Effect of pre-transplantation use of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in kidney transplant recipients-propensity score-matched analysis.

BACKGROUND: Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEi/ARBs) can cause acute kidney injury under dehydratation or in hemodynamically unstable conditions. Regarding kidney transplantation (KT), the risk of using ACEi/ARBs before surgery is not well established. Therefore, we evaluated the clinical outcomes to determine the effect of preoperative use of ACEi/ARBs on KT. METHODS: We retrospectively collected 1187 patients who received living-donor KT between January 2017 and December 2021. We conducted a propensity score-matched analysis between the ACEi/ARB(+) and ACEi/ARB(-) groups and evaluated the effects of ACEi/ARBs on delayed graft function, post-KT renal function, hyperkalemia events, rejection, and graft survival. RESULTS: The ACEi/ARB(+) group showed a similar incidence of delayed graft function as the ACEi/ARB(-) group (1.8% vs. 1.0%, P = 0.362). The risk of delayed graft function was not upregulated in the ACEi/ARB(+) group after propensity score-matching (odds ratio: 0.50, 95% confidence interval (CI) 0.13-2.00). Postoperative creatinine levels and the slope of creatinine levels after KT also were not significantly different between the two groups (creatinine slope from POD#0 to POD#7: - 0.73 ± 0.35 vs. - 0.75 ± 0.32 mg/dL/day, P = 0.464). Hyperkalemia did not occur more often in the ACEi/ARB(+) group than in the ACEi/ARB(-) group during perioperative days. Rejection-free survival (P = 0.920) and graft survival (P = 0.621) were not significantly different between the two groups. CONCLUSIONS: In KT, the preoperative use of ACEi/ARBs did not significantly affect clinical outcomes including delayed graft function, postoperative renal function, hyperkalemia events, incidence of rejection, and graft survival rates compared to the patients who did not receive ACEi/ARBs.

Immunoprotective Effect of Liver Allograft on Patients with Combined Liver and Kidney Transplantation.

BACKGROUND Simultaneous liver-kidney transplantation (SLKT) and kidney transplantation (KT) after liver transplantation (LT) provide potential treatment options for patients with end-stage liver and kidney disease. There is increasing attention being given to liver-kidney transplantation (LTKT), particularly regarding the immune-protective effects of the liver graft. This retrospective, single-center, observational study aimed to evaluate the clinical outcomes of KT in LTKT patients - either SLKT or KT after LT (KALT) - compared to KT alone (KTA). MATERIAL AND METHODS We included patients who underwent KT between January 2005 and December 2020, comprising a total of 4312 patients divided into KTA (n=4268) and LTKT (n=44) groups. The LTKT group included 11 SLKT and 33 KALT patients. To balance the difference in sample sizes between the 2 groups, we performed 3: 1 propensity score matching (PSM). RESULTS There was no significant difference in graft survival between the groups. However, the LTKT group exhibited significantly superior rejection-free survival compared to the KTA group (P.

Association of metformin with cardiovascular and graft outcomes in kidney transplant recipients with posttransplantation diabetes mellitus.

Background: Posttransplantation diabetes mellitus (PTDM) is a crucial problem after kidney transplantation. We aimed to determine whether metformin affects cardiovascular and graft outcomes in patients with PTDM. Methods: This retrospective cohort study included 1,663 kidney transplant recipients without preexisting diabetes mellitus. The patients were divided into metformin and non-metformin groups, with matched propensity scores. We also estimated metformin's effect on percutaneous coronary intervention (PCI), major adverse cardiovascular events (MACEs), acute rejection, and graft failure. Results: Of 634 recipients with PTDM, 406 recipients were treated with metformin. The incidence of PCI was 2.4% and 7.1% in the metformin and non-metformin groups, respectively (p = 0.04). The metformin group exhibited a lower risk of PCI in Cox regression analyses (hazard ratio [HR], 0.27; 95% confidence interval [CI], 0.10-0.77; p = 0.014), especially in subgroups with male sex, age over 49 years (median), long-term metformin use (mean of ≥1,729 days), and simultaneous tacrolimus administration. Long-term metformin use was also associated with lower incidence of MACEs (HR, 0.09; 95% CI, 0.01-0.67; p = 0.02). Incidence of graft failure was 9.9% and 17.0% in the metformin and non-metformin groups, respectively (p = 0.046). Both long-term use and higher dose of metformin, as well as tacrolimus administration with metformin, were associated with a lower risk of graft failure (HR, 0.29; 95% CI, 0.11-0.75; p = 0.01; HR, 0.39; 95% CI, 0.18-0.85; p = 0.02; and HR, 0.39; 95% CI, 0.19-0.79; p = 0.009, respectively). Conclusion: Metformin use is associated with a decreased risk of developing coronary artery disease and better graft outcomes in PTDM.

