Corey, Rebecca L

AbstractDrug screening during pre-transplant evaluations can have major implications for patient care, particularly because drug abuse has been associated with poor transplant outcomes. Although urine drug screening is usually preferred, serum testing is available for situations such as anuria due to end stage renal disease. However, there are few studies evaluating serum drug screening in specific populations such as patients undergoing kidney transplant evaluation. All serum drug screens ordered between January 2015 and November 2017 on patients being evaluated for renal transplant were compared against a large population of serum drug screens ordered from other institutions. Cocaine screening and confirmation results were evaluated to determine false positives. Cocaine screens were positive in 23 of 537 (4.3%) pre-transplant samples, and 211 of 5,115 (4.1%) comparison samples. Confirmation testing demonstrated that 14 (60.9%) pre-transplant samples were false positives, which was significantly (P < 0.01) higher than the rate of false positives in the comparison group (47/211, 22.3%). No common medication or other cross-reacting substance could be identified in the pre-transplant cohort to explain the false-positive results. Although serum cocaine screening had a low overall false-positive rate, the proportion of false positives was significantly higher in pre-transplant patients. Given the poor transplant outcomes associated with drug abuse, failure to properly interpret screening results as being false positives could negatively affect patient care. All members of the transplant team should recognize the importance of confirmation testing in this setting, to avoid unintended consequences due to false-positive screening results.

AbstractVitamin D deficiency is common among patients with end‐stage liver disease (ESLD). The primary aim of our study was to assess the prevalence of vitamin D deficiency, secondary hyperparathyroidism, and bone disease in patients with ESLD awaiting LT.MethodsWe retrospectively studied 190 patients at our center. Serum total 25‐hydroxyvitamin D (25‐OH D), parathyroid hormone (PTH), calcium, and bone mineral analysis (BMA) were recorded. Standard World Health Organization (WHO) criteria were used to diagnose osteopenia/osteoporosis. Only patients with normal serum creatinine were analyzed.ResultsThirty‐two of 190 patients were excluded from the final analysis (missing serum total 25‐OH D levels in three patients and elevated serum creatinine, 29 patients). 105 of 158 (66.4%) evaluable patients had 25‐OH D levels <25 ng/mL. Patients included in the analysis (n = 158) were divided according to serum total 25‐OH D levels: 0–10 ng/mL (n = 23), 11–20 ng/mL (n = 64), and >20 ng/mL (n = 71). There were no significant differences in mean serum PTH and corrected calcium levels among the three subgroups. Only three patients had elevated serum PTH. Patients with total 25‐OH D ≤ 10 ng/mL had higher model for end‐stage liver disease (MELD) scores vs. those with 25‐OH D > 20 ng/mL (13.3 ± 3, range 8–21, vs. 11.9 ± 3.4, range 6–29, p = 0.004). Irrespective of vitamin D status, bone disease was present in 64.6% of patients.ConclusionLow vitamin D levels and bone disease are common among patients with ESLD awaiting LT. Despite a high prevalence of low serum total 25‐OH D, our cohort maintained normal corrected calcium levels and did not develop secondary hyperparathyroidism. We propose that free serum 25‐OH D and vitamin D‐binding protein may be necessary to accurately establish the diagnosis of vitamin D deficiency in the setting of ESLD. Additional studies are needed to further define mechanisms of bone disease in patients with ESLD.