Competing and Noncompeting Risk Models for Predicting Kidney Allograft Failure.

BACKGROUND: Prognostic models are becoming increasingly relevant in clinical trials as potential surrogate endpoints, and for patient management as clinical decision support tools. However, the impact of competing risks on model performance remains poorly investigated. We aimed to carefully assess the performance of competing risk and noncompeting risk models in the context of kidney transplantation, where allograft failure and death with a functioning graft are two competing outcomes. METHODS: We included 11,046 kidney transplant recipients enrolled in 10 countries. We developed prediction models for long-term kidney graft failure prediction, without accounting (i.e., censoring) and accounting for the competing risk of death with a functioning graft, using Cox, Fine-Gray, and cause-specific Cox regression models. To this aim, we followed a detailed and transparent analytical framework for competing and noncompeting risk modelling, and carefully assessed the models' development, stability, discrimination, calibration, overall fit, clinical utility, and generalizability in external validation cohorts and subpopulations. More than 15 metrics were used to provide an exhaustive assessment of model performance. RESULTS: Among 11,046 recipients in the derivation and validation cohorts, 1,497 (14%) lost their graft and 1,003 (9%) died with a functioning graft after a median follow-up post-risk evaluation of 4.7 years (IQR 2.7-7.0). The cumulative incidence of graft loss was similarly estimated by Kaplan-Meier and Aalen-Johansen methods (17% versus 16% in the derivation cohort). Cox and competing risk models showed similar and stable risk estimates for predicting long-term graft failure (average mean absolute prediction error of 0.0140, 0.0138 and 0.0135 for Cox, Fine-Gray, and cause-specific Cox models, respectively). Discrimination and overall fit were comparable in the validation cohorts, with concordance index ranging from 0.76 to 0.87. Across various subpopulations and clinical scenarios, the models performed well and similarly, although in some high-risk groups (such as donors over 65 years old), the findings suggest a trend towards moderately improved calibration when using a competing risk approach. CONCLUSIONS: Competing and noncompeting risk models performed similarly in predicting long-term kidney graft failure.

Histopathological Features of Time-Zero Kidney Biopsy Are Predictive Factors for Posttransplant Anemia.

INTRODUCTION: Posttransplant anemia (PTA) is a common complication of kidney transplantation, associated with reduced graft survival and higher mortality. We aimed to determine the association of PTA with histopathological characteristics of time-zero allograft biopsy and donor clinical characteristics. METHODS: We conducted a retrospective, observational cohort study that included 587 patients who underwent kidney transplantation in our center. Hemoglobin levels were assessed at 6 and 12 months after transplantation, and anemia was defined according to World Health Organization criteria. The kidney allograft time-zero biopsy has been done in all investigated cases. The evaluated histopathological parameters of the kidney allografts included glomerulosclerosis, arteriolar hyalinosis (AH), vascular fibrous intimal thickening (CV), interstitial fibrosis, tubular atrophy, and interstitial fibrosis and tubular atrophy. The Banff Classification of Allograft Pathology criteria were followed to assess the allograft histopathological changes. RESULTS: The prevalence of anemia was 31.3% at 6 months after transplantation and 23.5% at 12 months. There was an association between 20-50% glomerulosclerosis and PTA in both time points, independently from estimated glomerular filtration rate. AH and interstitial fibrosis were identified as independent risk factors for anemia 6 months after transplantation. CONCLUSION: Histopathological features of time-zero kidney biopsy may be predictors of PTA. Among them, our study recognized 20-50% degree of glomerulosclerosis, AH, and CV as the most significant risk factors for PTA.

ANAL CANCER IN A RENAL TRANSPLANT RECIPIENT: A CASE REPORT AND LITERATURE REVIEW.