Significance of C4d expression in peritubular capillaries concurrent with microvascular inflammation in for-cause biopsies of ABO-incompatible renal allografts.

BACKGROUND: Pathologic diagnosis of antibody-mediated rejection (ABMR) in ABO-incompatible (ABOi) transplantation patients is often challenging because patients without ABMR are frequently immunopositive for C4d. The aim of this study was to determine whether C4d positivity with microvascular inflammation (MVI), in the absence of any detectable donor-specific antibodies (DSAs) in ABOi patients, could be considered as ABMR. METHODS: A retrospective study of 214 for-cause biopsies from 126 ABOi kidney transplantation patients was performed. Patients with MVI score of ≥2 and glomerulitis score of ≥1 (n = 62) were divided into three groups: the absolute ABMR group (DSA-positive, C4d-positive or C4d-negative; n = 36), the C4d-positive group (DSA-negative, C4d-positive; n = 22), and the C4d-negative group (DSA-negative, C4d-negative; n = 4). The Banff scores, estimated glomerular filtration rates (eGFRs), and graft failure rates were compared among groups. RESULTS: C4d-positive biopsies showed higher glomerulitis, peritubular capillaritis, and MVI scores compared with C4d-negative specimens. The C4d-positive group did not show significant differences in eGFRs and graft survival compared with the absolute ABMR group. CONCLUSION: The results indicate that C4d positivity, MVI score of ≥2, and glomerulitis score of ≥1 in ABOi allograft biopsies may be categorized and treated as ABMR cases.

Genetic diagnosis of kidney disease by whole exome sequencing and its clinical application.

The genetic spectrum of genetic kidney diseases (GKD) and the application of genetic diagnoses to patient care were assessed by whole exome sequencing (WES) of the DNA of 172 pediatric or adult patients with various kidney diseases. WES diagnosed genetic diseases in 63 (36.6%) patients. The diagnostic yields in patients with glomerulopathy were 33.8% (25/74 pts) due to variants in 10 genes, 58.8% (20/34) in patients with tubulointerstitial disease due to variants in 18 genes, 33.3% (15/45) in patients with cystic disease/ciliopathy due to variants in 10 genes, 18.2% (2/11) in patients with congenital anomalies of the kidneys and urinary tract (CAKUT) due to variants in two genes, and 12.5% (1/8) in patients with end stage kidney disease (ESKD). The diagnosis rate was high in patients aged <1-6 years (46-50.0%), and low in patients aged ≥40 years (9.1%). Renal phenotype was reclassified in 10 (15.9%) of 63 patients and clinical management altered in 10 (15.9%) of 63 patients after genetic diagnosis. In conclusion, these findings demonstrated the diagnostic utility of WES and its effective clinical application in patients, with various kinds of kidney diseases, across the different age groups.

Post-operative recurrence of focal segmental glomerulosclerosis according to pre-transplant treatment after kidney transplantation.

