Impact of the number of steroid pulses in tonsillectomy combined with steroid pulse therapy: a nationwide retrospective study in Japan

Current treatment status of IgA nephropathy in Japan: a questionnaire survey

BACKGROUND

In 2020, the Committee of Clinical Practical Guideline for IgA Nephropathy (IgAN) revised the clinical practice guidelines. Herein, we conducted a questionnaire survey to assess the potential discrepancies between clinical practice guidelines and real-world practice in Japan.

METHODS

A web-based survey of members of the Japanese Society of Nephrology was conducted between November 15 and December 28, 2021.

RESULTS

A total of 217 members (internal physicians: 203, pediatricians: 14) responded to the questionnaire. Of these respondents, 94.0% answered that the clinical practice guidelines were referred to "always" or "often." Approximately 66.4% respondents answered that histological grade (H-Grade) derived from the "Clinical Guidelines for IgA nephropathy in Japan, 3rd version" and the "Oxford classification" were used for pathological classification. Moreover, 73.7% respondents answered that the risk grade (R-grade) derived from the "Clinical Guidelines for IgA nephropathy in Japan, 3rd version" was referred to for risk stratification. The prescription rate of renin-angiotensin system blockers increased based on urinary protein levels (> 1.0 g/day: 88.6%, 0.5-1.0 g/day: 71.0%, < 0.5 g/day: 25.0%). Similarly, the prescription rate of corticosteroids increased according to proteinuria levels (> 1.0 g/day: 77.8%, 0.5-1.0 g/day: 52.8%, < 0.5 g/day: 11.9%). The respondents emphasized on hematuria when using corticosteroids. In cases of hematuria, the indication rate for corticosteroids was higher than in those without hematuria, even if the urinary protein level was 1 g/gCr or less. Few severe infectious diseases or serious deterioration in glycemic control were reported during corticosteroid use.

CONCLUSION

Our questionnaire survey revealed real-world aspects of IgAN treatment in Japan.

Histological classification of Japanese IgA nephropathy with a small number of glomeruli using Bayes' theorem

In Japan an original pathological classification of IgA nephropathy was used, while Oxford classification of IgA nephropathy was used globally. The Oxford classification requires ≥ 8 glomeruli while the Japanese classification requires ≥ 10. Ninety-nine patients diagnosed with IgA nephropathy were included. To determine the accuracy of histological staging, we calculated the posterior probability using Bayes' theorem and adopted three model of prior distribution. First, the actual staging distribution was reclassified using the beta distribution (reclassified distribution). Second a model with the same distribution (actual distribution) as the actual staging was used. Third, a model assuming that all cases are equally distributed (equal distribution) was used. The median number of collected glomeruli was 12 (8-19). There were 33 cases (33%) wherein the glomerular count was ≤ 9. When only cases with ≥ 10 glomeruli were included, the median posterior probability was 91% (74-99) (actual distribution, 90% [74-98]; equal distribution, 85% [73-96]). Even among the 33 cases with ≤ 9 glomeruli, there were approximately 7 cases in which the posterior probability was ≥ 90% for each model. Using Bayesian probabilistic analysis, it was possible to evaluate the histologic classification of IgA nephropathy, even when the number of obtained glomeruli was ≤ 9.

Evaluation of appropriate treatment for IgA nephropathy with mild proteinuria and normal renal function

BACKGROUND

Tonsillectomy and steroid pulse therapy (TSP) for immunoglobulin A nephropathy (IgAN) is frequently employed in many Japanese institutions; however, performing this invasive treatment in patients with mild IgAN is controversial. This study aimed to evaluate the appropriate treatment for IgAN patients with mild proteinuria.

METHODS

In this retrospective cohort analysis, 122 IgAN patients with mild proteinuria (0.5-1.0 g/day) and estimated glomerular filtration rate of ≥ 60 mL/min/1.73 m² were classified into three groups as follows: patients treated with TSP (n = 32), oral prednisolone (oPSL, n = 33), and conservative therapy (CONS, n = 47). The clinical and histological backgrounds, 5-year remission rates of urinary findings, and 10-year renal survival rates were analyzed.

RESULTS

The backgrounds were similar among the three groups. The remission rates of hematuria, proteinuria, and both were significantly higher for TSP and oPSL than for CONS; however, they were similar for TSP and oPSL. In the multivariate Cox regression analysis, TSP and oPSL were independent factors for the remission of urinary findings compared with CONS; however, the relapse rates of urinary abnormalities were similar among the three groups. No patient progressed to end-stage renal disease (ESRD) within 10 years. Adverse effects of corticosteroid therapy were significantly more frequent in oPSL than in TSP.

CONCLUSION

In IgAN patients with mild proteinuria and stable renal function, similar to oPSL, TSP showed higher remission rates of hematuria and/or proteinuria than CONS, and no case progressed to ESRD regardless of the treatment methods. Therefore, appropriate treatments should be carefully considered for each patient.