Acute kidney injury and mortality in hematopoietic stem cell transplantation: A single-center experience

Leveraging Electronic Health Records to Predict the Risk of Acute Kidney Injury after Allogeneic Hematopoietic Cell Transplantation

BACKGROUND

The objective of this study is to assess the electronic health records (EHRs), which are potential risk factors for acute kidney injury (AKI) after allogenic hematopoietic cell transplantation (allo-HCT), and to propose a basic dataset and score for the calculation of HCT-acute kidney injury risk (HCT-AKIR).

METHODS

We undertook a retrospective analysis of the EHRs of 312 patients. Pre- and post-transplant factors were assessed, recognizing the following structured entries: laboratory data, encounters, medication, imaging studies, diagnoses, and procedures. Composite variables were used to create patient groups by combining two or more multivariate significant risk factors for AKI. The EHRs dataset and HCT-AKIR score were created based on the multivariate analysis of the composite variables.

RESULTS

A multivariate analysis showed that previous CKD and once-impaired pre-transplant kidney function, sepsis, imaging procedures with contrast media, and cumulative length of intensive care unit stay after transplantation were significant risk factors. A new unit-weighted composite score based on the combination of significant risk factors contained in common EHR resources was proposed.

CONCLUSIONS

Using our novel HCT-AKIR score calculated from the basic EHR dataset could be an easy way to increase awareness of post-transplant AKI and provide risk stratification.

AKI treated with kidney replacement therapy in critically Ill allogeneic hematopoietic stem cell transplant recipients

Acute kidney injury (AKI) is a frequent complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT), but few studies have focused on AKI treated with kidney replacement therapy (AKI-KRT), particularly among critically ill patients. We investigated the incidence, risk factors, and 90-day mortality associated with AKI-KRT in 529 critically ill adult allo-HSCT recipients admitted to the ICU within 1-year post-transplant at two academic medical centers between 2011 and 2021. AKI-KRT occurred in 111 of the 529 patients (21.0%). Lower baseline eGFR, veno-occlusive disease, thrombotic microangiopathy, admission to an ICU within 90 days post-transplant, and receipt of invasive mechanical ventilation (IMV), total bilirubin ≥5.0 mg/dl, and arterial pH <7.40 on ICU admission were each associated with a higher risk of AKI-KRT. Of the 111 patients with AKI-KRT, 97 (87.4%) died within 90 days. Ninety-day mortality was 100% in each of the following subgroups: serum albumin ≤2.0 g/dl, total bilirubin ≥7.0 mg/dl, arterial pH ≤7.20, IMV with moderate-to-severe hypoxemia, and ≥3 vasopressors/inotropes at KRT initiation. AKI-KRT was associated with a 6.59-fold higher adjusted 90-day mortality in critically ill allo-HSCT vs. non-transplanted patients. Short-term mortality remains exceptionally high among critically ill allo-HSCT patients with AKI-KRT, highlighting the importance of multidisciplinary discussions prior to KRT initiation.

Association of β₂ microglobulin level and glomerular filtration rate in patients with acute leukemia after hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation is a life-saving therapy in patients suffering from acute leukemia. However, kidney complications developed after performing hematopoietic stem cell transplantation can affect the course and prognosis of the disease in patients with acute leukemia. This study is aimed at assessing the functional status of the kidneys in patients with acute leukemia who have undergone hematopoietic stem cell transplantation. The study has observed a group of patients with acute lymphoblastic leukemia and acute myeloid leukemia who have undergone hematopoietic stem cell transplantation. It has been discovered that β2 microglobulin is a sensitive method of analyzing renal function, with the β2 microglobulin threshold urine level not exceeding 0.3 mg/L. The complex diagnostics of kidney function in hematopoietic stem cell transplantation recipients has given the opportunity to identify the relationship between increased β2 microglobulin levels and decreased glomerular filtration rate. It has been determined that β2 microglobulin is a biomarker of renal disorders. The obtained data have showed that β2 microglobulin can be used as a diagnostic marker of reduced kidney function.

