Organic acidurias in Egyptian children: The urge for high-risk screening.

BACKGROUND: Organic acidurias are a group of inborn errors of metabolism. They present a significant diagnostic challenge and are associated with serious morbidity and mortality. They are considered the most frequent inborn errors of metabolism among high-risk children. Gas chromatography-mass spectrometry is a reliable diagnostic technique for organic acidurias. This hospital-based study aimed to quantify the frequency of organic acidurias among a group of high-risk Egyptian pediatric patients and to highlight the importance of high-risk screening for such disorders. METHODS: One hundred and fifty high-risk children who presented to the inherited metabolic disease unit and the pediatric intensive care units of Cairo University Children Hospital were tested for urine organic acids using gas chromatography-mass spectrometry. RESULTS: Thirty percent (45/150) of the patients were confirmed as having an altered organic acids profile. Neurological manifestations were the most common presentation. Glutaric aciduria type I and maple-syrup urine disease were the most common disorders encountered among the group that was studied. CONCLUSION: Organic acid detection by gas chromatography-mass spectrometry is key to the diagnosis of many metabolic disorders. Until a national expanded newborn screening program is established, high-risk screening is strongly encouraged for the early detection of, and proper intervention for such disorders among Egyptian children.

Vitamin D status in Hashimoto's thyroiditis and its association with vitamin D receptor genetic variants.

BACKGROUND: Hashimoto's thyroiditis (HT) is considered the predominant cause of hypothyroidism in iodine sufficient countries. The deficiency of 25-OH-vitamin D3 serum level and the variation of vitamin D receptor (VDR) gene were implicated in a number of autoimmune disorders. This study aimed to test the hypothesis linking between VDR FokI and BsmI variants and HT, in addition to explain their impact on 25-OH-vitamin D3 serum level. MATERIALS AND METHODS: Cross sectional study included 160 hypothyroid subjects, 112 patients with HT and 48 hypothyroid non-HT controls. They were diagnosed based on anti-TPO Ab and or anti-TG Ab results. All cases were subjected to full history taking, thyroid ultrasound examination and a panel of assays (TSH, f.T3, f.T4, anti-TPO Ab, anti-TG Ab, calcium, alkaline phosphatase and phosphate). Serum 25-OH-vitamin D3 was assayed using HPLC-UV method. VDR variants (FokI and BsmI) were genotyped using real-time PCR. RESULTS: FokI AA genotype was statistically higher in HT patients than control group (P value = 0.02) with subsequently higher serum 25-OH-vitamin D3 level in comparison to all other genotypes (P value = 0.039). Serum 25-OH-vitamin D3 level was statistically indifferent between HT and control group (P value = 0.223). A statistically significant increase in total thyroid volume was observed in HT group (P value = 0.002). CONCLUSION: FokI AA genotype is more associated with HT in Egyptian patients compared to hypothyroid non-HT controls. Moreover, patients with FokI AA genotype have statistically higher levels of 25-OH-vitamin D3 suggesting VDR dysfunction even in patients expressing normal level of vitamin D.

The spectrum of bilirubin neurotoxicity in term and near-term babies with hyperbilirubinemia: Does outcome improve with time?

