Immunohistochemical Characteristics of IgG4-Related Tubulointerstitial Nephritis: Detailed Analysis of 20 Japanese Cases

Table 3

Laboratory difference between IgG4-TIN patients with glomerular lesions and those without glomerular lesions.

	IgG4-TIN with GL	IgG4-TIN without GL	P value
Number of patients	9	11
Age (years), mean ± SD	73.8±7.2	66.0±7.7	0.036
Serum creatinine (mg/dL)	2.6±2.4	1.4±0.6	0.239
Serum IgG (mg/dL)	3865±903	3162±1251	0.16
Serum IgG4 (mg/dL)	909±434	935±413	0.909
SerumC3  (mg/dL)	43±23	70±27	0.068
Low C4	7/9	5/11	0.197
Low CH50	7/9	5/11	0.197
IgG4 IHC (cells per hpf)	43.0±21.8	44.5±39.4	0.493
IgG4/IgG (%)	50.4±16.5	54.1±20.8	0.518
IF TBM IgG	1/7	1/9	>0.999
IF TBM C3	4/7	3/9	0.615
IF TBM C1q	1/7	1/9	>0.999
EM TBM	2/6	4/9	>0.999

Note: Conversion factor for creatinine: mg/dL to μmol/L, ×88.4.
Abbreviations: EM: electron microscopy; GL: glomerular lesions; hpf: high-power field; IF: immunofluorescence; IHC: immunohistochemistry; TBM: tubular basement membranes; TIN: tubulointerstitial nephritis.