1
|
Trigolet M, Bonsante F, Guignard JP, Gouyon JB, Iacobelli S. Urinary protein to creatinine ratio during the first month of life in very preterm infants-a prospective cohort study (PROTIPREMA). Pediatr Nephrol 2023; 38:721-727. [PMID: 35759001 DOI: 10.1007/s00467-022-05653-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/02/2022] [Accepted: 06/02/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND Preterm infants have physiological proteinuria and values of urine protein to creatinine ratio (UPr/Cr) are higher compared to full-term infants during the first week of life. Few investigations explored the changes of proteinuria in very preterm infants (VPI, ≤ 31 weeks of gestation) older than a week, and it is unclear whether high and persistent proteinuria is associated with kidney injury in this population. This study aimed to (1) observe the changes of UPr/Cr during the first month of life in VPI and (2) describe clinical and biological variables associated with the changes of UPr/Cr. METHODS Spot urine samples for UPr/Cr were collected on the first day of life (DOL1) and then on DOL2-3, DOL5-6, second week of life (WOL2), WOL3, and WOL4 in VPI cared for in a third-level NICU. We tested the relationship of UPr/Cr with perinatal variables and diseases. RESULTS A total of 1140 urine samples were obtained for 190 infants. UPr/Cr values (mg/mmol) (median with interquartile) at DOL1, DOL2, DOL3, WOL2, WOL3, and WOL4 were, respectively, 191 (114-399), 226 (152-319), 225 (156-350), 282 (200-488), 308 (188-576), and 325 (175-664). At the multivariate analysis, lower gestational age (GA) and increasing postnatal age were the only variables significantly associated with higher UPr/Cr values (p < 0.001). There was wide intra- and interindividual variability in UPr/Cr, especially in infants with higher GA and clinical stability. CONCLUSIONS In VPI, UPr/Cr is higher at lower GA and increases with advancing postnatal age. High persistent proteinuria is not associated with clinical and biological variables reflecting kidney injury during the first month of life. A higher resolution version of the Graphical abstract is available as Supplementary information.
Collapse
Affiliation(s)
- Marine Trigolet
- Néonatologie, Réanimation Néonatale Et Pédiatrique, CHU La Réunion, Site Sud, Saint Pierre, France
| | - Francesco Bonsante
- Néonatologie, Réanimation Néonatale Et Pédiatrique, CHU La Réunion, Site Sud, Saint Pierre, France.,Centre d'Études Périnatales de L'Océan Indien, Université de La Réunion, UR7388, Saint Pierre, France
| | | | - Jean-Bernard Gouyon
- Centre d'Études Périnatales de L'Océan Indien, Université de La Réunion, UR7388, Saint Pierre, France
| | - Silvia Iacobelli
- Néonatologie, Réanimation Néonatale Et Pédiatrique, CHU La Réunion, Site Sud, Saint Pierre, France. .,Centre d'Études Périnatales de L'Océan Indien, Université de La Réunion, UR7388, Saint Pierre, France.
| |
Collapse
|
2
|
Urine podocyte mRNA loss in preterm infants and related perinatal risk factors. Pediatr Nephrol 2023; 38:729-738. [PMID: 35759002 PMCID: PMC9842585 DOI: 10.1007/s00467-022-05663-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 06/05/2022] [Accepted: 06/07/2022] [Indexed: 01/21/2023]
Abstract
BACKGROUND Preterm birth has been identified as a risk factor for development of long-term chronic kidney disease. Podocyte loss has been reported to contribute to this process in preterm animal models. However, details about podocyte loss in preterm infants and related perinatal risk factors have not been well clarified. METHODS Forty full-term infants and 106 preterm infants were enrolled. Urine samples were collected from full-term infants within 4-7 days of birth and preterm infants at 37-40 weeks of corrected age. Levels of urine podocin mRNA, urine protein (UP), and urine microalbumin (UMA) were measured, and the relationship between these markers was evaluated. Clinical information in these infants was collected, and potential correlates that may lead to increased podocyte loss during the perinatal period were identified using linear regression analysis. RESULTS Urine podocyte loss indicated by the urine podocin mRNA to creatinine ratio (UpodCR) was higher in preterm infants than in full-term infants. UpodCR was correlated with the levels of UP and UMA. Multiple linear regression analysis also showed that lower gestational age (GA) at birth and small for gestational age (SGA) were high risk factors for urine podocyte loss. CONCLUSIONS Increasing urine podocyte loss was identified in preterm infants. Moreover, perinatal factors were associated with podocyte loss and may be a potential direction for comprehensive research and intervention in this field. A higher resolution version of the Graphical abstract is available as Supplementary information.