BACKGROUND: While neonatal jaundice is generally a common benign condition; severe hyperbilirubinemia has a devastating potential for brain injury. AIM: To detect the impact of severe neonatal hyperbilirubinemia on motor and mental development and its progress over time in the first year of life using the Bayley scales of infant development (BSID) II. STUDY DESIGN AND PATIENTS: 177 term/near-term infants admitted for neonatal hyperbilirubinemia to the NICU of Cairo University Children's Hospital were enrolled. Clinical examination, BIND score and laboratory tests were performed at admission. Neurodevelopmental assessment using BSIDΙΙ was performed at 3 months for 147/177 neonates, and at 6 months and 12 months for 139/177 neonates. Auditory brainstem evoked potential was recorded at 3 months of age and repeated if abnormal. OUTCOME MEASURES: Psychomotor (PDI) and mental developmental indices (MDI) using BSIDII. Auditory impairment using Auditory Brainstem Response (ABR). RESULTS: TSB levels ranged from 10 to 63 mg/dL (179.6-1077 µmol/L) with a mean of 25.52 ±â€¯6.5 mg/dL (436 ±â€¯112.9 µmol/L) and BIND scores ranged from 0 to 7. By one year of age, 19/139 patients were affected; 8 had classic kernicterus, 3 had isolated auditory impairment, 1 had severe motor and mild mental delay and 7 had mild motor delay. TSB level and BIND score had positive correlation with auditory impairment and lower scores for PDI (which improved with time) and MDI (which remained stationary). Duration of exposure to hyperbilirubinemia negatively affected neurodevelopmental scores. CONCLUSION: The impact of severe hyperbilirubinemia is mainly on motor and auditory impairment. Mild mental delay was detected by BSIDII in few patients. Neurodevelopmental outcome improves over time.

Prediction of 3- to 5-Month Outcomes from Signs of Acute Bilirubin Toxicity in Newborn Infants.

OBJECTIVE: To evaluate the ability of the bilirubin-induced neurologic dysfunction (BIND) score to predict residual neurologic and auditory disability and to document the relationship of BIND score to total serum bilirubin (TSB) concentration. STUDY DESIGN: The BIND score (assessing mental status, muscle tone, and cry patterns) was obtained serially at 6- to 8-hour intervals in 220 near-term and full-term infants with severe hyperbilirubinemia. Neurologic and/or auditory outcomes at 3-5 months of age were correlated with the highest calculated BIND score. The BIND score was also correlated with TSB. RESULTS: Follow-up neurologic and auditory examinations were performed for 145/202 (72%) surviving infants. All infants with severe acute bilirubin encephalopathy (BIND scores 7-9) either died or suffered residual neurologic and auditory impairment. Of 24 cases with moderate encephalopathy (BIND 4-6), 15 (62.5%) resolved following aggressive intervention and were normal at follow-up. Three of 73 infants with mild encephalopathy (BIND scores 1-3) but severe jaundice (TSB ranging 33.5-38 mg/dL; 573-650 µmol/L) had residual neurologic and/or auditory impairment. A BIND score ≥4 had a specificity of 87.3% and a sensitivity of 97.4% for predicting poor neurologic outcomes (receiver operating characteristic analysis). BIND scores trended higher with severe hyperbilirubinemia (r2 = 0.54, P < .005), but 5/39 (13%) infants with TSB ≥36.5 mg/dL (624 µmol/L) had BIND scores ≤3, and normal outcomes at 3-5 months. CONCLUSIONS: The BIND score can be used to evaluate the severity of acute bilirubin encephalopathy and predict residual neurologic and hearing dysfunction.

Eight-year outcomes of 'the Cairo Kidney Centre sequential protocol'.

OBJECTIVES: To describe the long-term results of a previously developed a sirolimus-based sequential immunosuppression protocol for kidney transplant comprising 2 phases: sirolimus + cyclosporine + prednisolone for 3 months followed by sirolimus + prednisolone + mycophenolate mofetil with steroid minimization the first year. Two-year outcomes of patients on this protocol (group A) showed equivalent patient and graft survival, yet with significantly better function, compared with those on cyclosporine + mycophenolate mofetil + prednisolone (group B). MATERIALS AND METHODS: We report the 8-year outcomes in the same cohort (76 patients in group A and 37 in group B). RESULTS: 42% switched from group A to B versus 43% switching from B to A. Intent-to-treat patient survivals at 5 and 8 years were 88% and 85.5% for group A, and 78% and 73% for group B. Death-censored graft survivals were 93% for group A and 95% for group B. Graft function was significantly better at 8 years, with 91% of group A patients compared with 50% in group B having estimated glomerular filtration rates > 45 mL/min/1.73 m2, and a significantly lower incidence of chronic allograft nephropathy in the former. Secondary parameters including blood pressure control, new onset diabetes mellitus, proteinuria and other drug-related adverse events showed no significant differences between the groups. CONCLUSIONS: The sirolimus-based sequential immunosuppression protocol was well tolerated in 58% of patients. The intent-to-treat and patients-ontherapy analyses revealed that it was equivalent to the widely used cyclosporine + mycophenolate mofetil + prednisolone protocol regarding patient and graft survival. It is associated with better graft function and lower incidence of chronic allograft nephropathy in 8 years' follow-up. The incidence of drug-related adverse reactions was not statistically different from those in the comparator.