BACKGROUND: Recurrent focal segmental glomerulosclerosis (FSGS) after kidney transplantation (KT) is a serious complication and a significant risk factor for graft failure. However, there is no clear evidence of the effectiveness of pre-transplant treatment using plasmapheresis (PP) or rituximab in preventing post-operative FSGS recurrence after KT. METHODS: This single-center retrospective study included 99 adult patients with biopsy-proven primary FSGS who underwent KT between 2007 and 2018. The patients were divided into the pre-treatment group (N = 53, 53.5%) and no pre-treatment group (N = 46, 46.5%). In the pre-transplant group, prophylactic PP was administered before KT in patients undergoing living donor transplantation and the day after KT in those undergoing deceased donor transplantation. RESULTS: The rate of immediate post-operative recurrence was significantly higher in the no pre-treatment group (16 [34.8%]) than in the pre-treatment group (5 [9.4%]; P = 0.002). There were three cases of graft failure due to recurrent FSGS, all of which were in the no pre-treatment group. After adjusting for possible confounding factors, age (per 10-year increase; OR = 0.61, CI, 0.42-0.90; P = 0.012) and pre-transplant treatment (vs. no pre-transplant treatment; OR = 0.17, CI, 0.05-0.54; P = 0.003) were identified as significant factors associated with FSGS recurrence. The rate of death-censored graft survival was significantly superior in the pretransplant treatment group (P = 0.042). CONCLUSION: Pre-transplant treatment with PP was associated with beneficial effects on preventing FSGS recurrence after KT.

Prognostic Value of Pre- and Post-Serum Alkaline Phosphatase Among Renal Transplant Recipients.

BACKGROUND: Recent studies have shown that high levels of serum alkaline phosphatase (ALP) are associated with all-cause and cardiovascular death among patients undergoing hemodialysis. However, there is limited knowledge on the effect of ALP level in kidney transplant recipients (KTRs). The aim of this study was to evaluate if serum ALP levels before and after transplant and the changes in ALP levels are associated with graft failure and mortality. METHODS: Between January 1997 and December 2012, 3029 KTRs were enrolled in a multicenter cohort. We examined the association of pre- and posttransplant serum ALP levels and long-term outcomes in KTRs. RESULTS: Pretransplant serum ALP level >80 IU/L was associated with a hazard ratio (HR) for graft failure of 1.571 in a fully adjusted model. The graft failure rate gradually increased with ALP level increments of 20 IU/L in KTRs with ALP levels >60 IU/L. An increase in serum ALP level by 40 IU/L during the first 3 months after kidney transplant was associated with higher rates of graft failure (HR, 2.353) and higher rates of mortality (HR, 2.733). CONCLUSIONS: Elevated pre-and posttransplant serum ALP levels and increases in the serum ALP levels after kidney transplant increase the risk of graft failure and mortality among KTRs.

Parathyroidectomy versus cinacalcet in the treatment of tertiary hyperparathyroidism after kidney transplantation: a retrospective study.

BACKGROUND: Hyperparathyroidism is common in patients with chronic kidney disease with reduced renal function and has been observed after kidney transplantation. The optimal treatment for cases in which hyperparathyroidism persists after kidney transplantation has not been determined. METHODS: This retrospective study included 83 patients with tertiary hyperparathyroidism who underwent kidney transplantation between 2000 and 2018 at a single tertiary center in Korea. Sixty-four patients underwent parathyroidectomy and 19 patients were treated with cinacalcet following renal transplantation. Biochemical parameters and clinical outcomes were compared between the two groups. RESULTS: Serum calcium and parathyroid hormone (PTH) levels improved in both the parathyroidectomy and cinacalcet groups. One year after treatment, parathyroidectomy resulted in a lower mean serum calcium level than cinacalcet (9.7 ± 0.7 mg/dL vs. 10.5 ± 0.7 mg/dL, p = 0.001). Regarding serum PTH, the parathyroidectomy group showed a significantly lower PTH level than the cinacalcet group at 6 months (129.1 ± 80.3 pg/mL vs. 219.2 ± 92.5 pg/mL, p = 0.002) and 1 year (118.8 ± 75.5 pg/mL vs. 250.6 ± 94.5 pg/ mL, p < 0.001). There was no statistically significant difference in the incidence of kidney transplant rejection, graft failure, cardiovascular events, fracture risk, or bone mineral density changes between the two groups. CONCLUSION: Parathyroidectomy appears to reduce PTH and calcium levels effectively in tertiary hyperparathyroidism. However, creatinine level and allograft rejection should be monitored closely.

