The Effects of Acid on Calcium and Phosphate Metabolism.

A variety of changes in mineral metabolism aiming to restore acid-base balance occur in acid loading and metabolic acidosis. Phosphate plays a key role in defense against metabolic acidosis, both as an intracellular and extracellular buffer, as well as in the renal excretion of excess acid in the form of urinary titratable acid. The skeleton acts as an extracellular buffer in states of metabolic acidosis, as the bone matrix demineralizes, leading to bone apatite dissolution and the release of phosphate, calcium, carbonate, and citrate into the circulation. The renal handling of calcium, phosphate and citrate is also affected, with resultant hypercalciuria, hyperphosphaturia and hypocitraturia.

Therapeutic Hypothermia in Low-Risk Nonpumped Brain-Dead Kidney Donors: A Randomized Clinical Trial.

Importance: Delayed graft function in kidney-transplant recipients is associated with increased financial cost and patient burden. In donors with high Kidney Donor Profile Index whose kidneys are not pumped, therapeutic hypothermia has been shown to confer a protective benefit against delayed graft function. Objective: To determine whether hypothermia is superior to normothermia in preventing delayed graft function in low-risk nonpumped kidney donors after brain death. Design, Setting, and Participants: In a multicenter randomized clinical trial, brain-dead kidney donors deemed to be low risk and not requiring machine perfusion per Organ Procurement Organization protocol were prospectively randomized to hypothermia (34.0-35 °C) or normothermia (36.5-37.5 °C) between August 10, 2017, and May 21, 2020, across 4 Organ Procurement Organizations in the US (Arizona, Upper Midwest, Pacific Northwest, and Texas). The final analysis report is dated June 15, 2022, based on the data set received from the United Network for Organ Sharing on June 2, 2021. A total of 509 donors (normothermia: n = 245 and hypothermia: n = 236; 1017 kidneys) met inclusion criteria over the study period. Intervention: Donor hypothermia (34.0-35.0 °C) or normothermia (36.5-37.5 °C). Main Outcomes and Measures: The primary outcome was delayed graft function in the kidney recipients, defined as the need for dialysis within the first week following kidney transplant. The primary analysis follows the intent-to-treat principle. Results: A total of 934 kidneys were transplanted from 481 donors, of which 474 were randomized to the normothermia group and 460 to the hypothermia group. Donor characteristics were similar between the groups, with overall mean (SD) donor age 34.2 (11.1) years, and the mean donor creatinine level at enrollment of 1.03 (0.53) mg/dL. There was a predominance of Standard Criteria Donors (98% in each treatment arm) with similar low mean (SD) Kidney Donor Profile Index (normothermia: 28.99 [20.46] vs hypothermia: 28.32 [21.9]). Cold ischemia time was similar in the normothermia and hypothermia groups (15.99 [7.9] vs 15.45 [7.63] hours). Delayed graft function developed in 87 of the recipients (18%) in the normothermia group vs 79 (17%) in the hypothermia group (adjusted odds ratio, 0.92; 95% CI, 0.64-1.33; P = .66). Conclusions and Relevance: The findings of this study suggest that, in low-risk non-pumped kidneys from brain-dead kidney donors, therapeutic hypothermia compared with normothermia does not appear to prevent delayed graft function in kidney transplant recipients. Trial Registration: ClinicalTrials.gov Identifier: NCT02525510.

Relationships among Non-Neoplastic Histopathological Features, Kidney Function, Proteinuria, and Other Clinical Factors in Patients Undergoing Nephrectomy.

Introduction: The non-neoplastic kidney parenchyma from nephrectomies is often overlooked in routine examinations. We aimed to evaluate the associations between global glomerulosclerosis (GS), interstitial fibrosis (IF), or arteriosclerosis (AS) and estimated glomerular filtration rate (eGFR), dipstick proteinuria, and other clinical factors. Methods: We performed a cross-sectional analysis of 781 patients with nephrectomy. We used regression models with and without interaction factors. The tested exposures were GS, IF, or AS, and the outcome measures were GFR and dipstick proteinuria. Results: In multivariable analyses, increasing degrees of GS, IF, or AS were significantly associated with lower eGFR and proteinuria (p < 0.05 for each). Obesity and hypertension (HTN) modified the association between eGFR and degrees of GS, whereas proteinuria and cardiovascular disease (CVD) modified the association between eGFR and degrees of AS (p for interaction <0.05). Compared with GS <10%, GS >50% was associated with lower eGFR in patients with (-45 mL/min/1.73 m2) than without (-19 mL/min/1.73 m2) obesity, and GS >50% was associated with lower eGFR in patients with (-31 mL/min/1.73 m2) than without (-16 mL/min/1.73 m2) HTN. Compared with AS <26%, AS >50% was associated with lower eGFR in patients with (-11 mL/min/1.73 m2) than without (-6 mL/min/1.73 m2) proteinuria, and AS >50% was associated with lower eGFR in patients with (-23 mL/min/1.73 m2) than without (-7 mL/min/1.73 m2) CVD. Conclusion: Greater degrees of each GS, IF, and AS are independently associated with proteinuria and lower eGFR. Obesity, HTN, proteinuria, and CVD modify the relationship between eGFR and specific histopathological features of nephrosclerosis.

