Homozygous c.130-131 ins A (pW44X) mutation in the HAX1 gene as the most common cause of congenital neutropenia in Turkey: Report from the Turkish Severe Congenital Neutropenia Registry

BACKGROUND

Severe congenital neutropenia is a rare disease, and autosomal dominantly inherited ELANE mutation is the most frequently observed genetic defect in the registries from North America and Western Europe. However, in eastern countries where consanguineous marriages are common, autosomal recessive forms might be more frequent.

METHOD

Two hundred and sixteen patients with severe congenital neutropenia from 28 different pediatric centers in Turkey were registered.

RESULTS

The most frequently observed mutation was HAX1 mutation (n = 78, 36.1%). A heterozygous ELANE mutation was detected in 29 patients (13.4%) in our cohort. Biallelic mutations of G6PC3 (n = 9, 4.3%), CSF3R (n = 6, 2.9%), and JAGN1 (n = 2, 1%) were also observed. Granulocyte colony-stimulating factor treatment was given to 174 patients (80.6%). Two patients died with infectious complications, and five patients developed myelodysplastic syndrome/acute myeloblastic leukemia. The mean (± mean standard error) follow-up period was 129.7 ± 76.3 months, and overall survival was 96.8% (CI, 94.4-99.1%) at the age of 15 years. In Turkey, severe congenital neutropenia mostly resulted from the p W44X mutation in the HAX1 gene.

CONCLUSION

In Turkey, mutation analysis should be started with HAX1, and if this is negative, ELANE and G6PC3 should be checked. Because of the very high percentage of consanguineous marriage, rare mutations should be tested in patients with a negative mutation screen.

Glomerular and tubular functions in children with different forms of beta thalassemia

BACKGROUND

Although there are many available data about renal involvement in patients with beta thalassemia major (TM), the changes in renal functions of other types, such as thalassemia intermedia (TI) and thalassemia minor (TMin), were reported less. Therefore, we aimed to evaluate renal tubular and glomerular functions in patients with three types of beta thalassemia.

METHODS

This prospective case-control study was conducted on 118 beta-thalassemia patients (49 in TM, 18 in TI and 51 TMin) and 51 healthy controls. Glomerular functions [estimated glomerular filtration rate (GFR), serum cystatin C and urinary protein creatinine ratio] and tubular functions [fractioned sodium excretion (FENa), tubular reabsorption of phosphorus, urinary excretion of uric acid, levels of retinol-binding protein, alpha-1 macroglobulin (alpha-1M), and beta-2 microglobulin, calcium creatinine ratio] were assessed in all patients and controls.

RESULTS

The mean ages of the groups and controls at presentation were similar. Although GFR was similar in all patients and control groups, serum levels of cystatin C in patients with TM and TI were significantly higher compared to TMin and controls. Alpha-1M, FENa, urinary excretion of uric acid, and urine protein/creatinine ratio in TM and TI groups were significantly higher than the others. Mean cystatin C level was also higher in patients with TMin compared the controls. However, there were no significant differences according to all tubular and other glomerular functions between TMin and control groups.

CONCLUSIONS

Although all types of beta thalassemia patients should be closely monitored to prevent further decrease in renal functions, the patients with TI should be considered to have a higher risk of glomerular and tubular deterioration as well as TM.

ALL-BFM 95 treatment in Turkish children with acute lymphoblastic leukemia--experience of a single center

Little is known about the likelihood of curing children with high-dose chemotherapy regimens for treatment of childhood acute lymphoblastic leukemia (ALL) in Turkey. The authors here report their 13 years' experience with original ALL-BFM (Berlin-Franfurt-Münster) 95 protocol in a cohort of 140 Turkish children with ALL. Complete remission rate was 97.7% with a relapse rate of 12.9% and death rate 17.9% during a median follow-up of 69 months. The event-free survival (EFS), disease-free survival (DFS), and overall survival (OS) in these patients at 12 years were 75.0%, 87.1%, and 80.6%, respectively. These results show that ALL-BFM 95 protocol is equally applicable in the experienced centers, even in developing countries without substantial treatment-related toxicity. High rate of infection deaths are to be reduced with correct policies.