Hepatocellular carcinoma and cancer-related mortality after kidney transplantation with rituximab treatment.

PURPOSE: There are increased therapeutic usages of rituximab in kidney transplantation (KT). However, few studies have evaluated the effect of rituximab on cancer development following KT. This study aimed to evaluate the effect of rituximab on the cancer occurrence and mortality rate according to each type of cancer. METHODS: Five thousand consecutive recipients who underwent KT at our center were divided into era1 (1990-2007) and era2-rit- (2008-2018), and era2-rit+ (2008-2018) groups. The era2-rit+ group included patients who received single-dose rituximab (200-500 mg) as a desensitization treatment 1-2 weeks before KT. RESULTS: The 5-year incidence rates of malignant tumors after KT were 3.1%, 4.3%, and 3.5% in the era1, era2-rit-, and era2-rit+ group, respectively. The overall incidence rate of cancer after transplantation among the 3 study groups showed no significant difference (P = 0.340). The overall cancer-related mortality rate was 17.1% (53 of 310). Hepatocellular carcinoma (HCC) had the highest mortality rate (61.5%) and relative risk of cancer-related death (hazard ratio, 8.29; 95% confidence interval, 2.40-28.69; P = 0.001). However, we found no significant association between rituximab and the incidence of any malignancy. CONCLUSION: Our results suggest that single-dose rituximab for desensitization may not increase the risk of malignant disease or cancer-related mortality in KT recipients. HCC was associated with the highest risk of cancer-related mortality in an endemic area of HBV infection.

Hyperacute rejection in ABO-incompatible kidney transplantation: Significance of isoagglutinin subclass.

INTRODUCTION: ABO-incompatible transplantation has expanded the limited donor pool for kidney transplantation. Despite the successful desensitization protocols and immunosuppression, undesirable cases of hyperacute rejection occurs. OBJECTIVE: Flow cytometry was used to measure isoagglutinin titer and its IgG subclasses in assessment of the cause of hyperacute rejection in ABO-incompatible kidney transplantation. MATERIALS AND METHODS: The recipient was admitted for kidney transplantation due to end-stage renal disease. Pre-transplantation work-up for ABO-incompatible kidney transplantation included blood group typing, HLA DNA typing and HLA antibody analyses. HLA crossmatch analysis was conducted using donor lymphocytes and anti-HLA antibody assay using Luminex panel reactive antibody test (One Lambda, Inc., Canoga Park, CA). Desensitization protocol was composed of therapeutic plasma exchange sessions and rituximab. RESULTS: Despite negative HLA crossmatch results, a case of hyperacute rejection occurred after living donor kidney transplantation. Rejection resulted in immediate removal of graft, and the patient later received a second kidney transplantation. Retrospective evaluation of isoagglutinin titer and its subclasses using flow cytometry identified the cause of rejection to increased IgG1 subclass. Desensitization protocol for ABO-incompatible kidney transplantation now implements further caution for blood group O recipients. DISCUSSION: Hyperacute rejection resulting from increased IgG1 isoagglutinin subclass has not been previously confirmed using flow cytometry. Unfortunate outcome of this rejection case provides insight to how we should approach and ensure successful ABO-incompatible kidney transplantation.

Pure T-cell mediated rejection following kidney transplant according to response to treatment.