Collapse
|
3
|
Nugent JT, Reardon J, Crana C, Greenberg JH, Warejko JK, Goodwin JE. Fanconi syndrome, nephrotic-range proteinuria, and hypoalbuminemia in a newborn-Occam's razor or Hickam's dictum? Answers. Pediatr Nephrol 2022; 37:129-132. [PMID: 34633532 DOI: 10.1007/s00467-021-05255-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 11/26/2022]
Affiliation(s)
- James T Nugent
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA.
| | - Juliann Reardon
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Christine Crana
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Jason H Greenberg
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Jillian K Warejko
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Julie E Goodwin
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| |
Collapse
|
4
|
Ponthier L, Trigolet M, Chianea T, Mons F, Yardin C, Guigonis V, El Hamel C. Distribution of proteinuria- and albuminuria-to-creatinine ratios in preterm newborns. Pediatr Nephrol 2021; 36:1515-1524. [PMID: 33394192 DOI: 10.1007/s00467-020-04838-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/18/2020] [Accepted: 10/21/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Urine protein assessment is important when glomerular disease or injury is suspected. Normal values of proteinuria already published for preterm newborns suffer from limitation, with small cohorts of patients. This prospective study was conducted to update the urine total protein- and albumin-to-creatinine ratio values. METHODS Urine samples were collected from 231 preterm newborns within the first 48 h (D0-1) and/or between 72-120 h of life (D3-4). Total protein, albumin, and creatinine were measured, their distribution and upper-limit values determined. RESULTS At D0-1 and D3-4, respectively, the median for the total protein-to-creatinine ratio were 80 and 107 mg/mmol (upper-limit values 223 and 289 mg/mmol) in the whole studied population, 149 and 214 mg/mmol in children born before 29 weeks of gestational age, 108 and 130 mg/mmol in those born between 29 and 33 weeks, and 61 and 93 mg/mmol in those born after 33 weeks. For the albumin-to-creatinine ratio, the median were 12 and 17 mg/mmol (upper-limit values 65 and 62 mg/mmol) in the whole studied population, 22 and 50 mg/mmol in children born before 29 weeks, 21 mg/mmol in those born between 29 and 33 weeks, and 8 and 12 mg/mmol in those born after 33 weeks. The use of nephrotoxic drugs and mechanical ventilation seems to influence proteinuria and albuminuria values. CONCLUSIONS We report distribution of proteinuria- and albuminuria-to-creatinine in preterm newborns, including the upper-limit values. These values should be taken into account in the detection and diagnosis of glomerular disease and/or injury in daily clinical practice. Graphical abstract.
Collapse
Affiliation(s)
- Laure Ponthier
- Collection Biologique Hôpital de la Mère et de l'Enfant (CB-HME), University Hospital Center, 8 Avenue Dominique Larrey, 87042 Cedex, Limoges, France.,Department of Pediatric, University Hospital Center, Limoges, France
| | - Marine Trigolet
- Department of Pediatric, University Hospital Center, Limoges, France
| | - Thierry Chianea
- Department of Biochemistry, University Hospital Center, Limoges, France
| | - Fabienne Mons
- Department of Pediatric, University Hospital Center, Limoges, France
| | - Catherine Yardin
- Collection Biologique Hôpital de la Mère et de l'Enfant (CB-HME), University Hospital Center, 8 Avenue Dominique Larrey, 87042 Cedex, Limoges, France.,Department of Cytogenetics and clinical genetics, University Hospital Center, Limoges, France.,CNRS, XLIM, UMR7252, Limoges University, Limoges, France
| | - Vincent Guigonis
- Collection Biologique Hôpital de la Mère et de l'Enfant (CB-HME), University Hospital Center, 8 Avenue Dominique Larrey, 87042 Cedex, Limoges, France.,Department of Pediatric, University Hospital Center, Limoges, France
| | - Chahrazed El Hamel
- Collection Biologique Hôpital de la Mère et de l'Enfant (CB-HME), University Hospital Center, 8 Avenue Dominique Larrey, 87042 Cedex, Limoges, France. .,Department of Pediatric, University Hospital Center, Limoges, France.