Recent Advances of Acute Kidney Injury in Hematopoietic Cell Transplantation

Acute kidney injury (AKI) is a common complication of allogeneic hematopoietic cell transplantation (allo-HCT) and is associated with non-relapse mortality (NRM) and quality of life (QOL). Multiple factors may contribute to AKI during allo-HCT and are often present at the same time making it difficult to determine the cause of AKI in each patient. Nephrotoxic drugs, infections, thrombotic microangiopathy (TMA), and sinusoidal obstruction syndrome (SOS) are well described causes of AKI during allo-HCT. Acute graft-versus-host disease (aGVHD) is a major complication of allo-HCT that mainly targets the intestines, liver, and skin. However, recent studies suggest aGVHD may also attack the kidney and contribute to AKI following allo-HCT. For example, severe aGVHD is associated with AKI, suggesting a link between the two. In addition, animal models have shown donor immune cell infiltration and increased expression of inflammatory cytokines in recipient kidneys after allo-HCT. Therefore, aGVHD may also target the kidney and contribute to AKI following allo-HCT. Herein, we describe the etiology, diagnosis, risk factors, pathophysiology, prevention, and treatment of renal injury after allo-HCT. In addition, we highlight emerging evidence that aGVHD may contribute to the development of AKI after allo-HCT.

Acute Kidney Injury in the Modern Era of Allogeneic Hematopoietic Stem Cell Transplantation

Background and objectives Acute kidney injury (AKI) is a major complication of allogeneic hematopoietic stem cell transplantation, increasing risk of non-relapse mortality. AKI etiology is often ambiguous due to heterogeneity of conditioning/graft-versus-host disease (GVHD) regimens. To date, GVHD and calcineurin inhibitor effects on AKI are not well defined. We aimed to describe AKI and assess pre/post-hematopoietic transplant risk factors in a large recent cohort. Design, setting, participants, and measurements We performed a single-center retrospective study of 616 allogeneic hematopoietic cell transplant recipients from 2014-2017. We defined AKI and CKD based on KDIGO criteria and estimated GFR using CKD-EPI equation. We assessed AKI pre/post-hematopoietic transplant risk factors using cause-specific Cox regression and association of AKI with CKD outcomes using Chi-squared test. AKI was treated as a time-dependent variable in relation to non-relapse mortality. Results Incidence of AKI by day-100 was 64%. Exposure to tacrolimus and other nephrotoxins conferred a higher risk of AKI, but tacrolimus levels were not associated with severity. Reduced intensity conditioning carried higher AKI risk compared to myeloablative conditioning. Most stage 3 AKIs were due to ischemic acute tubular necrosis and CNI nephrotoxicity. Kidney replacement therapy was initiated in 21/616 (3%) of whom 9/21 (43%) recovered and 5/21 (24%) survived to hospital discharge. T-cell depleted transplants, higher baseline albumin, and non-Hispanic ethnicity were associated with lower risk of AKI. CKD developed in 21% (73/345) of patients after 12 months. Non-relapse mortality was higher in those with AKI (HR 2.77, 95% CI: 1.8-4.27). Conclusions AKI post-hematopoietic cell transplant remains a major concern. Risk of AKI was higher with exposure to CNIs. T cell depleted hematopoietic cell transplants and higher albumin had lower risk of AKI. Forty-three percent of patients requiring KRT recovered kidney function. Prospective studies are needed to further assess modification of these risk factors.

Incidence and mortality of acute kidney injury in patients undergoing hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

While acute kidney injury (AKI) is commonly reported following hematopoietic stem cell transplant (HCT), the incidence and impact of AKI on mortality among patients undergoing HCT are not well described. We conducted this systematic review to assess the incidence and impact of AKI on mortality risk among patients undergoing HCT.

METHODS

Ovid MEDLINE, EMBASE and the Cochrane Databases were searched from database inceptions through August 2019 to identify studies assessing the incidence of AKI and mortality risk among adult patients who developed AKI following HCT. Random-effects and generic inverse variance method of DerSimonian-Laird were used to combine the effect estimates obtained from individual studies.

RESULTS

We included 36 cohort studies with a total of 5144 patients undergoing HCT. Overall, the pooled estimated incidence of AKI and severe AKI (AKI Stage III) were 55.1% (95% confidence interval (CI) 46.6-63.3%) and 8.3% (95% CI 6.0-11.4%), respectively. The pooled estimated incidence of AKI using contemporary AKI definitions (RIFLE, AKIN and KDIGO criteria) was 49.8% (95% CI 41.6-58.1%). There was no significant correlation between study year and the incidence of AKI (P = 0.12) or severe AKI (P = 0.97). The pooled odds ratios of 3-month mortality and 3-year mortality among patients undergoing HCT with AKI were 3.05 (95% CI 2.07-4.49) and 2.23 (95% CI 1.06-4.73), respectively.

