Acute kidney injury after allogeneic hematopoietic stem cell transplantation - Predictors and survival impact: A single center retrospective study.

INTRODUCTION AND OBJECTIVES: Acute kidney injury (AKI) is a frequent complication of hematopoietic stem cell transplantation (HSCT) and appears to be linked to increased morbidity and mortality. The aim of this study was to evaluate the incidence, etiology, predictors and survival impact of early AKI in the post-allogeneic HSCT setting. PATIENTS AND METHODS: We performed a retrospective single center study that included 155 allogeneic transplant procedures from June 2017 through September 2019. RESULTS: AKI was observed in 50 patients (32%). In multivariate analysis, age (OR 31.55, 95% CI [3.42; 290.80], p=0.002), evidence of disease at the time of transplant (OR 2.54, 95% CI [1.12; 5.75], p=0.025), cytomegalovirus reactivation (OR 5.77, 95% CI [2.43; 13.72], p<0.001) and hospital stay >35 days (OR 2.66, 95% CI [1.08; 6.52], p=0.033) were independent predictors for AKI. Increasing age (HR 1.02, 95% CI [1.00; 1.04], p=0.029), increasing length of hospital stay (HR 1.02, 95% CI [1.01; 1.03], p=0.002), matched unrelated reduced intensity conditioning HSCT (HR 1.91, 95% CI [1.10; 3.33], p=0.022), occurrence of grade III/IV acute graft-versus-host disease (HR 2.41, 95% CI [1.15; 5.03], p=0.019) and need for mechanical ventilation (HR 3.49, 95% CI [1.54; 7.92], p=0.003) predicted an inferior survival in multivariate analysis. Early AKI from any etiology was not related to worse survival. CONCLUSION: Patients submitted to HSCT are at an increased risk for AKI, which etiology is often multifactorial. Due to AKI incidence, specialized nephrologist consultation as part of the multidisciplinary team might be of benefit.

Validation of blood gas analysis in arteriovenous fistula for hemodialysis.

INTRODUCTION: Arterial blood gas analysis is a minimally invasive technique used in our daily practice but is not a complication free technique. The aim of this study was to validate results from blood gas analysis obtained from the arteriovenous fistula (AVF)/graft as a surrogate marker of the arterial blood gas analysis. METHODS: A prospective observational study was made in 45 patients. We performed arterial and AVF/graft blood gas analysis and results were compared by a paired sample t Student test. RESULTS: Most of our subjects was male (68.9%) and the mean age was 67 years (±14). Hemodialysis vintage was 63 months (±66), and vascular access age was 62 months (±56). The more prevalent vascular access was left radiocephalic AVF (n = 16; 35.6%) and the main puncture artery was right radial artery (n = 27; 60.0%). There were no statistically significant differences between the samples collected. CONCLUSIONS: Our results suggest a possible alternative of arterial blood gas analysis in AVF/graft for hemodialysis patients. This could result in making an uncomfortable procedure almost painless and reducing complications. Future research should take place to include anatomical characteristics of the AVF or the circulation of recirculation.

An Atypical Presentation of Thrombotic Microangiopathy After Lung Transplant: A Case Report.

Thrombotic microangiopathy (TMA) is a pathologic condition characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ injury due to microvascular endothelial lesions and thrombosis. It occurs in a variety of diseases and, unless recognized and treated, leads to severe morbidity and mortality. We present the case of a 48-year-old woman who underwent lung transplantation, initially under tacrolimus, mycophenolate mofetil (MMF), and prednisolone. Several complications emerged in the following months, including abdominal aortic and left renal artery thrombosis and cutaneous infections, although her renal function remained normal. Six months after transplant, her renal function began to deteriorate, which was assumed to be due to elevated tacrolimus levels and doses were adjusted. Due to leukopenia, MMF was changed to everolimus. One year after, she was admitted with fatigue, anemia, and renal dysfunction. Complementary exams revealed only iron deficiency, leukopenia, normal platelets, and elevated lactate dehydrogenase; her renal ultrasound was normal. A renal biopsy was performed and thrombotic microangiopathy was subsequently identified as the main cause of the renal dysfunction. Tacrolimus was therefore discontinued and MMF restarted with slow improvement of renal function. Only when everolimus was stopped did the patient's renal function show incremental improvement. TMA may be a serious complication after lung transplantation and the risk is higher when a combination of tacrolimus and everolimus is used. Renal biopsy findings are essential to confirm the final diagnosis of TMA, allowing for a change in immunosuppression to prevent permanent and severe renal damage.