Anal carcinoma is a rare tumor in the general population accounting for 1%-2% of all malignancies. Most anal cancers are squamous cell carcinomas. Human papillomavirus and immunosuppression are the main risk factors for developing anal squamous cell carcinoma. Therefore, the incidence rate of anal squamous cell carcinoma is significantly higher in renal transplant recipients than in the general population. We present a patient who developed anal cancer nine years after renal transplantation. Since there was a significant diagnostic delay in our patient, we would like to emphasize the importance of regular screening for anal cancer in renal transplant recipients.

MANAGEMENT OF PROSTATE CANCER IN KIDNEY TRANSPLANT RECIPIENTS.

Kidney transplantation is the treatment of choice in eligible patients with end-stage kidney disease. Prostate cancer (PC) is the second most common cancer in men worldwide. The prevalence of chronic kidney disease worldwide is 13.4%. The management of localized PC in these patients is challenging due to immunosuppressive therapy and pelvic graft localization. High graft and recipient survival rates have resulted in higher numbers of these patients in our everyday practice. A retrospective analysis of male patients who had undergone kidney transplantation at our center between 2002 and 2022 and were diagnosed and treated for PC was performed. We analyzed the incidence, treatment methods, and follow-up of PC patients in this population. A total of 1079 male patients were transplanted. PC was diagnosed in 12 patients (8 after and 4 before transplantation). The incidence of PC was 1.11%. Radical prostatectomy was performed in 11 patients, and one patient was treated with radical radiotherapy. Eleven patients had stable graft function; 1 graftectomy was performed, unrelated to PC. Three patients were indicated for salvage radiotherapy, one is in process for prostate-specific membrane antigen positron emission tomography (PSMA PET CT), and 7 patients are in follow-up and without recurrence. Radical prostatectomy is a safe treatment method for localized PC in kidney transplant recipients, which does not impair graft function and survival.

Diverse molecular causes of unsolved autosomal dominant tubulointerstitial kidney diseases.

Autosomal Dominant Tubulointerstitial Kidney Disease (ADTKD) is caused by mutations in one of at least five genes and leads to kidney failure usually in mid adulthood. Throughout the literature, variable numbers of families have been reported, where no mutation can be found and therefore termed ADTKD-not otherwise specified. Here, we aim to clarify the genetic cause of their diseases in our ADTKD registry. Sequencing for all known ADTKD genes was performed, followed by SNaPshot minisequencing for the dupC (an additional cytosine within a stretch of seven cytosines) mutation of MUC1. A virtual panel containing 560 genes reported in the context of kidney disease (nephrome) and exome sequencing were then analyzed sequentially. Variants were validated and tested for segregation. In 29 of the 45 registry families, mutations in known ADTKD genes were found, mostly in MUC1. Sixteen families could then be termed ADTKD-not otherwise specified, of which nine showed diagnostic variants in the nephrome (four in COL4A5, two in INF2 and one each in COL4A4, PAX2, SALL1 and PKD2). In the other seven families, exome sequencing analysis yielded potential disease associated variants in novel candidate genes for ADTKD; evaluated by database analyses and genome-wide association studies. For the great majority of our ADTKD registry we were able to reach a molecular genetic diagnosis. However, a small number of families are indeed affected by diseases classically described as a glomerular entity. Thus, incomplete clinical phenotyping and atypical clinical presentation may have led to the classification of ADTKD. The identified novel candidate genes by exome sequencing will require further functional validation.

Hospitalization and death after recovery from acute COVID-19 among renal transplant recipients.