CONCLUSION

The incidence of AKI among patients who undergo HCT remains high, and it has not changed over the years despite advances in medicine. AKI after HCT is associated with increased short- and long-term mortality.

Incidence and Risk Factors for Acute and Chronic Kidney Injury after Adult Cord Blood Transplantation

Although cord blood transplantation (CBT) extends allograft access, patient comorbidities, chemoradiation, and nephrotoxic medications all contribute to acute kidney injury (AKI) risk. We analyzed AKI in adult myeloablative CBT recipients who underwent transplantation from 2006 to 2017 for hematologic malignancies using cyclosporine A (CSA)/mycophenolate mofetil immunosuppression. Maximum grades of AKI were calculated using Kidney Disease: Improving Global Outcomes (grade 1, 1.5 to <2-fold; grade 2, 2 to <3-fold; or grade 3, ≥3-fold over baseline) definitions. In total, 153 patients (median 51 years [range, 23-65], 114/153 [75%] acute leukemia, 27/153 [18%] African, 88/153 [58%] cytomegalovirus seropositive, median age-adjusted hematopoietic cell comorbidity index 3 [range, 0-9], median pretransplant albumin 4.0 g/dL [range, 2.6-5.2]) underwent transplantation. The day 100 cumulative incidence of grade 1-3 AKI was 83% (95% confidence interval [CI], 77%-89%) (predominantly grade 2, median onset 40 days, range 0 to 96), and grade 2-3 AKI incidence was 54% (95% CI, 46%-62%) (median onset 43 days, range 0 to 96). Mean CSA level preceding AKI onset was high (360 ng/mL, target range 300-350). In multivariate analysis, African ancestry, addition of haploidentical CD34⁺ cells, low day -7 albumin, critical illness/intensive care admission, and nephrotoxic drug exposure (predominantly CSA and/or foscarnet) were associated with AKI. In a day 100 landmark analysis, 6% of patients with no prior AKI had chronic kidney disease (CKD) at 2 years versus 43% with prior grade 1 and 38% with prior grade 2-3 AKI (overall P= .02). Adult CBT recipients are at significant AKI risk, and AKI is associated with increased risk of CKD. Prevention strategies, early recognition, and prompt intervention are critical to mitigate kidney injury.

Acute Kidney Injury in Pediatric Patients Receiving Allogeneic Hematopoietic Cell Transplantation: Incidence, Risk Factors, and Outcomes

Acute kidney injury (AKI) is a common adverse event after hematopoietic cell transplantation (HCT). AKI is associated with early death or chronic kidney disease among transplant survivors. However, large-scale pediatric studies based on standardized criteria are lacking. We performed a retrospective analysis of 1057 pediatric patients who received allogeneic HCT to evaluate the incidence and risk factors of AKI according to AKI Network criteria within the first 100 days of HCT. We also determined the effect of AKI on patient survival. The 100-day cumulative incidences of all stages of AKI, stage 3 AKI, and AKI requiring renal replacement therapy (RRT) were 68.2% ± 1.4%, 25.0% ± 1.3%, and 7.6% ± .8%, respectively. Overall survival at 1 year was not different between patients without AKI and those with stage 1 or 2 AKI (66.1% versus 73.4% versus 63.9%, respectively) but was significantly different between patients without AKI and patients with stage 3 AKI with or without RRT requirement (66.1% versus 47.3% versus 7.5%, respectively; P < .001). Age, year of transplantation, donor type, sinusoidal obstruction syndrome (SOS), and acute graft-versus-host disease (GVHD) were independent risk factors for stages 1 through 3 AKI. Age, donor, conditioning regimen, number of HCTs, SOS, and acute GVHD were independent risk factors for AKI requiring RRT. Our study revealed that AKI was a prevalent adverse event, and severe stage 3 AKI, which was associated with reduced survival, was common after pediatric allogeneic HCT. All patients receiving allogeneic HCT, especially those with multiple risk factors, require careful renal monitoring according to standardized criteria to minimize nephrotoxic insults.