Tonsillectomy in a European Cohort of 1,147 Patients with IgA Nephropathy

Abstract

Background: Tonsillectomy has been considered a treatment for IgA nephropathy (IgAN). It is aimed at removing a source of pathogens, reducing mucosa-associated lymphoid tissue and decreasing polymeric IgA synthesis. However, its beneficial effect is still controversial. In Asia, favorable outcomes have been claimed mostly in association with corticosteroids. In Europe, small, single-center uncontrolled studies have failed to show benefits. Methods: The European validation study of the Oxford classification of IgAN (VALIGA) collected data from 1,147 patients with IgAN over a follow-up of 4.7 years. We investigated the outcome of progression to end-stage renal disease (ESRD) and/or 50% loss of estimated glomerular filtration rate (eGFR) and the annual loss of eGFR in 61 patients who had had tonsillectomy. Results: Using the propensity score, which is a logistic regression model, we paired 41 patients with tonsillectomy and 41 without tonsillectomy with similar risk of progression (gender, age, race, mean blood pressure, proteinuria, eGFR at renal biopsy, previous treatments and Oxford MEST scores). No significant difference was found in the outcome. Moreover, we performed an additional propensity score pairing 17 patients who underwent tonsillectomy after the diagnosis of IgAN and 51 without tonsillectomy with similar risk of progression at renal biopsy and subsequent treatments. No significant difference was found in changes in proteinuria, or in the renal end point of 50% reduction in GFR and/or ESRD, or in the annual loss of eGFR. Conclusion: In the large VALIGA cohort of European subjects with IgAN, no significant correlation was found between tonsillectomy and renal function decline.

The mucosa–kidney axis in IgA nephropathy

“…Tonsillectomy combined with steroid pulse therapy induced a 10% greater decrease in proteinuria than steroid pulse therapy alone, but this decrease was of marginal statistical significance, and whether it would lead to a subsequent beneficial effect on renal function is unclear. Consistent with the Japanese trial, a comparison of tonsillectomized patients with IgAN and non-operated matched controls with IgAN assessed in a study performed by the European VALIGA network failed to show any effects of tonsillectomy on circulating markers of innate immunity, ubiquitin-proteasome pathways and the pro-oxidative milieu 87 , or on clinical outcome 88 .…”

Glucocorticoids Reduce Aberrant O-Glycosylation of IgA1 in IgA Nephropathy Patients

“…We are aware of limited potential for generalization of conclusions made from our study cohort but it needs to be highlighted that not only the size of the cohort but also the racial and regional factors could influence the clinical value of measured parameters. For example, tonsilectomy performed in cohort of 200 Japanese IgAN patients [38] showed beneficial effect on IgAN course but this was not proven in European cohort of 61 tonsillectomized IgAN subjects selected from large cohort of 1, 147 VALIGA subjects [39]. …”

The size of palatine tonsils cannot be used to decide the indication of tonsillectomy for IgA nephropathy

“…Although the report by Chen et al [28], with a follow-up period of 11 years, showed a negative result, they mentioned in their discussion section that ‘perhaps a longer follow-up might reveal a statistical significant difference’. Recently, Feehally et al [29] reported that no significant correlation was found between tonsillectomy and a decline in renal function over a follow-up of 4.7 years in the VALIGA cohort. On the basis of the previous reports, a longer follow-up may be needed for a more proper evaluation.…”