Absence of Mesangial C1q Deposition Is Associated with Resolution of Proteinuria and Hematuria after Tonsillectomy Plus Steroid Pulse Therapy for Immunoglobulin A Nephropathy

Abstract

Introduction and Aims: Deposition of C1q occurs in 0 to 45% of patients with IgAN. In order to identify whether mesangial C1q deposition in IgAN is a novel marker for the response to tonsillectomy plus steroid pulse therapy (TSP), we studied the association between mesangial C1q deposition in IgAN and the remission rate after TSP therapy for IgAN. Methods: We conducted a retrospective cohort study at a single Japanese center. We analyzed data on 110 patients diagnosed with IgA nephropathy who received TSP between January 2003 and December 2012. Positive C1q findings were defined as diffuse mesangial C1q deposition. The study outcome was the resolution of abnormal urinary findings and was defined as negative proteinuria and negative occult blood 1 year after steroid pulse therapy. Results: In all enrolled cases, 69 patients (62.7%) went into remission. Ten out of 24 (41.7%) C1q-positive patients experienced remission, and 59 out of 86 (68.6%) C1q-negative patients experienced remission. Multiple logistic regression model analysis showed that the absence of C1q deposition increased the odds ratio for remission (odds ratio 4.41; 95% confidence interval 1.33-15.75, p = 0.017). Conclusions: These results suggest that the absence of diffuse C1q deposition in the mesangial area of the glomerulus in patients with IgA nephropathy is a positive predictive sign for a response to TSP and is associated with the resolution of urinary abnormalities 1 year after TSP.

A multicenter, prospective, observational study to determine association of mesangial C1q deposition with renal outcomes in IgA nephropathy

“…Thus, further research is needed to explore the utility of C1q as a diagnostic or prognostic tool in IgAN patients. C1q deposition rates vary in IgAN patients [11][12][13][14][15][16] , and possible explanations for the discrepancies among studies may be related to differences in race, age, gender ratio, urine protein and methods of analysis.…”

Graft failure of IgA nephropathy in renal allografts following living donor transplantation: predictive factor analysis of 102 biopsies

“…Traditionally, the presence of C1q staining is viewed as a typical pathological lesion of LN rather than IgA N[13]. However, a more recent stud y[32, 33] confirmed that this parameter played a role and occurred in 0 to 45% of patients with IgAN. Lee et al .…”

“…We demonstrated that this parameter exhibited a higher predictive value in IgAN after transplantation. The absence of C1q deposition is a positive predictive sign as a response to steroid pulse therapy and relief of proteinuri a[33]. Therefore, steroid-resistance nephrotic syndrome and a poorer outcome should be taken seriously when C1q staining presents during long-term immunosuppression.…”

Graft failure of IgA nephropathy in renal allografts following living donor transplantation: predictive factor analysis of 102 biopsies

“…Traditionally, the presence of C1q staining is viewed as a typical pathological lesion of LN rather than IgAN [13] . However, a more recent study [32,33] confirmed that this parameter played a role and occurred in 0 to 45% of patients with IgAN. Lee et al [32] concluded that mesangial C1q deposition in the glomerulus was associated with a poor renal outcome and severe pathological features in native IgAN.…”

“…We demonstrated that this parameter exhibited a higher predictive value in IgAN after transplantation. The absence of C1q deposition is a positive predictive sign as a response to steroid pulse therapy and relief of proteinuria [33] . Therefore, steroid-resistance nephrotic syndrome and a poorer outcome should be taken seriously when C1q staining presents during long-term immunosuppression.…”