Table 1.

V-ATPase immuno-labeling demonstrates a progressive increase in intensity and loss of polarity from early PanIN lesions to pancreatic ductal adenocarcinoma (PDAC). Immunohistochemical staining of v-ATPase was graded by two independent pathologists based on intensity (upper panel) and distribution within the cells (lower panel) in randomly selected fields. The intensity score for normal ducts (1.24±0.43), low grade PanINs (1.72±0.45), high grade PanINs (2.56±0.50) and PDAC (all 3+) were significantly different among the groups, P<0.001. While the majority of normal pancreatic ducts showed a faint mixed basal/apical v-ATPase pattern, low grade PanINs mostly (86%) had a basal v-ATPase distribution within cells. The majority (94%) of high grade PanINs and all the PDAC had a diffuse distribution of v-ATPase compared to low grade PanIN lesions, P<0.001.

Histology	1+	2+	3+	Intensity score (mean ± SD)
Normal ducts	38/50 (76)	12/50 (24)	0/50	1.24 ± 0.43
Low grade PanIN	14/50 (28)	36/50 (72)	0/50	1.72 ± 0.45
High grade PanIN	0/50	22/50 (44)	28/50 (56)	2.56 ± 0.50
PDAC	0/50	0/50	50/50 (100)	3.00 ±0.00

Histology	Basal	Mixed basal/apical	Diffuse
Normal ducts	0/50	50/50 (100)	0/50
Low grade PanIN	43/50 (86)	5/50 (10)	2/50(4)
High grade PanIN	3/50(6)	0/50	47/50 (94)
PDAC	0/50	0/50	50/50 (100)