| |
Collapse
|
5
|
Urinary Cystatin-C, a marker to assess and monitor neonatal kidney maturation and function: validation in twins. Pediatr Res 2021; 89:932-939. [PMID: 32422644 DOI: 10.1038/s41390-020-0965-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/14/2020] [Accepted: 04/29/2020] [Indexed: 11/08/2022]
Abstract
BACKGROUND Nephrogenesis is a complex process of nephron formation and maturation that can be compromised by preterm delivery and intrauterine growth restriction. This study aimed to evaluate and compare urinary Cys-C levels with renal volume in a cohort of preterm and term twins, adequate for gestational age or intrauterine growth restricted, to investigate their values in different conditions of nephrogenesis. METHODS The study was performed on twins at 30-40 days of postnatal corrected age: renal volumes were measured by 3D ultrasound technology and urine samples were analyzed for Cystatin-C. A follow-up was performed by Cystatin-C. RESULTS Renal volumes in preterm and intrauterine growth-restricted twins showed values significantly lower than those observed in term twins and were inversely correlated to urinary Cystatin-C levels. During the follow-up, intrauterine growth-restricted twins showed amplified levels of urinary Cystatin-C; in contrast, invariable or decreased levels were observed in adequate for gestational age twins. CONCLUSIONS Urinary Cystatin-C, evaluated when intrauterine/extrauterine nephrogenesis could be considered completed, concurrently with renal volume assessment can improve the identification of neonates with initial kidney impairment. Its potential value as a useful marker in monitoring physiological/pathological renal conditions could be considered, mainly for neonates at elevated risk of developing long-term renal diseases. IMPACT Urinary Cys-C levels are inversely correlated to renal volumes and reflect nephrogenesis conditions. No data in literature are reported regarding: (a) the concurrent assessment of renal volumes and urinary levels of Cystatin-C in preterm and term twins with different conditions of gestational life, i.e., AGA and IUGR and (b) the follow-up of IUGR and preterm neonates using the urinary Cys-C determination. The variations of urinary Cys-C levels, observed in the follow-up of preterm and/or IUGR neonates, support the usefulness of monitoring those neonates with altered nephrogenesis, who are later at risk for renal impairment and for long-term renal diseases.
Collapse
|
6
|
El Hamel C, Chianea T, Thon S, Lepichoux A, Yardin C, Guigonis V. Normal values of urine total protein- and albumin-to-creatinine ratios in term newborns. Pediatr Nephrol 2017; 32:113-118. [PMID: 27307246 DOI: 10.1007/s00467-016-3427-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 11/28/2022]
Abstract
BACKGROUND It is important to have an accurate assessment of urinary protein when glomerulopathy or kidney injury is suspected. Currently available normal values for the neonate population have limited value, in part because they are based on small populations and obsolete creatinine assays. We have performed a prospective study with the aim to update the normal upper values of the urinary total protein-to-creatinine and albumin-to-creatinine ratios in term newborns. METHODS Urine samples were collected from 277 healthy, full-term newborns within the first 48 hours (D0-1) and between 72 and 120 h of life (D3-4). Total protein, albumin, creatinine and osmolality were measured and the upper limit of normal (upper-limit) values determined. RESULTS At D0-1 and D3-4, the upper-limit values for the total protein-to-creatinine ratio were 1431 and 1205 mg/g (162 and 136 g/mol) and those for the albumin-to-creatinine ratio were 746 and 301 mg/g (84 and 34 g/mol), respectively. The upper-limit values were significantly higher at D0-1 than at D3-4 only for the albumin-to-creatinine ratio. CONCLUSION This study determined the upper limit of normal values for urinary total protein-to-creatinine and albumin-to-creatinine ratios in the largest population of newborns studied to date. These values can therefore be considered as the most clinically relevant data currently available for the detection and diagnosis of glomerular injury in daily clinical practice in this population.