INTRODUCTION: Data on post-COVID-19 in renal transplant recipients (RTR) is scarce. We investigated the rate of hospitalizations, reasons for hospital admission, and mortality rate among RTR who survived acute COVID-19. METHODS: A multi-center retrospective observational cohort study measured hospital admission and death to 180 days after acute SARS-CoV-2 infection in 308 adult patients. RESULTS: The median age was 57 years, 64.9% were male. All patients had at least one comorbidity, and 26.3% had diabetes. Data on post-COVID-19 course was available for 267 patients, and 49 of them (15.9%) required hospital treatment after recovery from the acute infection. The most common indications included pneumonia (24.5%) and renal allograft dysfunction (22.4%), 7 (14.3%) had sepsis and 5 (10.2%) had thrombotic events. A median duration of the hospital stay was 12 days. Six patients (2.2%) died due to multiorgan failure, respiratory insufficiency or urosepsis. The strongest predictor for hospitalization after acute COVID-19 was hospitalization for acute SARS-CoV-2 infection, while better allograft function decreased the probability of hospitalization. CONCLUSION: Delayed consequences of acute COVID-19 are highly prevalent and the health care systems should be prepared to respond to the needs of RTR suffering from post-COVID-19 complications.

Risk factors for non-melanoma skin cancer development in renal transplant recipients: a 40 year retrospective study in Croatia.

AIM: To determine the prevalence of non-melanoma skin cancer (NMSC) and disease-specific risk factors in renal transplant recipients (RTRs). METHODS: This retrospective cohort study enrolled 1232 RTRs (736 men) treated in University Hospital Center Zagreb over 40 years. The effect of sex, age at transplantation, geographic residence, dialysis vintage, and the type of immunosuppressive therapy on NMSC occurrence was investigated. RESULTS: The prevalence of NMSC was 6.81%. Overall, 60.7% of patients developed basal cell carcinoma (BCC) and 30.9% of patients developed cutaneous squamous cell carcinoma (cSCC). Only 8.3% developed both tumors. The BCC:cSCC ratio was 1.76:1. The risk for NMSC was 50% higher in men. Patients older than 50 years at transplantation were at greater risk for NMSC development. Residence in an area with higher ultraviolaet radiation (UV) exposure and dialysis vintage before transplantation did not influence NMSC development. Cyclosporine and azathioprine treatment conferred a greater risk for NMSC than tacrolimus or mycophenolate mofetil treatment. CONCLUSION: RTRs are at high risk for NMSC development. Sex, age at transplantation, and type of immunosuppressive therapy play a role in tumor development.

Trajectories of glomerular filtration rate and progression to end stage kidney disease after kidney transplantation.

Although the gold standard of monitoring kidney transplant function relies on glomerular filtration rate (GFR), little is known about GFR trajectories after transplantation, their determinants, and their association with outcomes. To evaluate these parameters we examined kidney transplant recipients receiving care at 15 academic centers. Patients underwent prospective monitoring of estimated GFR (eGFR) measurements, with assessment of clinical, functional, histological and immunological parameters. Additional validation took place in seven randomized controlled trials that included a total of 14,132 patients with 403,497 eGFR measurements. After a median follow-up of 6.5 years, 1,688 patients developed end-stage kidney disease. Using unsupervised latent class mixed models, we identified eight distinct eGFR trajectories. Multinomial regression models identified seven significant determinants of eGFR trajectories including donor age, eGFR, proteinuria, and several significant histological features: graft scarring, graft interstitial inflammation and tubulitis, microcirculation inflammation, and circulating anti-HLA donor specific antibodies. The eGFR trajectories were associated with progression to end stage kidney disease. These trajectories, their determinants and respective associations with end stage kidney disease were similar across cohorts, as well as in diverse clinical scenarios, therapeutic eras and in the seven randomized control trials. Thus, our results provide the basis for a trajectory-based assessment of kidney transplant patients for risk stratification and monitoring.

Histopathologic findings on indication renal allograft biopsies after recovery from acute COVID-19.

