Laboratory diagnostics of chronic kidney disease in Croatia: state of the art

Introduction: Early identification and management of chronic kidney disease (CKD) is highly cost-effective and can reduce the risk of kidney failure progression and cardiovascular disease. In 2014, the Joint Croatian Working Group (JCWG) for laboratory diagnostic of CKD on the behalf of Croatian society of medical biochemistry and laboratory medicine (CSMBLM) and Croatian chamber of medical biochemists (CCMB) conducted a survey across Croatian medical-biochemistry laboratories to assess the current practice in this area of laboratory medicine. The aim of this study was to present the data collected through the survey and to give insight about laboratory diagnostics of chronic kidney disease in Croatia. Materials and methods: An invitation to participate in the survey was sent to all Croatian medical-biochemistry laboratories (N = 196). The questionnaire was designed in a form of questions and statements, with possible multiple answers, comprising 24 questions. Results: The response rate was 80/196 (40.8%). 39 answers were from primary medical-biochemistry laboratories. 31/78 (0.40) laboratories measure creatinine with non-standardized method (uncompensated Jaffe method). 58/78 (0.74) of laboratories that measure creatinine do not report eGFR values. Similar number of laboratories (58/80, 0.73) do not measure urine albumin or protein. Conclusions: There is a large heterogeneity among Croatian laboratories regarding measuring methods, reporting units and reference intervals (cut-off values), both for creatinine and urine albumin or protein. The two key prerequisites for CKD screening, automatic reporting of eGFR and albuminuria or proteinuria assessment, are not implemented nationwide. There is a need for harmonization in laboratory diagnostics of CKD in Croati

sbcB15 and ΔsbcB Mutations Activate Two Types of RecF Recombination Pathways in Escherichia coli

Escherichia coli cells with mutations in recBC genes are defective for the main RecBCD pathway of recombination and have severe reductions in conjugational and transductional recombination, as well as in recombinational repair of double-stranded DNA breaks. This phenotype can be corrected by suppressor mutations in sbcB and sbcC(D) genes, which activate an alternative RecF pathway of recombination. It was previously suggested that sbcB15 and ΔsbcB mutations, both of which inactivate exonuclease I, are equally efficient in suppressing the recBC phenotype. In the present work we reexamined the effects of sbcB15 and ΔsbcB mutations on DNA repair after UV and γ irradiation, on conjugational recombination, and on the viability of recBC (sbcC) cells. We found that the sbcB15 mutation is a stronger recBC suppressor than ΔsbcB, suggesting that some unspecified activity of the mutant SbcB15 protein may be favorable for recombination in the RecF pathway. We also showed that the xonA2 mutation, a member of another class of ExoI mutations, had the same effect on recombination as ΔsbcB, suggesting that it is an sbcB null mutation. In addition, we demonstrated that recombination in a recBC sbcB15 sbcC mutant is less affected by recF and recQ mutations than recombination in recBC ΔsbcB sbcC and recBC xonA2 sbcC strains is, indicating that SbcB15 alleviates the requirement for the RecFOR complex and RecQ helicase in recombination processes. Our results suggest that two types of sbcB-sensitive RecF pathways can be distinguished in E. coli, one that is activated by the sbcB15 mutation and one that is activated by sbcB null mutations. Possible roles of SbcB15 in recombination reactions in the RecF pathway are discussed

The role of laboratory testing in detection and classification of chronic kidney disease: national recommendations

Chronic kidney disease (CKD) is a common clinical condition with significant adverse consequences for the patient and it is recognized as a significant public health problem. The role of laboratory medicine in diagnosis and management of CKD is of great importance: the diagnosis and staging are based on estimation of glomerular filtration rate (eGFR) and assessment of albuminuria (or proteinuria). Therefore, the joint working group of the Croatian society of medical biochemistry and laboratory medicine and Croatian chamber of medical biochemists for laboratory diagnostics in CKD issued this national recommendation regarding laboratory diagnostics of CKD. Key factors for laboratories implementing the national guidelines for the diagnosis and management of CKD are: 1. Ensure good communication between laboratory professionals and clinicians, such as nephrologists or specialists in general/family medicine, 2. Ensure all patients are provided with the same availability of laboratory diagnostics, 3. Ensure creatinine assays are traceable to isotope dilution mass spectrometry (IDMS) method and have minimal bias and acceptable imprecision, 4. Select the appropriate GFR estimating formula. Recommended equation is the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD – EPI) equation, 5. In reporting the key laboratory tests (creatinine, eGFR, urine albumin-to-creatinine ratio, urine protein-to-creatinine ratio) use the appropriate reporting units, 6. Provide adequate information on limitations of creatinine measurement. The manuscript has been organized to identify critical points in laboratory tests used in basic laboratory diagnostics of CKD and is based on the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease

National Guidelines for the Performance of the Sweat Test in Diagnosis of Cystic Fibrosis on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine and the Cystic Fibrosis Centre - Paediatrics and adults, University Hospital Centre Zagreb

The sweat test (ST) is a cornerstone in the diagnosis of cystic fibrosis (CF), together with newborn screening and genetic testing. However, the performance of the ST can depend on the operator’s skill, so several international guidelines have been published to standardise the ST, but inconsistencies remain. The joint Working Group for ST Standardisation (WG STS) of the Croatian Society of Medical Biochemistry and Laboratory Medicine, in association with cistic fybrosis health professional and the Cistic Fibrosis Centre for Paediatrics and Adults, have issued National Guidelines for the Performance of the Sweat Test in order to ensure consistency in ST performance and accuracy of reported results. Many of the standards were taken from the 2nd Edition of the UK Guidelines for Performance of the ST for the Diagnosis of CF, while others were taken from independent consensus statements from the WG STS based on local ST equipment and practices. The standards cover every step of the ST, from the indications for testing to reporting of results and their interpretation, including the analytical phase and quality control. In addition, National Guidelines include appendices with practical examples in order to aid implementation of the recommendations in routine practice