Product of serum calcium and phosphorus (Ca × PO4) as predictor of cardiovascular disease risk in predialysis patients. Clin Biochem. 2014;47:77-81. [PMID: 24064489 DOI: 10.1016/j.clinbiochem.2013.09.012]

Extensive myocardial calcifications in a dialysis patient: A porcelain heart manifesting with abdominal pain

This case report describes a 41-year-old male patient with chronic kidney disease on peritoneal dialysis presenting with upper abdominal pain and mild thigh numbness. CT chest demonstrated extensive myocardial calcifications and left atrial thrombus. This case emphasizes the clinical relevance of myocardial calcifications, especially in patients with end-stage renal disease. It also highlights the potential association between these calcifications and complications such as atrial fibrillation and thromboembolic events. The findings emphasize the need for diagnostic vigilance and an improved understanding of the pathophysiology of myocardial calcifications in the context of renal disease.

Prognostic models for chronic kidney disease: a systematic review and external validation

BACKGROUND

Accurate risk prediction is needed in order to provide personalized healthcare for chronic kidney disease (CKD) patients. An overload of prognosis studies is being published, ranging from individual biomarker studies to full prediction studies. We aim to systematically appraise published prognosis studies investigating multiple biomarkers and their role in risk predictions. Our primary objective was to investigate if the prognostic models that are reported in the literature were of sufficient quality and to externally validate them.

METHODS

We undertook a systematic review and appraised the quality of studies reporting multivariable prognosis models for end-stage renal disease (ESRD), cardiovascular (CV) events and mortality in CKD patients. We subsequently externally validated these models in a randomized trial that included patients from a broad CKD population.

RESULTS

We identified 91 papers describing 36 multivariable models for prognosis of ESRD, 50 for CV events, 46 for mortality and 17 for a composite outcome. Most studies were deemed of moderate quality. Moreover, they often adopted different definitions for the primary outcome and rarely reported full model equations (21% of the included studies). External validation was performed in the Multifactorial Approach and Superior Treatment Efficacy in Renal Patients with the Aid of Nurse Practitioners trial (n = 788, with 160 events for ESRD, 79 for CV and 102 for mortality). The 24 models that reported full model equations showed a great variability in their performance, although calibration remained fairly adequate for most models, except when predicting mortality (calibration slope >1.5).

CONCLUSIONS

This review shows that there is an abundance of multivariable prognosis models for the CKD population. Most studies were considered of moderate quality, and they were reported and analysed in such a manner that their results cannot directly be used in follow-up research or in clinical practice.

Early predictors of cardiac dysfunction in Egyptian children with chronic kidney disease

Background:

Cardiovascular morbidity (CVM) is the main etiology of mortality in children and adolescents with chronic kidney disease (CKD). CKD associated cardiovascular mortality is more common in children with diastolic cardiac dysfunction which was considered as an early indicator for death, while increased left ventricular mass (LVM) is a strong independent risk factor for these patients. Vitamin D deficiency was previously studied as one of the risk factors for CVM.

Aim:

The aim of the work was to investigate the relationship between biomarkers of mineral bone disorder including serum 25(OH) Vitamin D3 (25-OH D3), phosphorus and calcium × phosphorus (Ca×Po4) product with diastolic cardiac function and LVM in children and adolescents with CKD.

Subjects and Methods:

This was a cross-sectional observational study. Participants were classified into two groups: Group I including 86 pediatric patients with CKD (stages 4 or 5) and Group II including 40 healthy controls. Group I was subdivided into IA included children with diastolic dysfunction and IB included cases without diastolic dysfunction. 25-OH D3 level was measured by enhanced chemiluminescence method and intact parathyroid hormone (iPTH) by electrochemiluminescence method. Parameters for diastolic function and LVM were assessed by Doppler echocardiography, tissue Doppler imaging, and M-mode echocardiography.

Results:

25-OH D3 level was significantly lower in Group I when compared to Group II. Diastolic dysfunction was present in 48.8% of the studied patients and was significantly associated with increased serum phosphorus and calcium-phosphorus product but not with decreased level of 25-OH D3. There was a significant positive correlation between LVM and iPTH.

Conclusions:

Hyperphosphatemia and high Ca×Po4 product were considered of prognostic value as they predict early diastolic dysfunction and increased LVM in children with CKD.