Short-term kidney transplant outcomes from severe acute respiratory syndrome coronavirus 2 lower respiratory tract positive donors.

OBJECTIVE: In this study, we aim to assess short-term allograft outcomes following deceased donor kidney transplantation from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lower respiratory tract (LRT) nucleic acid testing (NAT) positive donors. METHODS: From September to December 2021, SARS-CoV-2 NAT positive organ donors, whose solid abdominal organs were transplanted at our academic medical center were identified. Donors were stratified into having tested positive for SARS-CoV-2 in an upper respiratory tract (URT) or LRT sample. For this study, the SARS-CoV-2 LRT NAT positive deceased kidney donors and their respective recipients were examined. Donor and recipient demographic data, coronavirus disease 2019 (COVID-19)-related history, patient outcomes, as well as postoperative graft function were evaluated. RESULTS: Thirteen SARS-CoV-2 positive deceased donors were identified. Of these, eight were LRT NAT positive and yielded nine kidneys. These allografts were successfully transplanted into vaccinated and unvaccinated recipients. All recipients received standard induction immunosuppression and did not receive any prophylactic therapy for SARS-CoV-2. Two recipients had delayed graft function. At 1-month post-transplant, there was no clinical evidence of donor-derived COVID-19 or graft loss, and all recipients were free from dialysis. CONCLUSION: We describe the first case series of SARS-CoV-2 LRT NAT positive deceased kidney donors for vaccinated and unvaccinated recipients with excellent short-term allograft outcomes and no clinical evidence of donor-derived COVID-19 post-transplantation. Given the increasing prevalence of SARS-CoV-2 in the population, utilization of SARS-CoV-2 LRT NAT positive deceased donors could be considered an acceptable source of organs for renal transplantation, especially as multi-center experiences and longer-term follow-up emerge.

Severe type-B lactic acidosis in a patient with bilateral renal Burkitt's lymphoma.

INTRODUCTION: Lactic acidosis (LA) can be categorized as type A, which occurs in the presence of tissue hypoxia, or type B, occurring in the absence of tissue hypoxia. Hematologic malignancies are an uncommon cause of type B LA. CASE PRESENTATION: A 63-year-old man, HIV-negative, with a history of diabetes mellitus, hypothyroidism, and non-alcoholic fatty liver disease (NAFLD), presented to the ED complaining of acute-on-chronic lumbar pain, and was found to have high serum anion gap (AG) LA. The rest of chemistry and infectious workup was within normal limits. Despite bicarbonate therapy and fluid resuscitation, the patient remained with persistent AG metabolic acidosis and increasing lactic acid up to 14.5 mmol/L. An abdominal computerized tomography (CT) revealed multiple bilateral enhancing lesions in the kidneys, as well as gastric wall thickening. Upper gastrointestinal endoscopy with biopsy showed a high-grade Burkitt's lymphoma. Further staging showed bone marrow involvement and extensive abdominal adenopathy. After two cycles of inpatient chemotherapy with dose-adjusted EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab), the patient developed multifocal pneumonia complicated by respiratory failure. Following a prolonged ICU stay, after discussion with the family members, a decision of withdrawal of life-sustaining therapy was reached. CONCLUSION: Persistent LA, without identifiable causes of tissue hypoxia, should prompt clinicians to suspect non-hypoxic etiologies, including occult high-grade malignancies. Hematological malignancies constitute an extremely rare cause of type-B LA, carrying a poor prognosis.

