the Ki67 binary layer correlates closely with the number of Ki67pos cells automatically counted (left) and the area of the Ki67 binary layer is significantly higher in grade IIIa or IIIb disease than in grade I-II disease (right), n=99 images from n=23 samples. (B) The number of Ki67pos cells correlates closely with the number of PD1pos ICOSpos cells (left) and there are significantly more follicular helper T cells (TFH) (as represented by increased area of PD1/ICOS intersection) in grade IIIa and IIIb disease than in grade I-II disease (right), n=42 images from n=13 samples. (C) The degree of TFH – Ki67 interaction is weakly associated with the number of Ki67pos cells (left), and the proportion of Ki67pos cells in contact with TFH does not differ significantly according to histological grade disease (right) (n=42 images from n=13 samples).
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