Acidic Urine pH and Clinical Outcome of Lower Urinary Tract Infection in Kidney Transplant Recipients Treated with Ciprofloxacin and Fosfomycin

Different factors, including antimicrobial resistance, may diminish the effectiveness of antibiotic therapy, challenging the management of post-transplant urinary tract infection (UTI). The association of acidic urine pH with microbiological and clinical outcomes was evaluated after fosfomycin or ciprofloxacin therapy in 184 kidney transplant recipients (KTRs) with UTI episodes by Escherichia coli (N = 115) and Klebsiella pneumoniae (N = 69). Initial urine pH, antimicrobial therapy, and clinical and microbiological outcomes, and one- and six-month follow-up were assessed. Fosfomycin was prescribed in 88 (76.5%) E. coli and 46 (66.7%) K. pneumoniae UTI episodes in the total cohort. When the urine pH ≤ 6, fosfomycin was prescribed in 60 (52.2%) E. coli and 29 (42.0%) K. pneumoniae. Initial urine pH ≤ 6 in E. coli UTI was associated with symptomatic episodes (8/60 vs. 0/55, p = 0.04) at one-month follow-up, with a similar trend in those patients receiving fosfomycin (7/47 vs. 0/41, p = 0.09). Acidic urine pH was not associated with microbiological or clinical cure in K. pneumoniae UTI. At pH 5, the ciprofloxacin MIC90 increased from 8 to >8 mg/L in E. coli and from 4 to >8 mg/L in K. pneumoniae. At pH 5, the fosfomycin MIC90 decreased from 8 to 4 mg/L in E. coli and from 512 to 128 mg/L in K. pneumoniae. Acidic urine is not associated with the microbiological efficacy of fosfomycin and ciprofloxacin in KTRs with UTI, but it is associated with symptomatic UTI episodes at one-month follow-up in E. coli episodes.This study has been funded by Instituto de Salud Carlos III, through the projects PI17/01405 and PI20/01255, by the Subdirección General de Evaluación y Fomento de la Investigación, Ministerio de Economía, Industria y Competitividad, US-1381501 US/JUNTA/FEDER, UE, by the Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía, Industria y Competitividad, and the Spanish Network for Research in Infectious Diseases (REIPI, RD16/0016/0009) and co-funded by the European Union.Peer reviewe

Factors associated with the humoral response after three doses of COVID-19 vaccination in kidney transplant recipients

[Introduction] Kidney transplant recipients showed a weak humoral response to the mRNA COVID-19 vaccine despite receiving three cumulative doses of the vaccine. New approaches are still needed to raise protective immunity conferred by the vaccine administration within this group of high-risk patients.[Methods] To analyze the humoral response and identify any predictive factors within these patients, we designed a prospective monocentric longitudinal study of Kidney transplant recipients (KTR) who received three doses of mRNA-1273 COVID-19 vaccine. Specific antibody levels were measured by chemiluminescence. Parameters related to clinical status such as kidney function, immunosuppressive therapy, inflammatory status and thymic function were analyzed as potential predictors of the humoral response.[Results] Seventy-four KTR and sixteen healthy controls were included. One month after the administration of the third dose of the COVID-19 vaccine, 64.8% of KTR showed a positive humoral response. As predictive factors of seroconversion and specific antibody titer, we found that immunosuppressive therapy, worse kidney function, higher inflammatory status and age were related to a lower response in KTR while immune cell counts, thymosin-a1 plasma concentration and thymic output were related to a higher humoral response. Furthermore, baseline thymosin-a1 concentration was independently associated with the seroconversion after three vaccine doses.[Discussion] In addition to the immunosuppression therapy, condition of kidney function and age before vaccination, specific immune factors could also be relevant in light of optimization of the COVID-19 vaccination protocol in KTR. Therefore, thymosin-a1, an immunomodulatory hormone, deserves further research as a potential adjuvant for the next vaccine boosters.This study was supported by a grant from the Fondo de Investigación Sanitaria (FIS/PI21/00357), which is co-founded by Fondos Europeos para el Desarrollo Regional (FEDER) “Una manera de hacer Europa”. VG-R, IO-M and AB-R were supported by Instituto de Salud Carlos III (CD19/00143, FI19/00298 and CM19/00051, respectively). MP-B was supported by the Consejería de Transformación Económica, Industria, Conocimiento y Universidades [DOC_01646 to MP-B] and YP was supported by the Consejería de Salud y Familias of Junta de Andalucía through the “Nicolás Monardes” [RC-0006-2021].Peer reviewe