Serum bilirubin and bilirubin/albumin ratio as predictors of bilirubin encephalopathy.

BACKGROUND AND OBJECTIVE: Bilirubin/albumin ratio (B/A) may provide a better estimate of free bilirubin than total serum bilirubin (TSB), thus improving identification of newborns at risk for bilirubin encephalopathy. The objective of the study was to identify thresholds and compare specificities of TSB and B/A in detecting patients with acute and posttreatment auditory and neurologic impairment. METHODS: A total of 193 term/near-term infants, admitted for severe jaundice to Cairo University Children's Hospital, were evaluated for neurologic status and auditory impairment (automated auditory brainstem response), both at admission and posttreatment by investigators blinded to laboratory results. The relationships of TSB and B/A to advancing stages of neurotoxicity were compared by using receiver operating characteristic curves. RESULTS: TSB and B/A ranged from 17 to 61 mg/dL and 5.4 to 21.0 mg/g, respectively; 58 (30%) of 193 subjects developed acute bilirubin encephalopathy, leading to kernicterus in 35 infants (13 lethal). Auditory impairment was identified in 86 (49%) of 173 infants at admission and in 22 of 128 at follow-up. In the absence of clinical risk factors, no residual neurologic or hearing impairment occurred unless TSB exceeded 31 mg/dl. However, transient auditory impairment occurred at lower TSB and B/A (22.9 mg/dL and 5.7 mg/g, respectively). Intervention values of TSB and B/A set at high sensitivity to detect different stages of neurotoxicity had nearly the same specificity. CONCLUSIONS: Both TSB and B/A are strong predictors of neurotoxicity, but B/A does not improve prediction over TSB alone. Threshold values detecting all affected patients (100% sensitivity) increase with advancing severity of neurotoxicity.

Triple test screening for Down syndrome: an Egyptian-tailored study.

BACKGROUND: The incidence of Down syndrome (DS) in Egypt varies between 1:555 and 1:770 and its screening by triple test is becoming increasingly popular nowadays. Results, however, seem inaccurate due to the lack of Egyptian-specific information needed for risk calculation and a clear policy for programme implementation. Our study aimed at calculation and validation of the triple marker medians used in screening Egyptian females as well as to recommend programme conventions to unify screening in this country. METHODS: The study was conducted on 668 Egyptian women, in weeks 15-20 of pregnancy as proven by sonar. Chorionic gonadotropin (CG), α-fetoprotein (AFP) and unconjugated oestriol (uE3) were measured on Siemens Immulite analyzer. Medians of the three parameters were calculated, regressed against gestational age (GA) and weighted by the number of participants/week. Equations were derived to adjust each parameter to the maternal weight and were centered on the median Egyptian weight. Prisca software was fed with the above data, multiples-of-median (MoM) and DS risks were calculated and the screening performance was evaluated at a mid-trimester risk cutoff of 1:270. RESULTS: Log-linear [AFP/uE3 = 10(A+B*GA)] and exponential equations [CG = A*e (B*GA)] were derived and the regressed medians were found to follow similar patterns to other Asian and Western medians. Oestriol was always lowest (even halved) while CG and AFP were intermediate. A linear reciprocal model best fitted weight distribution among Egyptians and successfully adjusted each parameter to a weight of 78.2 kg. Epidemiological monitoring of these recommendations revealed satisfactory performance in terms of 6.7% initial positive rate and 1.00 grand MoM. CONCLUSIONS: Adoption of the above recommendations is hoped to pave the way to a successful DS screening programme tailored to Egyptian peculiarities.