Collapse
Affiliation(s)
- Chahrazed El Hamel
- Collection Biologique, Hôpital de la Mère et de l'Enfant (CB-HME), CHU Limoges, Limoges, France. .,Service de pédiatrie, Hôpital de la mère et de l'enfant, CHU Limoges, Limoges Cedex, France. .,Comité de l'hôpital de la mère et de l'enfant pour la recherche clinique (CHREC), CHU Limoges, Limoges, France.
| | | | - Séverine Thon
- Service de pédiatrie, Hôpital de la mère et de l'enfant, CHU Limoges, Limoges Cedex, France
| | | | - Catherine Yardin
- Collection Biologique, Hôpital de la Mère et de l'Enfant (CB-HME), CHU Limoges, Limoges, France.,Comité de l'hôpital de la mère et de l'enfant pour la recherche clinique (CHREC), CHU Limoges, Limoges, France.,Laboratoire de cytogénétique, CHU Limoges, Limoges, France
| | - Vincent Guigonis
- Collection Biologique, Hôpital de la Mère et de l'Enfant (CB-HME), CHU Limoges, Limoges, France.,Service de pédiatrie, Hôpital de la mère et de l'enfant, CHU Limoges, Limoges Cedex, France.,Comité de l'hôpital de la mère et de l'enfant pour la recherche clinique (CHREC), CHU Limoges, Limoges, France
| |
Collapse
|
7
|
Aisa MC, Cappuccini B, Barbati A, Orlacchio A, Baglioni M, Di Renzo GC. Biochemical parameters of renal impairment/injury and surrogate markers of nephron number in intrauterine growth-restricted and preterm neonates at 30-40 days of postnatal corrected age. Pediatr Nephrol 2016; 31:2277-2287. [PMID: 27557556 DOI: 10.1007/s00467-016-3484-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 07/31/2016] [Accepted: 08/02/2016] [Indexed: 12/25/2022]
Abstract
BACKGROUND Premature and/or intrauterine growth-restricted neonates have an increased risk of developing postnatal renal injuries in later life. Studies on renal physiology in these neonates at a corrected age of 30-40 days are scarce and mostly relate to preterm infants. The data from these studies often lack the results of correlation analyses between biochemical parameters and nephron number-data which could provide additional insight and/or improve recognition of individuals at higher risk of renal failure. METHODS Urinary total protein and albumin levels and N-acetyl-β-D-glucosaminidase and cathepsin B activity were evaluated in preterm and intrauterine growth-restricted infants at a corrected age of 30-40 days and compared to data from a healthy control neonate population. The data were then associated with predominant susceptibility factors of renal damage related to low nephron number, such as gestational age, birth weight, total renal volume and renal cortex volume. RESULTS Compared to the control neonate population, we found significantly increased levels of all biochemical parameters tested in the intrauterine growth-restricted neonates, whereas in the preterm infants we observed a significant increase in cathepsin B activity, total protein level and, to a lesser extent, albumin level. Cathepsin B activity showed a significant, strong and inverse correlation with all surrogate markers of nephron number and was also strongly and positively correlated with urinary albumin level. CONCLUSIONS At this postnatal age, we found that lower nephron number in low birth weight neonates was associated to tubular impairment/injury that could be concurrent with a dysfunction of glomerular permeability. Urinary cathepsin B activity may be a candidate marker for the early prediction of renal susceptibility to damage in low birth weight neonates.
