COVID-19 in kidney transplant recipients: Experience from a large health system in Louisiana

Background: Infections are an important cause of morbidity and mortality among kidney transplant recipients. The novel Coronavirus Disease 2019 (COVID-19) has affected all kinds of populations world-wide. However, the role of immunosuppression in the outcomes of these patients is not well understood. Methods: We conducted a retrospective study in kidney transplant recipients from a single health system that were diagnosed with COVID-19 based on a positive real-time reverse transcription polymerase chain reaction test for SARS-CoV-2 RNA between 03/01/2020 and 04/30/2020. We compared them with affected patients without a kidney transplant and without any kind of immunosuppressive medication (control). We examined the rates of hospitalization, intensive-care unit (ICU) admission, acute kidney injury (AKI) and mortality as outcome measures. Results: A total of 8473 patients were diagnosed with COVID-19 within our Health System within the study period. Thirty-three (0.4%) were kidney transplant recipients. Sixteen of the 33 (48%) were admitted to the hospital (median age of 56, 68% males, 93% African American) vs 2201 admissions (25%) for the control group (median age 66, 48% males, 65% African-American), i.e., a significantly greater risk for hospitalization for transplant recipients (p = 0.002). Percentage of patients with hypertension in the transplant group was numerically higher (93% vs 80%, p = 0.06), as well as the number of ICU admissions (43% vs 28%, p = 0.055). AKI was more common in transplant patients (81% vs 33.8% p<0.0001). No difference in mortality was observed (31 vs 24%, p = 0.34). Among transplant patients, those hospitalized were more likely to be on prednisone (75% vs 35%, p = 0.025) and had a post-transplant graft life of 7.9 years compared to 5.5 years for those not hospitalized, p 0.08). Conclusions: Kidney transplant recipients affected with COVID-19 exhibited a greater incidence of hospitalization, AKI and a trend for more ICU admissions. Use of immunosuppression with prednisone was associated with greater risk for hospitalization.

Markers of inflammation and risk for AKI and need for dialysis in patients with COVID-19

Background: Acute kidney injury (AKI) is a reported manifestation of COVID-19 (CoV-AKI). Release of inflammatory cytokines has been recognized as a characteristic feature of COVID-19 and is linked to severity of illness. However, it has not been clearly determined if levels of serum markers of inflammation are associated with risk for development of AKI or its severity. Methods: We conducted an observational study in patients hospitalized at Ochsner Medical Center over 1-month period with COVID-19 and diagnosis of AKI. We examined the relationship between the blood level of ferritin, C-reactive protein (CRP), procalcitonin (proCal), D-dimer and lactate dehydrogenase (LDH) and the incidence of AKI, as well as AKI requiring renal replacement therapy (AKI-RRT), by assessing comparison of means and proportions and by logistic regression analysis. Results: Among 644 patients with COVID-19, we compared 161 (26%) with AKI vs 414 (64%) without AKI. Median serum creatinine on admission was higher in the AKI group (1.8 vs 1.1 mg/dL, p<0.0001). Preexisting chronic kidney disease rates were comparable (35% vs 28%, for AKI and no AKI groups). The median value of inflammatory markers on admission were higher in the AKI group [ferritin 1016 (516-2534) vs 680 (315-1416) ng/mL, p<0.0001;CRP 163 (93-243) vs 93 (46-165) mg/L, p<0.0001;proCal 0.37 (0.2-1.6) vs 0.12 (0.06-0.32) ng/mL, p<0.0001;D-dimer 1.57 (0.96-5.14) vs 1.13(0.68-2.57) mcg/mL, p=0.0004;and LDH 532 (365-804) vs 428 (309-548), p=0.0004]. On multivariate logistic regression analysis, CRP (p=0.003) and ferritin (p<0.035) were associated with greater risk for AKI. In addition, ferritin ≥ 1200 ng/mL and CRP ≥ 300 mg/L were independently associated with AKI [adjusted odds ratio: 2.3 (1.3-4), p=0.003, and 2.5 (1.0-6.3), p=0.05;respectively]. Furthermore, ferritin, CRP, proCal and LDH levels were significantly higher in those with AKI-RRT compared to those not requiring RRT (p=0.022 to p=0.009). Conclusions: Higher level of inflammatory markers were associated with CoV-AKI, and levels were even higher for those with CoV-AKI-RRT. In patients with COVID-19, magnitude of ferritin and CRP on admission could be used for AKI risk stratification.