Invasive fungal infections in pediatric leukemia patients receiving fluconazole prophylaxis

BACKGROUND

Children with acute leukemia have increased risk for invasive fungal infections (IFI) but the role of long term antifungal prophylaxis (AFP) in morbidity and mortality of IFI is not well-known.

PROCEDURE

Medical records of 154 children with acute leukemia who received AFP with fluconazole during intensive chemotherapy were retrospectively reviewed to determine risk factors, clinical characteristics and outcome of IFI.

RESULTS

The overall incidence of IFI was 13.6%. Frequencies of proven, probable and possible infections were 7.2%, 2.6%, and 3.8%, respectively. The causative agent was Candida in 12 (57.2%) and Aspergillus in 9 (42.8%) children. There were 10 children with candidemia (47.6%), 7 with pulmonary aspergillosis (33.4%), 2 with hepatosplenic candidiasis (10.0%), one with sinopulmonary aspergillosis (4.5%) and one with sinus aspergillosis (4.5%). IFI was twice as common in acute myeloid leukemia (AML) (20.7%) than in acute lymphoblastic leukemia (ALL) (10.2%). Duration of profound neutropenia (P = 0.01) and steroid medications (P = 0.001) were significantly associated with IFI in univariate but not in multivariate analysis. Liposomal amphotericin B (L-AMB) was successful in 15 of 21 children as a single agent. Voriconazole produced complete response in four children with invasive aspergillosis and two with hepatosplenic candidiasis, who were unresponsive to L-AMB. The rate of IFI attributable death was 5%.

CONCLUSIONS

Our results indicate that AFP with fluconazole and early empirical antifungal therapy may be effective in reducing the incidence and mortality of IFI in children with acute leukemia.

Bilateral leukocoria in infant with afibrinogenemia

PURPOSE

To report a bilateral leukocoria case in a patient suffering from afibrinogenemia.

METHODS

An observational case where congenital afibrinogenemia was presented with bilateral retinal and vitreous hemorrhages that proceeded to vitreoretinal surgery was presented. In addition, complete ophthalmic and radiological examinations and vitreoretinal surgery were performed.

RESULTS

Right eye had a complete recovery while the left eye showed serious proliferative vitreoretinopathy and shortened retina. Three years after the surgery clinical examination showed that the right eye was aphacic with an attached retina and clear ocular media while the left eye was phtysic.

CONCLUSION

We recommend broad clotting profile for infants suffering from vitreous or retinal hemorrhages with no obvious physical abuse. Our present case furthermore implies that afibrinogenemia can lie beneath the pathogenesis of bilateral leukocoria and should alert physician for the presence of an afibrinogenemia among several types of bleeding predispositions.

Evaluation of clinical characteristics, diagnosis and management in childhood immune thrombocytopenic purpura: a single center's experience

Diagnostic evaluation and management in childhood immune thrombocytopenic purpura (ITP) are controversial. We reviewed the files of 162 children with ITP to evaluate clinical characteristics, response to treatment and outcome. History of antecedent infection, vaccination and serologic evidence for acute viral infection were present in 48%, 5% and 17% of the patients, respectively. At diagnosis, two-thirds of the patients had a platelet count of <10,000/microl but only 10% had major bleedings. Intracranial hemorrhage was seen in two patients (1.2%) with a mortality rate of 0.6%. Sixteen percent developed chronic ITP. The rate of platelet recovery with mega-dose methylprednisolone (30 mg/kg/d for 3 and 20 mg/kg/d for 4 days) was similar to that obtained with intravenous immunoglobulin or oral prednisolone. Four of seven patients with ITP responded to splenectomy. These data show that mode of treatment has no effect on the clinical course and prognosis of childhood ITP.

Breast milk leptin: its relationship to maternal and infant adiposity

BACKGROUND AND AIMS

Leptin, the product of the obese gene (ob), is synthesized by adipose tissue and contributes to the regulation of energy homeostasis and food intake. Recently, immunoreactive leptin was reported to be present in human milk. The objective was to determine if there was a relation between breast milk leptin concentrations and adiposity in exclusively breast-fed infants.