Current knowledge on histopathological changes occurring after COVID-19 in transplanted kidneys is limited. Herein, we present renal allograft pathology findings in patients recovered from COVID-19. Six patients underwent indication biopsy, and one required allograft nephrectomy after acute COVID-19. Demographic data, clinical characteristics, and laboratory findings were recorded. The histopathological analysis included light microscopy, immunostaining, and electron microscopy. Five patients were hospitalized for acute COVID-19, and all were diagnosed with imaging-confirmed pneumonia, one requiring mechanical ventilation, and two requiring dialysis. Two patients had mild form. Histopathologic examination of renal allograft specimens revealed collapsing, perihilar, tip-lesion and secondary FSGS in one patient each. One patient had borderline acute cellular rejection, and two had chronic antibody-mediated rejection. Histopathologic changes of glomerular tufts were accompanied by acute tubular injury in four patients. None of our patients had signs of viral inclusions in kidney cells. One patient died and one remained dialysis-dependent after the good initial response to treatment. Patients with collapsing and perihilar FSGS had further progression of their chronic allograft nephropathy still without need for dialysis. In conclusion, diverse kidney pathology may be found in SARS-CoV-2-infected renal transplant patients. It seems that viral infection may affect the immune system with triggering of glomerular diseases, while the acute tubular injury is of multifactorial etiology. Direct viral effect is less likely.

Parotid metastases of cutaneous squamous cell carcinoma in renal transplant recipients: Case series and literature review.

Cutaneous squamous cell skin carcinoma (cSCC) is the most common skin cancer in renal transplant recipients (RTR). Metastatic potential of cSCC is significantly higher in RTR than in the general population. Parotid metastases (PM) of cSCC are rare, but their prognosis is poor. The present study aimed to investigate the frequency and characteristics of PM of cSCC in our renal transplant cohort. Among 1610 patients who received kidney allografts at our institution in the period from January 1999 to December 2019, 84 patients (5.2%) developed at least one cSCC. Three patients were identified to develop PM within 3 to 6 months after the occurrence of primary cSCC. All PM were discovered by clinical examination and in an advanced stage. Two of them died early after the diagnosis of PMs (after 4 months and 1 year, respectively). In conclusion, immunosuppression is one of the major risk factors for the development of cSCC and its metastases. It contributes to the poor survival of patients with PMs of the cSCC. Our experience emphasizes the need for the employment of the radiological tests in patients with primary high-risk cSCC to evaluate nonpalpable lymph node involvement.

Central nervous system infections in renal transplant recipients.

BACKGROUND: The aim of this study is to determine the incidence, etiology, clinical characteristics, and outcomes of renal transplant recipients diagnosed and treated for central nervous system (CNS) infection at our institution. METHODS: We analyzed data from all renal transplant recipients between January 2007 and December 2019 that were diagnosed and treated for CNS infections at our institution. RESULTS: Of 1374 patients who received renal allografts, 13 were diagnosed with CNS infections (9 males), with a mean age of 53.5 years. Patients were diagnosed with CNS infections between 2 months and 11 years after the transplantation. Causative agents included JC virus, Streptococcus pneumoniae, Cryptococcus neoformans, Herpes zoster virus, Mycobacterium tuberculosis, Listeria monocytogenes, and West Nile virus. One patient had concomitant Nocardia and Neisseria infection. Immunosuppression was reduced in all patients. The patient with JC encephalitis and the patient with concomitant Neisseria and Nocardia meningitis died. One patient was returned to dialysis. Other patients recovered with differing levels of neurologic sequelae. CONCLUSION: Central nervous system infections in renal transplant recipients are rare. However, they are associated with significant morbidity and mortality. A high level of awareness is needed: neurological symptoms may be nonspecific and caused by non-infectious conditions related to the underlying disease, or side-effects of immunosuppressive drugs.

Periodontal inflamed surface area in patients on haemodialysis and peritoneal dialysis: a Croatian cross-sectional study.