Phenotype and outcomes of AKI associated with COVID-19 in urban New Orleans

Background: Acute kidney injury (AKI) is a manifestation of COVID-19 (CoVAKI). However, there is paucity of data from United States, particularly in a predominantly African American (AA) population. We report the phenotype and outcomes of AKI at an academic hospital in New Orleans. Methods: We conducted an observational study in patients hospitalized at Ochsner Medical Center over 1-month period with COVID-19 and diagnosis of AKI by KDIGO. We examined the rates of renal replacement therapy (RRT) and in-hospital mortality as outcome measures. Adjudication of cause of AKI was independently performed via manual chart review by 3 study team members. Results: Of 644 admissions with COVID-19, 69 were excluded due to ESRD or kidney transplant. Thus, 575 patients entered the cohort [173 (28%) to an intensive care unit (ICU)]. Patients were predominantly AA (71%). AKI was diagnosed in 161 patients (28% overall, 61% of ICU admissions), median age 65 (34 - 96), predominantly male (62%) and hypertensive (83%). Median follow up was 25 (1 - 45) days. Vasopressors and/or mechanical ventilation was required in 105 (65%) of them. In-hospital mortality rate for those with AKI was 50% (80/181). De novo AKI was diagnosed in 65%, whereas AKI over preexisting chronic kidney disease occurred in 35% of the cohort. Ninetyone (57%) patients arrived with AKI, whereas the remaining 43% acquired AKI during the hospitalization [median hospital day of AKI onset: 4 (2 - 10)]. RRT was required in 89/161 (55%) and 77/105 (73%) patients for all AKI cases and the ICU subset, respectively. The mortality rate for those with AKI-RRT was 72% (64/89). Hemodynamic instability leading to ischemic acute tubular injury (ATI) and rhabdomyolysis accounted for 66% and 7% of the etiology, respectively. Reversible prerenal azotemia occurred in 9%. In 13%, no obvious cause of AKI was identified aside from the COVID-19 diagnosis. Three (1.8%) patients had De novo collapsing glomerulopathy. Conclusions: CoV-AKI is associated with high rates of RRT, ICU care and death. Hemodynamic instability leading to ischemic ATI is the predominant cause of AKI in this setting, but other etiologies contribute to the overall AKI burden.

Morbid obesity, hypertension, and male sex are associated with greater risk for AKI in patients with COVID-19

Background: Acute kidney injury (AKI) is a reported manifestation of COVID-19 (CoV-AKI). However, there is paucity of data regarding risk factors for CoV-AKI. We examined the association of demographics and comorbidities with CoV-AKI risk and its severity at an academic hospital in New Orleans. Methods: We conducted an observational study in patients hospitalized at Ochsner Medical Center over 1-month period with COVID-19 and diagnosis of AKI. We assessed the relationship between baseline demographic and clinical characteristics and the incidence of AKI, as well as AKI requiring renal replacement therapy (AKI-RRT), by assessing comparison of means and proportions and by logistic regression analysis. Results: Among 644 patients with COVID-19, we compared 161 (26%) with AKI vs 414 (64%) without AKI. Male sex (62% vs 51%, p=0.02) and essential hypertension (HTN) (83% vs 70%, p=0.002) were more common in the AKI group. Median body mass index (BMI) was higher among those with AKI (34 vs 31 kg/m2, p<0.0001). No difference was found in age, race, presence of diabetes, chronic kidney disease or heart disease respect to AKI rate. On multivariate logistic regression analysis, HTN was strongly associated with greater risk for AKI [OR 1.96 (CI 1.2-3.2), p=0.009]. Male sex [OR 1.72 (CI 1.1-1.9), p=0.005] and higher BMI [OR 1.04 (CI 1.02-1.07), p<0.001] were also associated with AKI. RRT was required in 89 (55%) of the patients with AKI. Those with AKI requiring RRT (AKI-RRT) had higher median BMI (35 vs 33 kg/m2, p=0.048) and younger age (61 vs. 68, p=0.0003) compared to those with AKI not requiring RRT. Of note, higher BMI correlated with younger age (R=-0.53, p<0.0001). Conclusions: HTN, male sex and higher BMI were associated with greater incidence of AKI in patients hospitalized with COVID-19. Higher BMI was further associated with AKI-RRT. Hypertensive, male and obese patients are at higher risk for CoV-AKI and should be more closely monitored during the COVID-19 pandemic.