Table 4.

Histologic findings in renal biopsies of patients with THSD7A-associated MN

Renal Biopsy FindingsTHSD7A-associated MNP Value
No MalignancyMalignancy
Whole cohort144
IgG1-positive biopsies (%)13 (100)a3 (100)a>0.99
IgG4-positive biopsies (%)9 (64)2 (50)0.61
Inflammatory cells per glomerulus, median, interquartile rangeb3.0, 2.0–4.04.5, 2.0–8.250.04
Glomeruli with >8 inflammatory cells per glomerulusb4/105 (3.8)5/20 (25.0)<0.01
Biopsies with glomerular thrombi (%)0 (0)0 (0)>0.99
Biopsies with mesangial deposits (%)3 (21.4)1 (25.0)0.88
Biopsies with subendothelial electron–dense deposits (%)1 (7.1)0 (0.0)0.58
IgM-positive biopsies (%)2 (14.2)0 (0.0)0.42
IgA-positive biopsies (%)2 (14.2)0 (0.0)0.42
Biopsies with minor (<15%) tubulointerstitial fibrosis (%)8 (57.1)3 (75.0)0.52
Biopsies with moderate (16%–49%) tubulointerstitial fibrosis (%)5 (35.7)0 (0.0)0.16
Biopsies with extended (>50%) tubulointerstitial fibrosis (%)1 (7.1)0 (0.0)0.58
Biopsies with stage 1 glomerular lesions according to the work by Ehrenreich and Churg20 (%)4 (28.6)1 (25.0.0)0.89
Biopsies with stage 2 glomerular lesions according to the work by Ehrenreich and Churg20 (%)8 (57.1)2 (50.0)0.80
Biopsies with stage 3 glomerular lesions according to the work by Ehrenreich and Churg20 (%)2 (14.2)0 (0)0.42
Biopsies with stage 4 glomerular lesions according to the work by Ehrenreich and Churg20 (%)0 (0)1 (25.0)0.54
Biopsies with nephrosclerosis (%)4 (28.6)1 (25.0)0.89
Glomeruli per biopsy, median, interquartile range9.5, 6.25–27.59.5, 7.75–120.71
Scarred glomeruli per biopsy specimen, median, interquartile range0.0%, 0.0%–8.76%0.0%, 0.0%–5.56%0.63
  • Interstitial fibrosis was classified as minor, moderate, or extended when ≤15%, >15% but ≤50%, or >50%, respectively, of the tubulointerstitial space was involved.

  • a Analysis of IgG1 could not be performed in two biopsies; in these cases, no more renal tissue was available.

  • b The number of inflammatory cells per glomerulus was analyzed as described in a previous publication.19 Inflammatory cells were counted on 105 glomeruli from renal biopsies of patients with no malignancy and 20 glomeruli from renal biopsies of patients with malignancy.