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Decreases of proteinuria during alternate-day prednisone therapy in nephrotic syndrome
J F Wetzels1, A J Hoitsma, R A Koene
1Department of Medicine, University Hospital, Nijmegen, The Netherlands.
Abstract:
Treatment of patients with membranous glomerulonephritis with prednisone on alternate days results in a decreased proteinuria on non-prednisone days. We have studied this phenomenon in more detail in 14 patients (11 M, 3 F) with membranous glomerulonephritis. Mean age +/- SD of the patients was 47 +/- 14 years, mean endogenous creatinine clearance 94 +/- 35 ml/min, and median proteinuria 8.8 g/24 h (range 5.0-30.0 g/24 h). Glomerular filtration rate (GFR, inulin clearance), effective renal plasma flow ERPF, PAH clearance), and proteinuria were measured on a control day (C), and six days after the start of alternate-day prednisone treatment, on the third non-prednisone day (NP3, 24-28 h after the last dose of prednisone). Proteinuria decreased from 6.1 mg/min (3.2-9.8 mg/min) (C) to 2.5 mg/min (1.0-7.7 mg/min) at NP3 (median, interquartile range; P less than 0.01), the percentage decrease averaged 45 +/- 8%. The decrease of proteinuria was correlated with baseline GFR (r = 0.75; P less than 0.01). GFR and ERPF did not change significantly, but filtration fraction decreased significantly from 14.5 +/- 0.8% (C) to 13.5 +/- 0.9% (NP3; P less than 0.05). Fractional excretion of albumin, IgG, and transferrin decreased significantly, by -40 +/- 8%, -52 +/- 6%, and -52 +/- 7% respectively. Fractional excretion of beta 2-microglobulin decreased significantly less by -12 +/- 10%. We conclude that proteinuria is decreased on non-prednisone days in patients with membranous glomerulonephritis treated with alternate-day steroids. The observed decrease of filtration fraction suggests that a reduction of glomerular pressure is involved. In addition, the magnitude of the decrease of proteinuria might indicate a change in glomerular permselectivity characteristics.
Insights
Alternate-day prednisone treatment significantly reduces proteinuria in membranous glomerulonephritis patients on non-prednisone days. This suggests reduced glomerular pressure and potential changes in kidney permselectivity.
Area of Science:
- Nephrology
- Pharmacology
- Glomerular Diseases
Background:
- Membranous glomerulonephritis (MGN) is a leading cause of nephrotic syndrome in adults.
- Alternate-day prednisone therapy is sometimes used, but its effect on proteinuria on non-treatment days requires detailed study.
- Understanding the mechanisms behind proteinuria reduction is crucial for optimizing treatment strategies in MGN.
Purpose of the Study:
- To investigate the phenomenon of decreased proteinuria on non-prednisone days in MGN patients receiving alternate-day steroid treatment.
- To explore the impact of this treatment regimen on glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and filtration fraction.
- To analyze changes in the fractional excretion of various proteins to understand the underlying mechanisms of proteinuria reduction.
Main Methods:
- 14 patients with MGN underwent assessment of proteinuria, GFR (inulin clearance), and ERPF (PAH clearance) on a control day and on the third non-prednisone day after initiating alternate-day prednisone.
- Proteinuria was measured in mg/min, and GFR/ERPF were used to calculate filtration fraction.
- Fractional excretion of albumin, IgG, transferrin, and beta 2-microglobulin was quantified.
Main Results:
- Proteinuria significantly decreased by an average of 45% on non-prednisone days (P < 0.01), correlating with baseline GFR (r = 0.75).
- Filtration fraction significantly decreased from 14.5% to 13.5% (P < 0.05), while GFR and ERPF showed no significant changes.
- Fractional excretion of albumin, IgG, and transferrin decreased significantly (-40% to -52%), but beta 2-microglobulin excretion decreased less (-12%).
Conclusions:
- Alternate-day prednisone treatment effectively reduces proteinuria on non-prednisone days in MGN patients.
- The observed decrease in filtration fraction suggests that reduced glomerular pressure plays a role in this effect.
- The differential reduction in protein excretion indicates potential alterations in glomerular permselectivity.