Collapse
Affiliation(s)
- Maria Cristina Aisa
- Section of Obstetrics and Gynecology, Department of Surgical and Biomedical Sciences, University of Perugia, Perugia, Italy. .,Section of Biochemistry, Department of Agricultural Sciences, Food and Environment, University of Perugia, Perugia, Italy.
| | - Benito Cappuccini
- Department of Neonatology, Hospital S. M. della Misericordia, Perugia, Italy.,Centre of Perinatal Medicine, University of Perugia, Perugia, Italy.,GeBiSa, Research Foundation, Perugia, Italy
| | - Antonella Barbati
- Section of Obstetrics and Gynecology, Department of Surgical and Biomedical Sciences, University of Perugia, Perugia, Italy
| | - Aldo Orlacchio
- Centre of Perinatal Medicine, University of Perugia, Perugia, Italy.,GeBiSa, Research Foundation, Perugia, Italy
| | | | - Gian Carlo Di Renzo
- Section of Obstetrics and Gynecology, Department of Surgical and Biomedical Sciences, University of Perugia, Perugia, Italy.,Centre of Perinatal Medicine, University of Perugia, Perugia, Italy.,GeBiSa, Research Foundation, Perugia, Italy
| |
Collapse
|
8
|
Abstract
PURPOSE OF REVIEW Neonatal proteinuria and hematuria while not common can have potentially devastating consequences if left undiagnosed and untreated. It is important to distinguish between inherited and acquired causes of proteinuria to initiate appropriate and timely treatment. With regards to hematuria, it is critical to identify true hematuria from pseudo-hematuria to balance between thorough investigation and unnecessary laboratory work up. This review provides an overview of the common causes of hematuria and proteinuria in a neonate. RECENT FINDINGS The identification of genetic mutations in nephrotic syndrome has improved our understanding of the role of various proteins that play an important role in maintaining the glomerular filtration barrier. With the advancement in our ability to provide care for extreme premature neonates, the incidence of acute kidney injury has increased in these neonates along with proteinuria and hematuria. SUMMARY Persistent proteinuria after neonatal acute kidney injury would be of interest in regards to the risk of developing future chronic kidney disease and hypertension.
Collapse
|
9
|
Gubhaju L, Sutherland MR, Horne RSC, Medhurst A, Kent AL, Ramsden A, Moore L, Singh G, Hoy WE, Black MJ. Assessment of renal functional maturation and injury in preterm neonates during the first month of life. Am J Physiol Renal Physiol 2014; 307:F149-58. [PMID: 24899060 DOI: 10.1152/ajprenal.00439.2013] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Worldwide, approximately 10% of neonates are born preterm. The majority of preterm neonates are born when the kidneys are still developing; therefore, during the early postnatal period renal function is likely reflective of renal immaturity and/or injury. This study evaluated glomerular and tubular function and urinary neutrophil gelatinase-associated lipocalin (NGAL; a marker of renal injury) in preterm neonates during the first month of life. Preterm and term infants were recruited from Monash Newborn (neonatal intensive care unit at Monash Medical Centre) and Jesse McPherson Private Hospital, respectively. Infants were grouped according to gestational age at birth: ≤28 wk (n = 33), 29-31 wk (n = 44), 32-36 wk (n = 32), and term (≥37 wk (n = 22)). Measures of glomerular and tubular function were assessed on postnatal days 3-7, 14, 21, and 28. Glomerular and tubular function was significantly affected by gestational age at birth, as well as by postnatal age. By postnatal day 28, creatinine clearance remained significantly lower among preterm neonates compared with term infants; however, sodium excretion was not significantly different. Pathological proteinuria and high urinary NGAL levels were observed in a number of neonates, which may be indicative of renal injury; however, there was no correlation between the two markers. Findings suggest that neonatal renal function is predominantly influenced by renal maturity, and there was high capacity for postnatal tubular maturation among preterm neonates. There is insufficient evidence to suggest that urinary NGAL is a useful marker of renal injury in the preterm neonate.
