ABSTRACT
The prevalence of chronic pain among adults in the United States now exceeds 20% and is even higher
among older adults and those with multiple comorbid conditions. As clinicians have increasingly learned to
avoid opiates for chronic pain, non-steroidal anti-inflammatory drugs (NSAIDs) have an essential role as
effective analgesics. Unfortunately, the threat of kidney toxicity from NSAIDs limits their use for pain control,
and there are no options available to mitigate that risk during treatment. As a result, clinicians largely avoid
using NSAIDs in persons who either have chronic kidney disease (CKD) or are at high risk for developing
CKD, regardless of their severity of pain. The premise of this proposal is that NSAID effects on the kidneys can
be monitored through a biomarker guided strategy, and that nephrotoxicity can be detected early among the
subset who would experience deleterious impact on their kidneys. The primary objective of this proposal will be
to build an NSAID Kidney Monitoring Panel from urine and blood biomarkers of kidney tubule health that will
identify the specific sites of NSAID toxicity, distinguish NSAID-induced changes on the kidney, and forecast the
impact on subsequent kidney function declines.
Current monitoring for NSAID-related kidney toxicity still relies on serum creatinine (SCr), which is
insensitive for early detection, lacks specificity for true kidney injury, and does not measure tubulointerstitial
health, the major site of NSAID action and injury. Without a better strategy, clinicians will continue withholding
NSAIDs from patients in chronic pain. Our research team has experience in deploying a broad panel of urine
and blood biomarkers of kidney tubular function, injury and tubulointerstitial inflammation that enables both the
sensitivity to detect early kidney damage and the specificity to distinguish patterns that are most consistent
with a distinct medication effect. We will apply this strategy among two populations at high risk for developing
NSAID nephrotoxicity. To best characterize the impact of high-dose NSAID use, we will evaluate the UCSF
Axial Spondyloarthritis Cohort (Aim 1), as patients with this condition have few other treatment options and are
also largely free of other kidney risk factors. Second, we will collaborate with the Chronic Renal Insufficiency
Cohort (CRIC) to determine the effects of NSAID initiation and discontinuation on kidney health in this very
high-risk group with moderate-to-severe CKD (Aim 2). In Aim 3, we will integrate the findings from each setting
to determine the set of biomarkers that best captures chronic NSAID exposure, dynamic changes in
longitudinal NSAID use, and risks for longitudinal kidney function trajectories.
This research will unquestionably yield tremendous insights into the incidence and patterns of kidney
tubulointerstitial injury from NSAID use in these two distinct populations. We are optimistic that our findings will
guide future development of an NSAID Kidney Monitoring Panel that will improve the safe and effective
treatment of pain across the spectrum of kidney disease risk.