The focus of studies on kidney transplantation (KT) has largely shifted from T-cell mediated rejection (TCMR) to antibody-mediated rejection (ABMR). However, there are still cases of pure acute TCMR in histological reports, even after a long time following transplant. We thus evaluated the impact of pure TCMR on graft survival (GS) according to treatment response. We also performed molecular diagnosis using a molecular microscope diagnostic system on a separate group of 23 patients. A total of 63 patients were divided into non-responders (N = 22) and responders (N = 44). Non-response to rejection treatment was significantly associated with the following factors: glomerular filtration rate (GFR) at biopsy, ΔGFR, TCMR within one year, t score, and IF/TA score. We also found that non-responder vs. responder (OR = 3.31; P = 0.036) and lower GFR at biopsy (OR = 0.56; P = 0.026) were independent risk factors of graft failure. The responders had a significantly superior overall GS rate compared with the non-responders (P = 0.004). Molecular assessment showed a good correlation with histologic diagnosis in ABMR, but not in TCMR. Solitary TCMR was a significant risk factor of graft failure in patients who did not respond to rejection treatment.

Increasing prescription of renin-angiotensin-aldosterone system blockers associated with improved kidney prognosis in Korean IgA nephropathy patients.

BACKGROUND: We aimed to describe the characteristics of immunoglobulin A nephropathy (IgAN) in Korea with assessment for time trends. METHODS: We performed a multicenter retrospective observational cohort study including biopsy-confirmed native IgAN cases from four tertiary hospitals in Korea. Time eras of diagnosis were stratified into 1979-2003, 2004-9 and 2010-17. The prognostic variable was progression to end-stage kidney disease (ESKD) analyzed by multivariable Cox regression analysis. RESULTS: We included 1366 (from 1979 to 2003), 1636 (from 2004 to 2009) and 1442 (from 2010 to 2017) IgAN patients in this study. In the recent periods, IgAN had relatively better clinical characteristics, as patients had higher estimated glomerular filtration rates and lower baseline blood pressures than before. The use of renin-angiotensin-aldosterone system (RAAS) blockers increased from 57.7% in 1979-2003 to 80.0% in 2010-17. During a median follow-up duration of 11.3 years, 722 patients progressed to ESKD with an incidence rate of 12.5 per 1000 person-years. The 10-year risk of progression to ESKD was lower in 2010-17 compared with that of 1979-2003 [adjusted hazard ratio 0.692 (95% confidence interval 0.523-0.915)], even after adjustment for multiple clinicopathologic characteristics. The use of RAAS blockers was a significant mediator (P < 0.001) for the association between time trends and lower 10-year ESKD risk. CONCLUSIONS: Clinicopathologic characteristics of IgAN in Korea have changed over time. Although the limitation of a retrospective observational study remains, the result showed that the prognosis of IgAN has improved over the study period, possibly related to increased prescription of RAAS blockers.

Characteristics of Lymphedema in Patients Treated with Mammalian Target of Rapamycin Inhibitors.

Purpose: To investigate the characteristics of lymphedema in patients treated with mammalian target of rapamycin (mTOR) inhibitors and delineate complex decongestive therapy (CDT) outcomes. Methods and Results: We retrospectively analyzed 24 patients with mTOR inhibitor-induced lymphedema and 7 lymphedema patients (control) not treated with mTOR inhibitors, who visited the lymphedema clinic of the department of rehabilitation medicine from March 2016 to December 2019. We comprehensively reviewed clinical features, medication history, associated diseases, lymphoscintigraphy, lower extremity computed tomography venography (LE CTV), and the effect of CDT. By using ImageJ program, we measured the cross-sectional area (CSA) of muscle and subcutaneous fat of mid-thigh image in LE CTV and compared them to a control group not treated with mTOR inhibitors. Seventeen patients on sirolimus and seven patients on everolimus were included, with an approximately equal distribution of stages 2 and 3 lymphedema, and most with pitting edema. Ten patients had breast or gynecological cancer and underwent lymph node dissection. Lymphedema developed after mTOR inhibitor initiation, not postoperatively. Lymphoscintigraphy revealed decreased lymph node uptake and dermal backflow. LE CTV revealed subcutaneous honeycomb-shaped trabecular areas in the affected limbs of seven patients. Patients treated with mTOR inhibitors had a larger mean subcutaneous fat CSA and a smaller mean muscular CSA than controls. Lymphedema improved or remained unchanged after initial CDT. Daily CDT adequately controlled 11 cases, but exacerbation occurred in 5 of 7 poorly compliant patients, and cellulitis occurred in 6 patients. Conclusion: Physicians should identify mTOR inhibitor-related lymphedema early and discuss medication alternatives and CDT with patients.