Collapse
Affiliation(s)
- Lina Gubhaju
- Preventative Health, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Megan R Sutherland
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Rosemary S C Horne
- Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, Clayton, Victoria, Australia
| | - Alison Medhurst
- Monash Newborn, Monash Medical Centre, Clayton, Victoria, Australia
| | - Alison L Kent
- Department of Neonatology, Canberra Hospital, and the Australian National University Medical School, Canberra, Australian Capital Territory, Australia
| | - Andrew Ramsden
- Monash Newborn, Monash Medical Centre, Clayton, Victoria, Australia
| | - Lynette Moore
- Department of Surgical Pathology, South Australia Pathology, Women's and Children's Hospital, North Adelaide and the University of Adelaide, Adelaide, South Australia, Australia
| | - Gurmeet Singh
- Menzies School of Health Research and the Royal Darwin Hospital, Casuarina, Northern Territory, Australia; and
| | - Wendy E Hoy
- Centre for Chronic Disease, University of Queensland, Brisbane, Queensland, Australia
| | - M Jane Black
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia;
| |
Collapse
|
10
|
Traunmüller F, Popovic M, Konz KH, Vavken P, Leithner A, Joukhadar C. A reappraisal of current dosing strategies for intravenous fosfomycin in children and neonates. Clin Pharmacokinet 2011; 50:493-503. [PMID: 21740073 DOI: 10.2165/11592670-000000000-00000] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The rising incidence of multi-drug resistant bacterial pathogens has renewed interest in the long-known antibacterial fosfomycin. Not least because of its low toxicological potential, there is good clinical experience with intravenous fosfomycin for various Gram-positive and Gram-negative infections in the treatment of children and neonates. However, the current dosing recommendations for intravenous fosfomycin vary widely in paediatric patients. In the present review, we summarized available plasma pharmacokinetic data derived from neonates or children following intravenous administration of fosfomycin. Subsequently, we used this information for recalculation of different dosing strategies and simulated a variety of clinically applied dosing regimens. The percentage of time above the minimal inhibitory concentration (T>MIC) was calculated for each dosing strategy, as this pharmacokinetic-pharmacodynamic parameter was shown to be most predictive of antimicrobial and clinical success of fosfomycin treatment. Our data corroborate the current practice of selecting the dosage of intravenous fosfomycin primarily on the basis of bodyweight and age in paediatric patients. As with other 'time-dependent' antibacterials, a dosing interval of 6-8 hours should be preferred over 12 hours except for immature neonates. Given a T>MIC target of 40-70%, currently recommended dosing strategies appear to be insufficient in children aged 1-12 years, if pathogens with MICs of ≥32 mg/L are suspected and subjects are presenting with normal renal function. Likewise, the lowest recommended daily dose for neonates and infants (aged up to 12 months) of 100 mg/kg bodyweight of fosfomycin should be considered only for pre-term neonates with a postmenstrual age below 40 weeks.
Collapse
|
11
|
Abstract
The differentiation and analysis of urinary proteins has substantially contributed to our knowledge of physiological and pathophysiological processes during glomerular filtration and tubular catabolism of plasma constituents. By use of high-resolution biochemical separation techniques, several urinary polypeptides could be identified as plasma proteins, tissue antigens, tubular enzymes and protein breakdown products. With regard to clinical application, the separation results of conventional gel chromatography and agarose electrophoresis were surpassed by fast protein liquid chromatography and polyacrylamide electrophoresis in one- and two-dimensional systems. In contrast to early one-dimensional polyacrylamide gel electrophoresis (PAGE) methods using homogeneous gels on a macro scale, modern gradient slab gels achieve better resolution over the entire relative molecular mass range of urinary proteins. For clinical demands, the use of micro-scale gradient gels, either laboratory-made or pre-cast, together with an improved Coomassie Brillant Blue staining, offers several advantages, including rapidity, sensitivity and economy. Isoelectric focusing and two-dimensional PAGE, combined with sensitive silver staining and immunoblotting methods, have proved to be valuable tools for the identification and characterization of urinary proteins in defined renal and extra-renal diseases. The quantitative determination of urinary indicator proteins such as albumin and alpha 1- and beta 2-microglobulin can be regarded as a reasonable complement to the pattern diagnosis, especially in the long-term course of renal diseases.
Collapse
Affiliation(s)
- M H Weber
- Zentrum Innere Medizin der Universität Göttingen, F.R.G
| |
Collapse
|