title: Oral calcitriol for the treatment of persistent proteinuria in immunoglobulin A nephropathy: an uncontrolled trial.
abstract: BACKGROUND
  Laboratory research and previous retrospective study suggest that vitamin D and its analogues have profound effects on immune system function and glomerular mesangial cell proliferation. We conducted an open-label study to evaluate the antiproteinuric effect of calcitriol on proteinuria in patients with immunoglobulin A (IgA) nephropathy.
  
  
  METHODS
  Open-label prospective uncontrolled trial.
  
  
  METHODS
  10 patients (3 men) with biopsy-proven IgA nephropathy and persistent proteinuria despite angiotensin-converting enzyme-inhibitor or angiotensin receptor blocker therapy in a tertiary referral center.
  
  
  METHODS
  Calcitriol, 0.5 microg, twice weekly for 12 weeks.
  
  
  METHODS
  Changes in proteinuria, renal function, serum transforming growth factor beta (TGF-beta) and angiotensin II levels.
  
  
  RESULTS
  After calcitriol treatment, there was a significant overall decrease in proteinuria with time by using a general linear model with repeated measures (P = 0.03). There was a progressive decrease in urine protein-creatinine ratio from 1.98 +/- 0.74 to 1.48 +/- 0.81 g/g (P = 0.007) during the first 6 weeks that persisted throughout the study period. No significant change in blood pressure or renal function was noted. There was a simultaneous decrease in serum TGF-beta level, and percentage of decrease in serum TGF-beta level significantly correlated with percentage of change in proteinuria (Spearman r = 0.643; P = 0.02). Serum angiotensin II level did not change throughout the study. One patient experienced transient hypercalcemia that normalized after a dosage decrease. No other major adverse effect was reported.
  
  
  CONCLUSIONS
  This small study is uncontrolled and does not examine the long-term effect of calcitriol therapy.
  
  
  CONCLUSIONS
  Twice-weekly oral calcitriol has a modest antiproteinuric effect in patients with IgA nephropathy and persistent proteinuria despite angiotensin-converting enzyme-inhibitor or angiotensin receptor blocker therapy. Additional studies are needed to confirm the renal protecting effect of calcitriol in patients with chronic proteinuric kidney diseases.
authors.affiliation: Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China. ccszeto@cuhk.edu.hk
authors.forename: Cheuk-Chun
authors.initials: CC
authors.lastname: Szeto
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chow
authors.forename: Bonnie Ching-Ha
authors.initials: BC
authors.lastname: Kwan
authors.forename: Kwok-Yi
authors.initials: KY
authors.lastname: Chung
authors.forename: Chi-Bon
authors.initials: CB
authors.lastname: Leung
authors.forename: Philip Kam-Tao
authors.initials: PK
authors.lastname: Li
mesh_terms: D000284:Administration, Oral; D000328:Adult; D002117:Calcitriol / Q000008:administration & dosage*; D005260:Female; D005922:Glomerulonephritis, IGA / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011507:Proteinuria / Q000188:drug therapy* / Q000209:etiology; D012076:Renal Agents / Q000008:administration & dosage*
chemical_list: D012076:Renal Agents; D002117:Calcitriol