Mesenchymal stem cell transplantation for severe acute pancreatitis-associated lung injury: A meta-analysis of animal studies

Table 4 Subgroup analysis

Subgroup	Number of studies included	Test for heterogeneity		Effect model	SMD/WMD (95%CI)	P value
		I2 (%)	P value
Lung histopathology score
Stem cell type
BMSCs	13	86	< 0.001	Random	-2.95 (-3.96 to -1.93)	< 0.001
Non-BMSCs	6	89	< 0.001	Random	-2.87 (-4.46 to -1.29)	< 0.001
Transplantation route
Tail vein	17	83	< 0.001	Random	-2.37 (-3.12 to -1.62)	< 0.001
Femoral vein	2	79	0.03	Random	-8.09 (-12.90 to -3.28)	0.001
Transplantation duration
< 6 hours	12	89	< 0.001	Random	-3.34 (-4.50 to -2.18)	< 0.001
≥ 6 hours	7	79	< 0.001	Random	-2.15 (-3.29 to -1.00)	< 0.001
Follow-up duration
< 24 hours	10	88	< 0.001	Random	-3.21 (-4.46 to -1.95)	< 0.001
≥ 24 hours	9	86	< 0.001	Random	-2.62 (-3.79 to -1.46)	< 0.001
Lung MPO activity
Stem cell type
BMSCs	10	79	< 0.001	Random	-3.03 (-4.22 to -1.85)	< 0.001
Non-BMSCs	2	39	0.2	Random	-2.56 (-4.15 to -0.97)	0.002
Transplantation route
Tail vein	8	78	< 0.001	Random	-4.39 (-6.35 to -2.43)	< 0.001
Femoral vein	4	69	0.02	Random	-2.00 (-2.93 to -1.07)	< 0.001
Transplantation duration
< 6 hours	5	87	< 0.001	Random	-7.32 (-12.13 to -2.51)	0.003
≥ 6 hours	7	58	0.03	Random	-2.24 (-2.98 to -1.50)	< 0.001
Follow-up duration
< 24 hours	6	81	< 0.001	Random	-3.07 (-4.91 to -1.22)	0.001
≥ 24 hours	6	79	< 0.001	Random	-4.47 (-6.82 to -2.12)	< 0.001
Lung wet/dry weight ratio
Stem cell type
BMSCs	16	89	< 0.001	Random	-0.46 (-0.61 to -0.32)	< 0.001
Non-BMSCs	2	0	0.33	Random	-0.87 (-1.13 to -0.61)	< 0.001
Transplantation route
Tail vein	16	88	< 0.001	Random	-0.50 (-0.66 to -0.34)	< 0.001
Femoral vein	2	95	< 0.001	Random	-0.54 (-1.02 to -0.06)	0.03
Transplantation duration
< 6 hours	16	89	< 0.001	Random	-0.46 (-0.61 to -0.32)	< 0.001
≥ 6 hours	2	0	0.33	Random	-0.87 (-1.13 to -0.61)	< 0.001
Follow-up duration
< 24 hours	14	84	< 0.001	Random	-0.46 (-0.59 to -0.33)	< 0.001
≥ 24 hours	4	94	< 0.001	Random	-0.62 (-1.11 to -0.13)	0.01

SMD: Standardized mean difference; WMD: Weighted mean difference; CI: Confidence interval; BMSCs: Bone marrow mesenchymal stem cells; MPO: Myeloperoxidase.