Acute Rejection and Infectious Complications in ABO- and HLA-Incompatible Kidney Transplantations.

BACKGROUND Patients receiving ABO-incompatible (ABOi) or human leukocyte antigen (HLA)-incompatible (HLAi) kidney transplantation (KT) require potent immunosuppression and are thus at a higher risk of infectious complications. We evaluated the clinical outcomes of KT stratified by ABO and HLA incompatibilities and identified the factors associated with the clinical outcomes. MATERIAL AND METHODS Recipients who underwent living-related KT between 2012 and 2017 were included and classified into 4 groups: ABO-compatible and HLA-compatible (ABOc/HLAc), HLA-incompatible (ABOc/HLAi), ABO-incompatible (ABOi/HLAc), and ABO-incompatible and HLA-incompatible (ABOi/HLAi). Cox proportional hazards regression analyses were carried out to evaluate the risk factors of acute rejection. Out of the 1732 patients who underwent KT, 1190, 131, 358, and 53 were in the ABOc/HLAc, ABOi/HLAc, ABOc/HLAi, and ABOi/HLAi groups, respectively. RESULTS The ABO/HLAi group showed the lowest 5-year graft survival rate (91.7%). Death-censored graft survival was not significantly different among the groups. The mortality rate from infections was significantly higher in the ABOi/HLAi group (7.5%) than the other groups. Antibody-mediated rejection-free graft survival was the lowest in the ABOi/HLAi group, with significant differences compared with the ABOi/HLAc group (P=0.02) and the ABOc/HLAi group (P=0.03). ABOi/HLAi (hazard ratio [HR], 2.63; 95% confidence interval [CI], 1.04-6.65; P<0.01) and combined infection (HR, 1.91; 95% CI, 1.45-2.51; P<0.01) were significant risk factors for acute rejection. CONCLUSIONS Patients with both ABO and HLA incompatibilities showed inferior rates of overall patient and graft survival due to infectious complications. Infection was a prominent risk factor of acute rejection following KT after adjusting for possible confounders including ABO and HLA incompatibility.

Long-Term Outcome of Live Kidney Donation in South Korea.

BACKGROUND Kidney donors may be at increased risk for end-stage renal disease (ESRD) as well as cardiovascular and all-cause mortality. In particular, data on long-term safety after kidney donation in Asian populations are lacking. We aimed to assess the safety of live kidney donation in Korean donors by using a matched control group. MATERIAL AND METHODS We conducted a retrospective cohort study using a hospital-based database (Asan Medical Center, Seoul, Korea) and a control group from the national health insurance claims database in South Korea. We analyzed the health status of 1608 kidney donors who underwent donation between September 1990 and December 2015, and we compared their characteristics with those of matched 6426 non-donors (1: 4 ratio). We also measured the glomerular filtration rate (GFR) with 5¹Cr EDTA and urinary albumin excretion and assessed the prevalence of hypertension, diabetes, and general health status in 200 volunteer donors. RESULTS Mortality was significantly lower in kidney donors compared with the matched controls (130.2 vs. 185.4 per 100,000 person-years, P=0.02). There was no significant difference in mortality if a donor had hypertension or was a current smoker at the time of donation. There was also no significant difference in ESRD (43.1 vs. 35.2 per 100,000 person-years, P=0.07) between the 2 groups regardless of hypertension and smoking status. Among the 200 donors with measured GFR, 11.5% had GFR values <60 ml/min/1.73 m² at 9.4±5.3 years after donation. Older age (P=0.001) and female sex (P=0.021) were significantly associated with GFR values <60 mL/min/1.73 m². CONCLUSIONS Mortality and ESRD were uncommon in carefully selected kidney donors. However, donors with pre-existing risk factors should be followed up more closely to ensure long-term safety.

