Levels of cystatin C in low- and high-flux hemodialysis in children with end-stage renal disease.

BACKGROUND: Cystatin-C (CyC) is a middle molecule that is freely filtered at the glomerulus and almost completely reabsorbed by the proximal tubules. The aim of this study was to evaluate serum CyC and its reduction ratio as a biomarker for assessing the adequacy of the hemodialysis (HD) sessions in children with end-stage renal disease on maintenance HD. We also compared levels of CyC in patients on low-flux HD (LFH) and high-flux HD (HFH). METHODS: Forty patients were included in the study and divided into two groups, with one group (16 patients) receiving HFH and the other group receiving LFH (24 patients) (high-flux and low-flux polysulfone filters, respectively). Before and after each dialysis session serum CyC and beta-2-microglobulin (B2M) levels were measured using an ELISA technique, and routine laboratory tests were performed for each patient. RESULTS: Pre-dialytic levels of CyC were significantly lower in the patients receiving HFH than in those receiving LFH (7.33 ± 1.35 vs. 9.73 ± 0.93, respectively; p < 0.0001). In the HFH group, post-dialytic levels of serum CyC were significantly lower than pre-dialytic levels (4.49 ± 0.71 vs. 7.33 ± 1.35, respectively; p < 0.0001). The reduction ratio (RR) of CyC was significantly higher in the HFH group than in the LFH group (38.2 ± 3.91 vs. -6.49 ± 5.05, respectively; p < 0.0001). Serum CyC level significantly correlated with B2M, urea and creatinine levels in both the LFH and HFH groups, whereas its RR significantly correlated with the RRs of urea, creatinine, and B2M in the HFH group. CONCLUSION: The results of our study emphasize the role of CyC as a good marker for assessing the adequacy of HD sessions in children on HFH and show that the CyC RR may be used as an index of middle-molecule toxin clearance following HFH sessions.

The expanded clinical profile and the efficacy of colchicine therapy in Egyptian children suffering from familial Mediterranean fever: a descriptive study.

BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by self-limiting recurrent attacks of fever and serosal inflammation, leading to abdominal, thoracic or articular pain. OBJECTIVE: To detect variable clinical presentations and genotypic distribution of different groups of FMF patients and the efficacy of colchicine therapy in treatment of these groups of FMF after one year. METHODS: A cross-sectional study was conducted on 70 patients already diagnosed with FMF and following-up at the Rheumatology Clinic, Children's Hospital - Cairo University. Diagnosis of FMF was determined according to Tel Hashomer criteria for FMF. All patients were subjected to a questionnaire including detailed history with emphasis on clinical manifestations and colchicine dose to control attacks. Mutational analysis was performed for all study subjects covering 12 mutations in the MEFV gene: E148Q, P369S, F479L, M680I (G/C), M680I (G/A), I692del, M694V, M694I, K695R, V726A, A744S and R761H. Response to colchicine treatment was evaluated as complete, incomplete and unresponsive. RESULTS: Out of the 70 patients- 40 males and 30 females- fever was the most common presenting feature, followed by abdominal pain, and arthritis; documented in 95.7%, 94.3%, and 77.1% of cases respectively. Mutational analysis detected gene mutation on both alleles in 20 patients (homozygotes), on only 1 allele in 40 patients (heterozygotes), and on none of the alleles (uncharacterized cases). Mild to moderate disease severity score (according to Tel Hashomer key to severity score) was detected in a significant proportion of heterozygotes and the uncharacterized group than the homozygotes. All patients received colchicine therapy; 22.9% of them showed complete response, 74.3% showed incomplete response and 2.9% showed no response to therapy. The colchicine dose needed to control attacks was significantly lower in heterozygotes than the homozygotes(P=0.04). Also patients' response to colchicine therapy was significantly better in the heterozygous group(P=0.023). CONCLUSION: Fever, abdominal pain and arthritis are the most common presenting features for homozygous, Heterozygous and uncharacterized patients. E148Q, V726A, and M680I were the most common mutations detected in the heterozygous group. Homozygosity were found for M680I, M694V, and M694I mutations in 13 patients (65% of homozygotes). Heterozygotes presenting with severe phenotype should be further analyzed for less common second MEFV mutation using gene sequencing. The colchicine dose required to control the attacks was significantly lower and patients' response to colchicine therapy was significantly better in the heterozygous group than homozygous group.

Plasma neutrophil gelatinase-associated lipocalin as an early biomarker for prediction of acute kidney injury after cardio-pulmonary bypass in pediatric cardiac surgery.

INTRODUCTION: Cardiopulmonary bypass (CPB) surgery is considered one of the most frequent surgical procedures in which acute kidney injury (AKI) represents a frequent and serious complication. The aim of the present study was to evaluate the efficiency of neutrophil gelatinase-associated lipocalin (NGAL) as an early AKI biomarker after CPB in pediatric cardiac surgery. MATERIAL AND METHODS: The study included forty children aged 2 to 78 months undergoing CPB. They were divided into group I: patients who suffered AKI grades II and III; and group II: patients who did not develop AKI or at risk. Peripheral venous blood was withdrawn pre- and post-operatively for serial measurements of NGAL and creatinine. Statistical analysis was performed using Statistical Package for Social Sciences version 14. RESULTS: Mean plasma NGAL levels showed highly significant elevations in group I patients at 2, 12, and 24 h after surgery (p < 0.0001) compared to group II. Significant correlations were found between NGAL and creatinine at different time intervals. Highly significant correlations (p < 0.0001) were found between plasma NGAL and AKI at 2, 12 and 24 h after surgery. A cut-off level of 100 ng/ml at 2 h, and 125 ng/ml at 12 h post-operatively both recorded the highest accuracy, being 95% accurate, with sensitivity of 100% and 89.5% respectively, and specificity of 90.5% and 100% respectively. CONCLUSIONS: This study showed that plasma NGAL could be used as an early biomarker for detection of AKI following CPB. We recommend further studies on a wider scale to validate the current study results.