Prevalence of sensorineural hearing loss in newborns in a hospital from a developing country / Prevalencia de hipoacusia neurosensorial del recién nacido: hospital en un país en vía de desarrollo

ABSTRACT Objective This study aimed to determine the prevalence of nonsyndromic congenital sensorineural hearing loss at the Hospital Universitario San Ignacio, Bogotá, Colombia, and to describe the risk factors associated with this condition. Materials and Methods A prospective, observational cross-sectional study with bivariate analysis was conducted. A three-phase process using the Otoacoustic Emissions test screened all live newborns between June 2013 and June 2014. Negative cases were confirmed by Automated Auditory Brainstem Response test. Results A total of 962 newborns were screened with Otoacoustic Emissions test bilaterally: 401 males (46.36%), 464 females (53.64%). The mean weight was 2 798.10 g (95%CI: 2 766.51 - 2 839.76). The mean height was 48.60 cm (95%CI: 48.38 - 48.79). The mean age was 16.24 days (95%CI: 15.47 - 17.01). The mean maternal age was 27.37 years (95%CI: 26.76 - 27.98). There was a family history of hearing loss in 9.48% of the cases (n=90), and a family history of genetic diseases in 100 cases (10.56%). There were 14 cases of TORCH infections (1.45%), 375 admissions to the NICU (39.06%), 160 cases of neonatal jaundice (20.1%), and 79 cases of postpartum infections (8.21%). One live newborn presented with microtia. Conclusions The prevalence of congenital sensorineural hearing loss was 0.31% in both ears, and 0.11% in one ear. Currently, Colombia lacks a public universal newborn hearing screening program, and its future implementation faces great challenges.(AU)

RESUMEN Objetivos Este estudio busca determinar la prevalencia de la hipoacusia neurosensorial congénita no sindrómica en el Hospital Universitario San Ignacio de Bogotá, Colombia, y describir sus factores de riesgo. Materiales y Métodos Estudio observacional, transversal y prospectivo con análisis bivariado. Todos los nacidos vivos entre junio de 2013 y junio de 2014 fueron tamizados con Emisiones Otoacusticas. Los casos negativos fueron confirmados con Potenciales Evocados Auditivos de Tronco Cerebral. Resultados Un total de 962 neonatos fueron tamizados de forma bilateral con Emisiones Otoacústicas: 401 de sexo masculino (46,36%) y 464 de sexo femenino (53,64%). El peso promedio fue de 2 798,10 g (IC95%: 2 766,51 - 2 839,76). La talla promedio fue de 48.60 cm (IC95%: 48,38 - 48,79). La edad promedio fue de 16,24 días (IC95%: 15,47 -17,01). La edad materna promedio fue de 27,37 años (IC95%: 26,76 - 27,98). Se encontró historia familiar de hipoacusia en 9.48% de los casos (n=90) e historia familiar de enfermedades genéticas en 100 casos (10,56%). Hubo 14 casos de infecciones por TORCH (1,45%), 375 admisiones a la UCI Neonatal (39,06%), 160 casos de ictericia neonatal (20,1%) y 79 casos de infecciones postnatales (8,21%). Un nacido vivo presentó microtia. Conclusiones Se encontró una prevalencia de hipoacusia neurosensorial congénita del 0,31% en ambos oídos y de 0,11% en un oído. Actualmente Colombia carece de un programa nacional de tamización de hipoacusia neonatal, y su futura implementación conlleva grandes retos.(AU)

Prevalence of sensorineural hearing loss in newborns in a hospital from a developing country.

OBJECTIVE: This study aimed to determine the prevalence of nonsyndromic congenital sensorineural hearing loss at the Hospital Universitario San Ignacio, Bogotá, Colombia, and to describe the risk factors associated with this condition. MATERIALS AND METHODS: A prospective, observational cross-sectional study with bivariate analysis was conducted. A three-phase process using the Otoacoustic Emissions test screened all live newborns between June 2013 and June 2014. Negative cases were confirmed by Automated Auditory Brainstem Response test. RESULTS: A total of 962 newborns were screened with Otoacoustic Emissions test bilaterally: 401 males (46.36%), 464 females (53.64%). The mean weight was 2 798.10 g (95%CI: 2 766.51 - 2 839.76). The mean height was 48.60 cm (95%CI: 48.38 - 48.79). The mean age was 16.24 days (95%CI: 15.47 - 17.01). The mean maternal age was 27.37 years (95%CI: 26.76 - 27.98). There was a family history of hearing loss in 9.48% of the cases (n=90), and a family history of genetic diseases in 100 cases (10.56%). There were 14 cases of TORCH infections (1.45%), 375 admissions to the NICU (39.06%), 160 cases of neonatal jaundice (20.1%), and 79 cases of postpartum infections (8.21%). One live newborn presented with microtia. CONCLUSIONS: The prevalence of congenital sensorineural hearing loss was 0.31% in both ears, and 0.11% in one ear. Currently, Colombia lacks a public universal newborn hearing screening program, and its future implementation faces great challenges.