BACKGROUND: The decision to initiate dialysis treatment via haemodialysis (HD) or peritoneal dialysis (PD) often involves the consideration of complex factors and remains a matter of debate. The purpose of this study was to quantify the inflammatory burden that periodontitis causes in dialysis patients and to examine whether patients on PD and HD differ in terms of the periodontal inflamed surface area (PISA), which can be helpful for selecting the most appropriate dialysis modality. METHODS: A cross-sectional study was performed on 58 consecutive patients on HD and 31 consecutive patients on PD. PISA was calculated using measurements of the clinical attachment level, recession and bleeding on probing. We performed the primary analysis using multivariable robust regression. RESULTS: Patients on PD had a 746 mm2 (93%) lower mean PISA than patients on HD after adjustment for 20 possible confounders, including the duration of dialysis. The type of dialysis was independently correlated with the PISA (semipartial correlation: - 0.50; p = 0.017; false discovery rate < 5%). After adjusting for confounding factors, the correlation between the duration and type of dialysis was not significant (F (2,44) = 0.01; p = 0.994; η2 = 0.00). Differences in the PISA between patients who had undergone dialysis for less than a year, 2-3 years or ≥ 3 years were not significantly different in either of the two dialysis groups. CONCLUSIONS: PISA levels in Croatian patients on dialysis indicate a high need for periodontal treatment. PD is associated with a smaller PISA independent of many sociodemographic, lifestyle, laboratory and clinical factors. The duration of dialysis does not influence PISA levels. TRIAL REGISTRATION: ISRCTN17887630. A clinical study to investigate gum infection in patients undergoing kidney dialysis.

Hypoproteinemia as a factor in assessing malnutrition and predicting survival on hemodialysis.

Series of studies have described malnutrition as one of the main non-traditional risk factors associated with poor prognosis and treatment outcome in patients on hemodialysis (HD). The aims of this study were to evaluate the link between HD treatment quality and the nutritional status and to additionally investigate the association of malnutrition and overall survival. A total of 134 adult out-patients (56.4% male, mean age 60.8 ± 16.15 years) were enrolled in the study. Clinical and laboratory data were obtained from the medical records. Anthropometric measurements were performed prior to HD. Malnutrition-Inflammation Score (MIS) was used as a scoring system representing the severity of protein-energy wasting (PEW). Malnourished patients were significantly older when compared to non-malnourished patients. They had significantly longer dialysis vintage and lower residual diuresis, BMI, serum proteins, and albumins and lean tissue index (LTI). Malnourished patients survived significantly shorter than non-malnourished patients. Hypoproteinemic patients had significantly lower values of serum albumins and LTI and survived shorter than normoproteinemic patients. Only malnourishment and age were associated with higher overall mortality in all groups of patients. By focusing on MIS and serum protein status rather than dialysis-related factors and different treatment techniques, we could accomplish better nutrition status and improved overall outcomes. While anticipating new and more effective measures for preventing malnutrition, our results clearly demonstrate that striving for the highest possible nutrition status should be one of the key strategies in improving the outcomes in this specific group of patients.

IgA-dominant extracapillary proliferative glomerulonephritis following Escherichia coli sepsis in a renal transplant recipient.

Postinfectious glomerulonephritis (PIGN) generally occurs in association with staphylococcal infection. We present the first reported case of IgA-dominant PIGN after Escherichia coli infection in a renal-transplant recipient. A 65-year-old patient with stable allograft function and E. coli urosepsis was treated with ciprofloxacin for 2 weeks with excellent response. One week later he developed proteinuria 16 g/day. Renal biopsy finding revealed IgA-dominant PIGN. He received steroid pulses and intravenous imunoglobulins without effect and had started with hemodialysis.

The Unexpected Effects of L-Carnitine Supplementation on Lipid Metabolism in Hemodialysis Patients.

