Clinical Rationale for a Routine Testing Schedule Using Donor-Derived Cell-Free DNA After Kidney Transplantation.

Kidney transplant recipients require meticulous clinical and laboratory surveillance to monitor allograft health. Conventional biomarkers, including serum creatinine and proteinuria, are lagging indicators of allograft injury, often rising only after significant and potentially irreversible damage has occurred. Immunosuppressive medication levels can be followed, but their utility is largely limited to guiding dosing changes or assessing adherence. Kidney biopsy, the criterion standard for the diagnosis and characterization of injury, is invasive and thus poorly suited for frequent surveillance. Donor-derived cell-free DNA (dd-cfDNA) is a sensitive, noninvasive, leading indicator of allograft injury, which offers the opportunity for expedited intervention and can improve long-term allograft outcomes. This article describes the clinical rationale for a routine testing schedule utilizing dd-cfDNA surveillance at months 1, 2, 3, 4, 6, 9, and 12 during the first year following kidney transplantation and quarterly thereafter. These time points coincide with major immunologic transition points after transplantation and provide clinicians with molecular information to help inform decision making.

Compartmental Models of the COVID-19 Pandemic for Physicians and Physician-Scientists.

As the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection spreads globally, physicians and physician-scientists are confronted with an enlarging body of literature about the nature of this pandemic. Understanding the current epidemiological models for disease spread, mortality, and recovery is more important than ever before. One of the most relevant mathematical models relating to the spread of a pandemic is the susceptible-infectious-removed (SIR) model. Other models worth exploring are the susceptible-exposed-infectious-removed (SEIR) and the susceptible-unquarantined-quarantined-confirmed (SUQC) model.

Long-Term Follow-Up Evaluation of Renal Function in Patients with Chronic Kidney Disease Undergoing Cardiac Surgery.

Background. Acute kidney injury (AKI) is a common complication of cardiac surgery but its long-term consequences, in patients with chronic kidney disease (CKD), are not known. Methods. We compared the long-term prognoses of CKD patients who developed (n = 23) and did not develop (n = 35) AKI during the period of hospitalization after undergoing coronary artery bypass graft (CABG). Fifty-eight patients who survived (69.6 ± 8.4 years old, 72% males, 83% Whites, 52% diabetics, baseline GFR: 46 ± 16 mL/min) were followed up for 47.8 ± 16.4 months and treated for secondary prevention of events. Results. There were 6 deaths, 4 in the AKI+ and 2 in the AKI- group (Log-rank = 0.218), two attributed to CV causes. At the end of the study, renal function was similar in the two groups. One AKI- patient was started on dialysis. Only 4 patients had an increase in serum creatinine ≥ 0.5 mg/dL during follow-up. Conclusion. CKD patients developing AKI that survived the early perioperative period of coronary intervention present good renal and nonrenal long-term prognosis, compared to patients who did not develop AKI.

Symptom reports are not reliable during ambulatory reflux monitoring.

OBJECTIVES: Patient reporting of symptom events during ambulatory reflux monitoring is commonly performed with little data regarding its accuracy. We employed a novel time-synchronized ambulatory audio recording of symptom events simultaneously with prolonged pH/impedance monitoring to assess temporal accuracy of patient-reported symptoms. METHODS: An acoustic monitoring system was employed to detect cough events via tracheal and chest wall sounds and it was temporally synchronized with an ambulatory impedance/pH monitoring system. Patients were instructed to record their symptoms in the usual manner. Six separate observers independently listened to the 24-h audio recordings and logged the exact timing of each cough event. Patients were blinded to study design and the audio reviewers were blinded to their own reports and those of patients and other reviewers. Concurrence of audio recordings and patient-reported symptoms were tested for three separate time thresholds: 1, 2, and 5 min. RESULTS: The median (interquartile range (IQR)) number of cough events by audio detection was significantly (P<0.001) higher than those reported by patients: 216 (90-275) and 34 (22-60), respectively. There was significantly (P<0.001) higher agreement among the audio recording listeners (substantial to almost perfect agreement; kappa=0.77-0.82) than between the audio recording and patient-reported symptoms (slight to fair agreement; kappa=0.13-0.27). Patients did not report 91, 82, and 71% of audible cough events based on 1-, 2-, and 5-min concordance time windows, respectively. CONCLUSIONS: We found that patients do not report the majority of their symptoms during ambulatory reflux monitoring even within a 5-min time window of the true event and advise caution in clinical decision-making based solely on symptom indices.

Evaluation of patients with suspected laryngopharyngeal reflux: a practical approach.

Laryngopharyngeal reflux (LPR) is associated with symptoms of laryngeal irritation such as throat pain, cough, and voice change. Currently, the two main diagnostic tools are laryngoscopy and reflux monitoring. On laryngoscopy, the signs most commonly used to diagnose LPR are erythema and edema of the larynx; however, these signs are not specific for LPR, may be associated with other causes, and may even be found in healthy individuals. In addition, pH testing has low sensitivity in diagnosing gastroesophageal reflux disease-related laryngeal findings. Proton pump inhibitor (PPI) therapy remains the cornerstone of treatment. The current management recommendation for this group of patients is empiric therapy with twice-daily PPIs for 1 to 2 months. In the majority of those who are unresponsive to such therapy, other causes of laryngeal irritation are considered. Surgical fundoplication is most effective in those who are responsive to acid-suppressive therapy.