Impact of Treating Asymptomatic Bacteriuria in Kidney Transplant Recipients: A Prospective Cohort Study

This study aims to define the epidemiologic, clinical, and microbiological features of asymptomatic bacteriuria (AB) and cystitis in kidney transplantation recipients (KTRs), and to determine the impact of antimicrobial therapy of AB and the risk factors of cystitis. We conducted a prospective observational study of AB and cystitis in KTRs from January to June 2017. One-hundred ninety seven KTRs were included: 175 (88.8%) with AB and 22 (11.2%) with cystitis. The most frequent etiologies were Escherichia coli, Klebsiellapneumoniae, Enterococcusfaecalis, and Pseudomonas aeruginosa. No differences were observed regarding the etiologies, antimicrobial susceptibility patterns, and microbiologic outcomes in AB vs. cystitis. The treatment of AB diminished the microbiological cure and increased the rates of microbiologic relapses and reinfections; in addition, treated AB patients showed a trend of developing symptomatic urinary tract infection in the following six months. The analysis of the data identified the following independent risk factors for cystitis during the six months of follow-up: AB treatment, thymoglobulin induction, previous acute pyelonephritis, and time since transplantation < 1 year. In summary, considering the lack of clinical benefits of treating AB and its impact on cystitis development in the follow-up, we support the recommendation of not screening for or treating AB.This work was supported by the Instituto de Salud Carlos III, Subdirección General de Evaluación y Fomento de la Investigación, Ministerio de Economía, Industria y Competitividad (PI17-01405) and by Plan Nacional de I + D + i 2013–2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0009)-cofinanced by European Development Regional Fund “A way to achieve Europe”, Operative program Intelligent Growth 2014–2020. G.M.-G. was supported by a Río Hortega research contract from the Instituto de Salud Carlos III.). M.E.P.I. is supported by the “Contract to Access to the Spanish System of Research and Innovation, V Research Program of the University of Seville” (USE13901-D) grant.Ye

Direct-Acting Antivirals for the Treatment of Kidney Transplant Patients with Chronic Hepatitis C Virus Infection in Spain : A Long-Term Prospective Observational Study

Direct-Acting antivirals (DAA) allow effective and safe eradication of hepatitis C virus (HCV) in most patients. There are limited data on the long-Term effects of all-oral, interferon-free DAA combination therapies in kidney transplant (KT) patients infected with HCV. Here we evaluated the long-Term tolerability, efficacy, and safety of DAA combination therapies in KT patients with chronic HCV infection. Clinical data from KT patients treated with DAA were collected before, during, and after the treatment, including viral response, immunosuppression regimens, and kidney and liver function. Patients (N = 226) were mostly male (65.9%) aged 56.1 ± 10.9 years, with a median time from KT to initiation of DAA therapy of 12.7 years and HCV genotype 1b (64.6%). Most patients were treated with sofosbuvir-based therapies. Rapid virological response at 1 month was achieved by 89.4% of the patients and sustained virological response by week 12 by 98.1%. Liver function improved significantly after DAA treatment. Tacrolimus dosage increased 37% from the beginning of treatment (2.5 ± 1.7 mg/d) to 1 year after the start of DAA treatment (3.4 ± 1.9 mg/d, P < 0.001). Median follow-up was 37.0 months (interquartile range, 28.4-41.9) and death-censored graft survival was 91.1%. Adverse events resulting from DAA treatment, especially anemia, were reported for 31.0% of the patients. Chronic HCV infection can be treated efficiently and safely with DAA therapy in KT patients. Most patients retained stable kidney function and improved liver function. Tacrolimus dose had to be increased in most patients, potentially as a result of better liver function

