Background: Indinavir therapy is associated with a continuum of crystal-related syndromes, including nephrolithiasis, renal colic, flank pain without recognizable stone formation, dysuria and asymptomatic crystalluria. A frank nephropathy has been recognized recently as part of the spectrum.
Methods: A retrospective analysis of 72 HIV-infected individuals receiving indinavir was performed to identify the frequency and risk factors for indinavir-associated nephropathy and urinary complications. Individuals treated with nucleoside analogues alone served as controls.
Results: Mean serum creatinine levels rose from 1.03 +/- 0.16 mg/dl to 1.11 +/- 0.22 mg/dl at week 12 and 1.15 +/- 0.27 mg/dl at week 24 (both, p < 0.01). Thirteen individuals developed serum creatinine levels > or =1.4 mg/dl. Increased serum creatinine levels were found more frequently in women (p < 0.01) and were associated with pyuria and microhematuria (p < 0.01). Frank renal colic and/or nephrolithiasis (seven patients) and urinary pH were not associated with serum creatinine levels > or =1.4 mg/dl. The mean duration of indinavir treatment, until sterile pyuria occurred, were 22 weeks and 32 weeks until the first rise of serum creatinine levels to > or =1.4 mg/dl. Ten patients showed both findings, pyuria preceded the first rise in serum creatinine levels to > or = 1.4 mg/dl (18 vs. 27 weeks, p = 0.02). Renal biopsy, done in three patients, revealed tubulointerstitial disease with crystals in collecting ducts. In 21 patients, among them 11 with pyuria, indinavir was replaced for various reasons and pyuria disappeared in nine. In these patients mean serum creatinine levels decreased from 1.43 mg/dl at withdrawal of indinavir to 1.04 mg/dl three months later (p < 0.01).
Conclusion: Indinavir therapy is associated with a decrease in renal function which is reversible after withdrawal. In addition, indinavir-associated tubulointerstitial disease does no in patients taking indinavir may help to identify patients being at risk for nephrotoxicity.