The usefulness of quantitative interferon-gamma releasing assay response for predicting active tuberculosis in kidney transplant recipients: A quasi-experimental study.

OBJECTIVES: We evaluated the effectiveness of IGRA-based isoniazid (INH) treatment with the diagnostic value of quantitative IGRA titer for post-transplant tuberculosis (TB) in kidney transplant (KT) recipients. METHODS: All adult KT recipients were enrolled from January 2014 to December 2017. The development of TB after KT was observed, stratified by quantitative IGRA results as well as by IGRA results with/without INH treatment. RESULTS: Of 1150 KT recipients, 322 (28%) revealed positive IGRA results (≥0.35 IU/mL) and 12 (1.0%) developed TB. Seven (3.2%) of 217 patients with positive IGRA without INH developed TB, whereas none of 105 patients with positive IGRA with INH developed TB (rate difference -1616 per 100,000 person-years, P = 0.016) and 5 (0.6%) of 828 patients with negative or indeterminate IGRA developed TB (rate difference -1388 per 100,000 person-years, P<0.001). Among the 217 positive IGRA patients without INH, 6 (6.4%) of 94 patients who had positive IGRA titer>2.96 IU/mL developed TB, whereas one (0.8%) of 123 patients who had positive IGRA titer≤2.96 IU/mL developed TB (rate difference 2964 per 100,000 person-years, P = 0.017). CONCLUSIONS: IGRA-based INH treatment with risk stratification by quantitative IGRA results appears to be effective to prevent the development of TB in KT recipients.

Pneumocystis pneumonia occurrence and prophylaxis duration in kidney transplant recipients according to perioperative treatment with rituximab.

BACKGROUND: Pneumocystis pneumonia (PCP) is a life-threatening fungal infection that can occur in kidney transplantation (KT) recipients. A growing number of KT recipients are receiving perioperative treatment with rituximab, which is associated with prolonged B-cell depletion and possible risk of PCP occurrence; however, the optimal prophylaxis duration according to rituximab treatment is yet unknown. We compared the occurrence of PCP and the duration of prophylaxis in KT recipients according to rituximab treatment. METHODS: We retrospectively analyzed 2110 patients who underwent KT between January 2009 and December 2016, who were divided into non-Rituximab group (n = 1588, 75.3%) and rituximab group (n = 522, 24.7%). RESULTS: In the rituximab group, the estimated number needed to treat (NNT) for prophylaxis prolongation from 6 to 12 months was 29.0 with a relative risk reduction of 90.0%. In the non-rituximab group, the estimated NNT value was 133.3 and the relative risk reduction was 66.4%. Rituximab treatment (hazard ratio (HR) = 3.09; P <  0.01) and acute rejection (HR = 2.19; P = 0.03) were significant risk factors for PCP in multivariate analysis. CONCLUSIONS: Our results suggest that maintaining PCP prophylaxis for 12 months may be beneficial in KT recipients treated with rituximab for desensitization or acute rejection treatment.

ABO-incompatible kidney transplantation can be successfully conducted by monitoring IgM isoagglutinin titers during desensitization.