METHODS

Fifty healthy, exclusively breast-fed infants beyond neonatal period, and their mothers were included into the study. Infants whose weight-for-length was above the 90th percentile were defined as obese (n=17), and non-obese if the weight for length between 20-90th percentile (n=33). Anthropometric measurements of infants and mothers were also made and breast milk samples were analyzed for leptin.

RESULTS

There was no significant difference between breast milk leptin concentrations of obese and non-obese infants' mothers. Breast milk leptin concentrations were significantly correlated with mothers' body mass index when all subjects analyzed. There was no significant correlation between breast milk leptin concentrations and body mass index of infants.

CONCLUSIONS

Leptin concentrations of human milk are not different in the mothers of obese and non-obese infants. These findings suggests that milk-borne leptin has no significant effect on adiposity during infancy.

Guillain-Barré syndrome in a child with acute lymphoblastic leukemia

A 4-year-old boy with acute lymphoblastic leukemia receiving maintenance treatment developed quadriparesis, facial palsy, difficulty in swallowing, and hypertension following a respiratory infection and candida septicemia. Examination of the cerebrospinal fluid was normal initially but later showed albuminocytologic dissociation, the characteristic finding of Guillain-Barré syndrome. Complete recovery occurred after treatment with intravenous immunoglobulin. Differential diagnosis of Guillain-Barré syndrome from vincristine toxicity in patients with leukemia and possible association with the infections are discussed.

Excitatory amino acids and taurine levels in cerebrospinal fluid of hypoxic ischemic encephalopathy in newborn

The recent studies indicating the transiently enhanced expression of excitatory amino acid receptors in hypoxia vulnerable brain regions and the elevated concentration of aspartate and glutamate in cerebrospinal fluid of asphyxiated newborns strongly suggest the role of excitatory amino acids in hypoxic ischemic brain damage in the developing human brain. In this study, we compared the concentrations of glutamate, aspartate, taurine and glycine in the cerebrospinal fluid of asphyxiated infants with values of a healthy control group. The concentrations of aspartate (5.82 +/- 3.36), glutamate (1.76 +/- 1.0) and taurine (9.32 +/- 9.1) were significantly elevated in cerebrospinal fluid of asphyxiated infants (P < 0.05). When compared to the control group, the high levels of aspartate was correlated with the degrees of hypoxic-ischemic encephalopathy (HIE) and the varying outcome. The high levels of aspartate and glutamate in the asphyxiated patients adds further evidence to the role of excitotoxicity in hypoxic ischemic encephalopathy. The mental and motor development of the patients in asphyxiated group was followed for 3 years.

Role of excitatory aminoacids in neonatal hypoglycemia

BACKGROUND

In many neurological disorders, injury to neurons may be due in part to overstimulation of the receptors for the excitatory amino acids glutamate and aspartate. The same excitotoxic mechanism and high aspartate levels in experimental studies led to this study of the concentrations of glutamate and aspartate and zinc, copper, and magnesium levels in the cerebrospinal fluid (CSF) of hypoglycemic newborns.

METHODS

Aspartate and glutamate were determined by high-performance liquid chromatography, and magnesium, zinc and copper by atomic absorption spectrophotometer.

RESULTS

The CSF levels of aspartate (3.98 +/- 1.77 mumol/L) and glutamate (1.7 +/- 1.05 mumol/L) in 20 hypoglycemic newborns were significantly higher when compared with the values of aspartate (2.19 +/- 0.6 mumol/L) and glutamate (0.77 +/- 0.34 mumol/L) of 10 control newborns. In the hypoglycemic patients, the concentration of zinc (0.57 +/- 0.13 microgram/mL), but not copper (0.39 +/- 0.40 microgram/mL) was significantly lower when compared with the control values. There was no difference in the magnesium levels between the two groups.

CONCLUSIONS

The higher levels of excitatory amino acids found in the CSF of hypoglycemic infants than in controls were consistent with previous animal studies, which may indicate the role of excitatory amino acids in the late biochemical effects of hypoglycemia in newborn brain metabolism.