Working Toward an Improved Understanding of Chronic Cardiorenal Syndrome Type 4

Chronic diseases of the heart and of the kidneys commonly coexist in individuals. Certainly combined and persistent heart and kidney failure can arise from a common pathologic insult, for example, as a consequence of poorly controlled hypertension or of severe diffuse arterial disease. However, strong evidence is emerging to suggest that cross talk exists between the heart and the kidney. Independent processes are set in motion when kidney function is chronically diminished, and these processes can have distinct adverse effects on the heart. The complex chronic heart condition that results from chronic kidney disease (CKD) has been termed cardiorenal syndrome type 4. This review will include an updated description of the cardiac morphology in patients who have CKD, an overview of the most likely CKD-sourced culprits for these cardiac changes, and the potential therapeutic strategies to limit cardiac complications in patients who have CKD.

Determination of serum calcium levels by 42Ca isotope dilution inductively coupled plasma mass spectrometry

Background: Serum calcium level is an important clinical index that reflects pathophysiological states. However, detection accuracy in laboratory tests is not ideal; as such, a high accuracy method is needed.

Methods:

We developed a reference method for measuring serum calcium levels by isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS), using 42Ca as the enriched isotope. Serum was digested with 69% ultrapure nitric acid and diluted to a suitable concentration. The 44Ca/42Ca ratio was detected in H2 mode; spike concentration was calibrated by reverse IDMS using standard reference material (SRM) 3109a, and sample concentration was measured by a bracketing procedure. We compared the performance of ID ICP-MS with those of three other reference methods in China using the same serum and aqueous samples.

Results:

The relative expanded uncertainty of the sample concentration was 0.414% (k=2). The range of repeatability (within-run imprecision), intermediate imprecision (between-run imprecision), and intra-laboratory imprecision were 0.12%–0.19%, 0.07%–0.09%, and 0.16%–0.17%, respectively, for two of the serum samples. SRM909bI, SRM909bII, SRM909c, and GBW09152 were found to be within the certified value interval, with mean relative bias values of 0.29%, −0.02%, 0.10%, and −0.19%, respectively. The range of recovery was 99.87%–100.37%. Results obtained by ID ICP-MS showed a better accuracy than and were highly correlated with those of other reference methods.

Conclusions:

ID ICP-MS is a simple and accurate candidate reference method for serum calcium measurement and can be used to establish and improve serum calcium reference system in China.

Cardiorenal Syndrome and the Role of the Bone-Mineral Axis and Anemia

The association between chronic kidney disease (CKD) and cardiovascular disease (CVD) is well established, and there is mounting evidence of interorgan cross talk that may accelerate pathologic processes and the progression of organ dysfunction in both systems. This process, termed cardiorenal syndrome (CRS) by the Acute Dialysis Quality Initiative, is considered a major health problem: patients with CKD and CVD are at much higher risk of mortality than patients with either condition alone. To date, the majority of CRS research has focused on neurohormonal mechanisms and hemodynamic alterations. However, mounting evidence suggests that abnormalities in the normal pathophysiology of the bone-mineral axis, iron, and erythropoietin play a role in accelerating CKD and CVD. The goal of this article is to review the role and interrelated effects of the bone-mineral axis and anemia in the pathogenesis of chronic CRS.

Differential gene expression profiles between ulcerative colitis and Crohn's disease

AIM: To compare the difference in gene expression profiles between ulcerative colitis and Crohn's disease to provide a theoretical basis for further understanding of their pathogenesis and clinical treatment of choice.

METHODS: Intestinal epithelial cells from patients with Crohn's disease, those with ulcerative colitis and healthy volunteers were subjected to microarray analysis to obtain their gene expression profiles. Linear regression model was built using the Limma package to compare differences in gene expression between different groups. Gene Ontology (GO) analysis was performed to predict gene function, and cluster Profiler was used to conduct enrichment analysis of gene clusters. KEGG pathway analysis was performed to obtain the similarities and differences in pathways between Crohn's disease and ulcerative colitis.

RESULTS: Differential gene expression profiles were obtained between ulcerative colitis, Crohn's disease and normal controls by microarray analysis. GO analysis showed that ulcerative colitis and Crohn's disease had significant differences in gene expression. KEGG pathway analysis indicated that ulcerative colitis and Crohn's disease had significant differences in cell adhesion molecules (CAMs), ECM-receptor interaction, B cell receptor signaling pathway, and cytokine-cytokine receptor interaction.

CONCLUSION: There are thousands of differentially expressed genes between ulcerative colitis and Crohn's disease. The two diseases have significant differences in intracellular pathways, particularly metabolism, and differential metabolites may be used to distinguish the two diseases.