Impact of treating asymptomatic bacteriuria in kidney transplant recipients: a prospective cohort study

This study aims to define the epidemiologic, clinical, and microbiological features of asymptomatic bacteriuria (AB) and cystitis in kidney transplantation recipients (KTRs), and to determine the impact of antimicrobial therapy of AB and the risk factors of cystitis. We conducted a prospective observational study of AB and cystitis in KTRs from January to June 2017. One-hundred ninety seven KTRs were included: 175 (88.8%) with AB and 22 (11.2%) with cystitis. The most frequent etiologies were Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, and Pseudomonas aeruginosa. No differences were observed regarding the etiologies, antimicrobial susceptibility patterns, and microbiologic outcomes in AB vs. cystitis. The treatment of AB diminished the microbiological cure and increased the rates of microbiologic relapses and reinfections; in addition, treated AB patients showed a trend of developing symptomatic urinary tract infection in the following six months. The analysis of the data identified the following independent risk factors for cystitis during the six months of follow-up: AB treatment, thymoglobulin induction, previous acute pyelonephritis, and time since transplantation < 1 year. In summary, considering the lack of clinical benefits of treating AB and its impact on cystitis development in the follow-up, we support the recommendation of not screening for or treating AB.Instituto de Salud Carlos III, Subdirección General de Evaluación y Fomento de la Investigación, Ministerio de Economía, Industria y Competitividad PI17-01405Plan Nacional de I + D + i 2013-2016Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Red Española de Investigación en Enfermedades Infecciosas REIPI RD16 / 0016/0009Cofinanciada por el Fondo Regional de Desarrollo Europeo 2014-2020. G.M.-G.Contrato de Acceso al Sistema Español de Investigación e Innovación, V Programa de Investigación de la Universidad de Sevilla USE13901-

Acidic Urine pH and Clinical Outcome of Lower Urinary Tract Infection in Kidney Transplant Recipients Treated with Ciprofloxacin and Fosfomycin

Different factors, including antimicrobial resistance, may diminish the effectiveness of antibiotic therapy, challenging the management of post-transplant urinary tract infection (UTI). The association of acidic urine pH with microbiological and clinical outcomes was evaluated after fosfomycin or ciprofloxacin therapy in 184 kidney transplant recipients (KTRs) with UTI episodes by Escherichia coli (N = 115) and Klebsiella pneumoniae (N = 69). Initial urine pH, antimicrobial therapy, and clinical and microbiological outcomes, and one- and six-month follow-up were assessed. Fosfomycin was prescribed in 88 (76.5%) E. coli and 46 (66.7%) K. pneumoniae UTI episodes in the total cohort. When the urine pH ≤ 6, fosfomycin was prescribed in 60 (52.2%) E. coli and 29 (42.0%) K. pneumoniae. Initial urine pH ≤ 6 in E. coli UTI was associated with symptomatic episodes (8/60 vs. 0/55, p = 0.04) at one-month follow-up, with a similar trend in those patients receiving fosfomycin (7/47 vs. 0/41, p = 0.09). Acidic urine pH was not associated with microbiological or clinical cure in K. pneumoniae UTI. At pH 5, the ciprofloxacin MIC90 increased from 8 to >8 mg/L in E. coli and from 4 to >8 mg/L in K. pneumoniae. At pH 5, the fosfomycin MIC90 decreased from 8 to 4 mg/L in E. coli and from 512 to 128 mg/L in K. pneumoniae. Acidic urine is not associated with the microbiological efficacy of fosfomycin and ciprofloxacin in KTRs with UTI, but it is associated with symptomatic UTI episodes at one-month follow-up in E. coli episodes