BACKGROUND/AIMS: There is a growing body of evidence that the long-term hemodialysis (HD) treatment leads to disturbances of carnitine homeostasis but the results of L-carnitine supplementation in HD patients have been conflicting. In the present prospective study, we investigated the effectiveness of intravenous L-carnitine in mitigating dialysis-related protein-energy wasting (PEW) based on pre-treatment albumin levels. METHODS: Fifty patients (46% male, mean age 63±18.28 years, HD vintage 37.5 (7-288) months) received 1 g L-carnitine intravenously at the end of every HD session for 12 months. Clinical data were obtained from the medical records and charts. Intradialytic hypotension periods (defined as a decrease of systolic blood pressure by ≥ 20 mmHg) were recorded. Dietary habits were evaluated using a self-administered questionnaire prior to L-carnitine supplementation. Laboratory parameters were measured prior to the supplementation and controlled in 6-months intervals. Anthropometric measurements were performed prior to HD session, including "dry" body weight and height, body mass index (BMI), and body composition analysis using bioimpedance spectroscopy. Malnutrition-inflammation score (MIS) was used as a scoring system representing the severity of PEW and an indicator of general functional capacity. RESULTS: A significant increase in total cholesterol, predominantly on the account of LDL was found (p=0.005). Simultaneously, HDL decreased (p=0.001) while triglyceride levels remained unchanged. Although the rise in serum prealbumin could be observed, lean tissue index (LTI) decreased and fat tissue index (FTI) increased which resulted in reduction of the LTI/FTI ratio (p=0.002). When divided into two groups according to the pre-treatment albumin values (< 35 g/L or ≥35 g/L), patients from the higher albumin group showed significant increase in prealbumin (p=0.005), and improved MIS (p=0.03). Multivariate regression analysis showed that higher FTI after introduction of L-carnitine led to greater hemodynamic stability (OR 1.709, 95% CI 1.006-2.905, p=0.048). As there was no differences in HD treatment characteristics, primery kidney disease or residual diuresis we could conclude that positive energy balance (with an increase in prealbumin and FTI) eventually led to better hemodynamic stability. CONCLUSION: Our results show significant effects of L-carnitine supplementation on lipid metabolism. Further clinical trials, as well as experimental research are needed to define the role of lipid metabolism in CKD population. Significant benefits of L-carnitine supplementation in patients with better initial serum albumin levels suggest that this therapy should not be restricted to patients with the worst nutritional and overall status.

Multiple Primary Malignancies in Renal Transplant Recipients: a Single Centre Retrospective Cohort Study.

BACKGROUND/AIMS: Renal transplant recipients are exposed to immunosuppressive treatment which may increase the risk for developing malignancies. Limited data exists concerning the occurrence of multiple primary malignancies (MPM) in renal transplant patients. METHODS: All the patients who received a renal allograft at our institution from 1973 to 2017 were included in this investigation. Data from patients with more MPM were obtained from the charts and medical records. Malignancies were categorized as synchronous if the interval between occurrences was less than or equal to 6 months and metachronous if the interval was more than 6 months. RESULTS: Out of the 1884 patients who received a renal allograft, 164 (8.7%) developed a malignant tumor. Twenty-two patients (13.4%; 6 females, 16 males) developed MPM, 7 synchronous (31.8%) and 15 metachronous types (68.2%). The most common initial primary tumors were skin cancers (8) and kidney cancers (3). Furthermore, skin cancers were the most common second primary malignancies (9). Log-rank analysis revealed significantly better survival in the synchronous group (113.3 months) than in the metachronous group (24.6 months) (p=0.04). CONCLUSION: MPM are more frequent in renal transplant recipients than in the general population. It is associated with a high mortality rate, especially in the metachronous group. An increased awareness and frequent screening tests are necessary when managing this condition.

Membrane therapeutic plasma exchange with and without heparin anticoagulation.

