Publications

BACKGROUND

Acute kidney injury (AKI), which is common among HIV-positive individuals, may contribute to the excess burden of chronic kidney disease (CKD) in this patient population; however, conventional clinical methods to detect AKI do not capture kidney injury sufficiently early to prevent irreversible damage. Further, large observational and interventional studies of AKI generally exclude HIV-positive persons in spite of their disproportionate risk.

METHODS

The Predictors of Acute Renal Injury Study (PARIS) is a prospective observational cohort study among HIV-positive individuals established to determine the ability of candidate kidney injury biomarkers to predict future hospitalized clinical AKI, to characterize hospitalized subclinical AKI, and to discern the risk of progressive kidney disease following subclinical and clinical AKI. Among the candidate kidney injury markers, we will select the most promising to translate into a clinically viable, multiplex panel of urinary biomarkers which we will integrate with clinical factors to develop a model prognostic of risks for AKI and subsequent kidney function decline. This study has a targeted enrollment of 2000 participants. The overall follow-up of participants consists of two phases: 1) a 5-year active follow-up phase which involves serial evaluations at enrollment, annual clinic visits, and among participants who are hospitalized during this period, an evaluation at index hospitalization and 3 and 12 months post-hospitalization; and 2) a subsequent passive follow-up phase for the duration that the participant receives medical care at The Johns Hopkins Hospital.

DISCUSSIONS

This study will serve as an important resource for future studies of AKI by establishing a repository with both ambulatory and inpatient biospecimens, a resource that is currently lacking in existing HIV clinical cohorts and studies of AKI. Upon completion of this study, the resulting prognostic model which will incorporate results from the multiplex HIV-AKI Risk Pane could serve as a pharmacodynamic endpoint for early phase therapeutic candidates for AKI.

Vitamin D may play an important role in a range of disease processes. In the general population, lower vitamin D levels have been associated with kidney dysfunction. HIV-infected populations have a higher risk of chronic kidney disease. Few studies have examined the link between lower vitamin D levels and kidney function decline among HIV-infected persons. We investigated the associations of serum 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)D] with kidney function decline in a cohort of HIV-infected white and black men under highly active antiretroviral therapy treatment in the vitamin D ancillary study of the Multicenter AIDS Cohort Study. The associations of 25(OH)D and 1,25(OH)D with annual change in estimated glomerular filtration rate (eGFR) were evaluated using linear mixed effects models. This study included 187 whites and 86 blacks with vitamin D measures and eGFR ≥60 ml/min/1.73 m at baseline. Over a median follow-up of 8.0 years, lower 25(OH)D levels were significantly associated with faster eGFR decline in whites (adjusted annual change in eGFR, tertile 1: -2.06 ml/min/1.73 m vs. tertile 3: -1.23 ml/min/1.73 m, p trend .03), while no significant association was detected in blacks. Lower 1,25(OH)D was associated with faster kidney function decline in both whites and blacks, although the estimates were not statistically significant. In conclusion, lower 25(OH)D levels were significantly associated with faster eGFR decline in a cohort of HIV-infected white men, but not in those with black ancestry. Further research is warranted to investigate the association of 25(OH)D and 1,25(OH)D with kidney function decline in larger and ethnically diverse populations.

BACKGROUND AND AIMS

Inadequate polypectomy leads to incomplete resection, interval colorectal cancer, and adverse events. However, polypectomy competency is rarely reported, and quality metrics are lacking. The primary aims of this study were to assess polypectomy competency among a cohort of gastroenterologists and to measure the correlation between polypectomy competency and established colonoscopy quality metrics (adenoma detection rate and withdrawal time).

METHODS

We conducted a prospective observational study to assess polypectomy competency among 13 high-volume screening colonoscopists at an academic medical center. Over 6 weeks, we made video recordings of ≥28 colonoscopies per colonoscopist and randomly selected 10 polypectomies per colonoscopist for evaluation. Two raters graded the polypectomies by using the Direct Observation of Polypectomy Skills, a polypectomy competency assessment tool, which assesses individual polypectomy skills and overall competency.

RESULTS

We evaluated 130 polypectomies. A total of 83 polypectomies (64%) were rated as competent, which was more likely for diminutive (70%) than small and/or large polyps (50%, P = .03). Overall Direct Observation of Polypectomy Skills competency scores varied significantly among colonoscopists (P = .001), with overall polypectomy competency rates ranging between 30% and 90%. Individual skills scores, such as accurately directing the snare over the lesion (P = .02) and trapping an appropriate amount of tissue within the snare (P = .001) varied significantly between colonoscopists. Polypectomy competency rates did not significantly correlate with the adenoma detection rate (r = 0.4; P = .2) or withdrawal time (r = 0.2; P = .5).

CONCLUSIONS

Polypectomy competency varies significantly among colonoscopists and does not sufficiently correlate with established quality metrics. Given the clinical implications of suboptimal polypectomy, efforts to educate colonoscopists in polypectomy techniques and develop a metric of polypectomy quality are needed.