BACKGROUND: Recent advances in desensitization techniques and immunosuppressive therapy have led to improved outcomes after ABO-incompatible (ABO-i) kidney transplantation (KT). However, questions remain unanswered, particularly regarding which type of ABO isoagglutinin-immunoglobulin M (IgM) or immunoglobulin M (IgG)-is significantly involved in antibody-mediated rejection (AMR). STUDY DESIGN AND METHODS: We retrospectively analyzed data from 120 patients who underwent ABO-i KT between 2012 and 2014. Preoperative plasma exchange was performed until the IgM isoagglutinin titer was 4 or less, regardless of the IgG titer. Clinical data were compared between patient groups with pre-KT IgG isoagglutinin titer 16 or greater (high IgG; titer range, 16-256; n = 39) and 8 or less (low IgG; titer range, -8; n = 81). RESULTS: The median follow-up periods were 59 (high IgG) and 55 (low IgG) months. Patient survival at 5 years (p = 0.314) was 100% (high IgG) and 97.4% (low IgG). Graft survival at 5 years (p = 0.480) was 100% (high IgG) and 98.7% (low IgG). AMR by anti-ABO antibody occurred in only one patient in the low-IgG group. CONCLUSION: Patients with high pre-KT IgG isoagglutinin titers had equally successful outcomes as those with low IgG titers. ABO-i KT can be successfully performed by reducing the pre-KT IgM isoagglutinin titer to 4 or less, as determined by the immediate spin tube method.

Efficacy and Safety of CKD-11101 (Proposed Biosimilar of Darbepoetin-Alfa) Compared with Darbepoetin-Alfa in Patients on Hemodialysis: A Randomized, Double-Blinded, Parallel-Group Phase III Study.

BACKGROUND: Darbepoetin-alfa is an erythropoiesis-stimulating agent (ESA) with a long elimination half-life that achieves better hemoglobin (Hb) stability than short-acting ESAs. OBJECTIVE: We aimed to evaluate the efficacy and safety of intravenous CKD-11101 (a biosimilar of darbepoetin-alfa) compared with those of darbepoetin-alfa in hemodialysis patients. METHODS: The study was performed in 24 centers in Korea between June 2015 and June 2017. The study subjects were randomized in a double-blind manner. The follow-up duration was 24 weeks, which consisted of 20 weeks of maintenance and 4 weeks of evaluation period. All patients underwent a stabilization period to achieve a target baseline Hb of 10-12 g/dL before randomization. Following randomization, patients received darbepoetin-alfa or CKD-11101 weekly or biweekly. RESULTS: A total of 403 patients were randomized into two groups, and a total of 325 patients (80.6%) completed the investigation. The differences between the two groups in terms of change in the average Hb level from baseline to evaluation were not significant. The average administered dose of ESA was similar between the groups. There was no difference in the proportion of patients who maintained the target Hb during the evaluation period [60.4% vs. 66.2% in the CKD-11101 and darbepoetin-alfa groups, respectively (p = 0.3038)]. In addition, the safety analysis, consisting of adverse events and adverse drug reactions, showed comparable results between the two groups. CONCLUSION: The changes in the level of Hb, dose of erythropoietin, and achievement rate of the target Hb during the study period were comparable between the groups. CKD-11101 has an equivalent efficacy and safety compared with darbepoetin-alfa in patients undergoing hemodialysis.

Clinical features and outcomes in kidney transplant recipients with renal cell carcinoma: a single-center study.

BACKGROUND: Previous studies have recommended a 2- to 5-year waiting time prior to kidney transplantation (KT) in patients with end-stage renal disease (ESRD) and symptomatic renal cell carcinoma (RCC) and no delay for incidental early-stage RCC. Data on Asian KT recipients are unavailable. METHODS: This is a Korean single-center retrospective study on 35 KT recipients with ESRD and RCC. Patients were classified into two groups: early KT (KT performed within 1 year after nephrectomy for RCC, including KT with simultaneous nephrectomy) and delayed KT (KT performed over than 1 year after nephrectomy for RCC). Patient survival, graft survival, and cancer recurrence were compared between both groups. RESULTS: There were no statistically significant differences in patient survival (P = 0.388), graft survival (P = 0.317), or graft rejection rate (P = 0.207) between the early and delayed KT groups. Additionally, there were no differences in pathological characteristics or RCC stage other than cancer histology: acquired cystic disease-associated RCC (47.4%) was the most common RCC type in the early KT group, whereas clear cell type (62.5%) was the most common RCC type in the delayed KT group. No RCC recurrence was observed. CONCLUSION: Patients with early-stage and asymptomatic RCC do not require a mandatory observational period prior to KT after curative nephrectomy.