Validation of a proposed warfarin dosing algorithm based on the genetic make-up of Egyptian patients.

BACKGROUND: Warfarin is the most frequently prescribed oral anticoagulant worldwide. Due to its narrow therapeutic index and inter-patient variability in dose requirement, this drug has been considered an ideal target for personalised medicine. Several warfarin dosing algorithms have been proposed to tailor the warfarin dosage in the European, Asian and African-American populations. However, minimal interest was directed towards Middle East countries. The factors affecting warfarin dose requirement could be different in patients from different geographical and ethnic groups, limiting the value of published dosing algorithms. OBJECTIVE: The first objective of this study was to examine the contribution of genetic and nongenetic factors on the variability of warfarin dose requirements in the Egyptian population using an easy, cost-effective and rapid analysis of vitamin K epoxide reductase complex subunit 1 (VKORC1) and cytochrome P450 (CYP) 2C9 single nucleotide polymorphism (SNP) genotyping of patients. A second objective was to develop and validate an algorithm for warfarin dose prediction that is tailored to Egyptian patients. METHODS: Eighty-four patients, 41 males and 43 females, with a median (25th-75th percentiles) age of 39 (31-48) years were recruited in this study. Fifty patients whose international normalised ratio (INR) was in the range of 2-3 were allocated to a study cohort. SYBR Green-based multiplex allele-specific real-time PCR was used for genotyping of CYP2C9 (1075A>C) and VKORC1 (1173C>T) polymorphisms. Linear regression analysis, including the variables age, gender, CYP2C9 and VKORC1 SNP genotypes, was run to derive the best model for estimating the warfarin dose that achieves an INR of 2-3. The new warfarin dosing algorithm was examined in a second cohort of patients (n=34) to check its validity. The predicted dose requirements for a subgroup of our patients were calculated according to Gage and International Warfarin Pharmacogenetics Consortium (IWPC) algorithms available at http://www.warfarindosing.org. RESULTS: In the study cohort, warfarin dose/week in VKORC1 TT subjects was statistically significantly lower than in VKORC1 CC/CT subjects (p=0.032), while there was no statistically significant difference in warfarin dose/week between CYP2C9*1*1 and *1*3 (p=0.925). A multivariate stepwise linear regression analysis revealed that age and VKORC1 had independent and significant contributions to the overall variability in warfarin dose with a p-value=0.013 and 0.042, respectively. Maintenance dose (mg/week)=65.226-0.422×(age) - 9.474×(VKORC1). The estimated regression equation was able to account for 20.5% of the overall variability in warfarin maintenance dose. A significant positive correlation, with sufficient strength, was observed between the predicted warfarin dose and the actual prescribed dose (r=0.453, p=0.001). In the validation cohort, after application of the dosing algorithm, correlation between predicted and actual dose was statistically significant (p=0.023). The equation was particularly successful among patients with a dose≥35 mg/week. The correlation coefficient between the actual and predicted doses for IWPC and Gage were 0.304 and 0.276, respectively. When compared with our algorithm (r=0.279), the difference was non-significant: p=0.903 and 0.990, respectively. CONCLUSION: VKORC1 (1173C>T) contributes to the warfarin dose variability. Patients' age and genetic variants of VKORC1 account for nearly 20.5% of the variability in warfarin dose required to achieve an INR of 2-3. The success of a prediction equation based on these variables was proved in a different cohort: the predicted dose correlated significantly with the maintenance dose and the equation was more successful among patients with a dose≥35 mg/week. The results of the warfarin algorithm we developed were comparable with those of the IWPC and Gage algorithms with the advantage of using one SNP (VKORC1 1173C>T) only. This represents an economic advantage in our community. Replication of this study in a larger cohort of patients is necessary before translation of this knowledge into clinical guidelines for warfarin prescription.