BACKGROUND: Administration of an anticoagulant during therapeutic plasma exchange (TPE) is necessary to avoid circuit clotting and impaired treatment effectiveness. Citrate is the preferred anticoagulant for apheresis worldwide, and unfractionated heparin (UH) is the second most preferred, yet there are only a few published studies regarding the use of UH during TPE. There are even fewer studies regarding the use of low-molecular-weight heparin (LMWH) and TPE performed without anticoagulation. MATERIALS AND METHODS: We retrospectively analyzed the database of the Department of Nephrology at Zagreb University Hospital Center from 1982 to 2014 to test the safety of various heparin anticoagulation in TPE. We grouped procedures according to anticoagulation type (UH, LMWH, and no anticoagulation) and compared differences in the use of anticoagulants during our study period, patient populations, replacement fluids, and complications. RESULTS: Complications were recorded during 11.1% of the 9,501 procedures. The incidence of any recorded complication was significantly higher in the LMWH group (21.2%) compared to the group with no anticoagulation (16.3%) and the UH group (9.5%) (P < 0.001). Similarly, the blood clotting in the extracorporeal circuit was most common in the LMWH group (LMWH, 12.0%; no anticoagulation, 6.3%; UH, 2.4%; P < 0.001). Incidents of bleeding complications were very low and occurred during or after 13 TPE sessions (0.1% of all procedures). CONCLUSIONS: Our findings indicate that TPE procedures can be conducted safely with UH and, when necessary, without anticoagulation. The use of LMWH was associated with more complications when compared with use of UH and to TPE done without anticoagulation. Further studies are necessary to study its use during TPE procedures.

Differences in CVVH vs. CVVHDF in the management of sepsis-induced acute kidney injury in critically ill patients.

We hypothesized that patients with sepsis and AKI, especially patients without preserved renal function, and treated with continuous veno-venous hemodiafiltration (CVVHDF), have lower risk for mortality than patients treated with continuous veno-venous hemofiltration (CVVH). Patients were included if they fulfilled the diagnosis of severe sepsis or septic shock, suffered AKI and received continuous renal replacement therapy (CRRT) in intensive care unit. There were 62 patients treated by CVVH and 75 treated by CVVHDF. Mean survival time was longer in CVVHDF group with oliguric/anuric patients than in CVVH group. CVVH, and not classic risk factors, was associated with higher overall mortality in oliguric/anuric patients. In the linear regression model, hourly urine output was the strongest and positive predictor of longer survival. CVVHDF is according to our results a CRRT modality of choice for the treatment and lower mortality of septic patients with AKI where renal function is no longer preserved. CRRT has been associated with improved renal recovery, but it should be started earlier in AKI evolution with still preserved hourly urine output which is the most sensitive and prognostic marker of survival in septic patients with AKI.

A randomized crossover study comparing membrane and centrifugal therapeutic plasma exchange procedures.

BACKGROUND: Therapeutic plasma exchange (TPE) can be performed either on a membrane-based system (mTPE) or on a device that separates blood components by centrifugation (cTPE). The number of studies in this field is limited. This randomized study is the first that offers data on the membrane-based Diapact device (B. Braun Medical, Inc.) for TPE procedures and compares it to the centrifuge-based Spectra Optia (Terumo BCT, Inc.). STUDY DESIGN AND METHODS: Twenty-seven patients were enrolled in this randomized prospective head-to-head study comparing the mTPE and cTPE systems. Procedures on both devices were standardized and the plasma removal efficiency (PRE); total procedure time (including setup and priming time); and removal efficiencies of blood cells, immunoglobulin (Ig)G, and fibrinogen for all procedures were analyzed. RESULTS: While both systems removed similar amounts of plasma, it took the cTPE device a mean of 101.5 ± 24.6 minutes to finalize a procedure that was one-third less than procedures on the mTPE device (157 ± 26.2 min; p < 0.0001), due to a difference in PRE between the Spectra Optia (83.0% ± 4.9%) and the Diapact (53.2% ± 6.6%; p < 0.0001). The difference in removal efficiencies of IgG and blood cells were not significantly different but the Spectra Optia was more efficient in removing the larger fibrinogen protein than the Diapact (72.3% ± 8.5% vs. 62.9% ± 16.1%, respectively; p < 0.02). CONCLUSION: This study shows that, although both systems perform adequate and safe TPE procedures, those on the Spectra Optia in comparison to the Diapact are more efficient in terms of plasma removal and significantly shorter.