The role of complement in Streptococcus pneumoniae-associated haemolytic uraemic syndrome.

BACKGROUND: Atypical forms of haemolytic uraemic syndrome (aHUS) include HUS caused by defects in the regulation of alternative complement pathway and HUS linked to neuraminidase-producing pathogens, such as Streptococcus pneumoniae. Increasing data support a pathogenic role of neuraminidase in the development of S. pneumoniae-associated haemolytic uraemic syndrome (SP-HUS), but the role of complement has never been clarified in detail. Therefore, we aimed to investigate whether the pathologic complement profile and genetic risk factors of aHUS are present in patients with SP-HUS. METHODS: Enrolling five patients with SP-HUS classical and alternative pathway activity, besides C3, C4, factors H, B, I and anti-factor H autoantibody levels were determined. The coding regions of CFH, CFI, CD46 (MCP), THBD, C3 and CFB genes were sequenced and the copy number of CFI, CD46, CFH and related genes were also analyzed. RESULTS: We found that in the acute phase samples of SP-HUS patients, complement components C4, C3 and activity of the classical and alternative pathways were decreased, indicating severe activation and complement consumption, but most of these alterations normalized later in remission. Three of the patients carried mutations and risk haplotypes in complement-mediated aHUS associated genes. The identified mutations include a previously published CFI variant (P50A) and two novel ones in CFH (R1149X) and THBD (T44I) genes. CONCLUSIONS: Our results suggest that severe complement dysregulation and consumption accompany the progress of invasive pneumococcal disease (IPD)-associated SP-HUS and genetic variations of complement genes may contribute to the development of this complication in a proportion of the affected patients.

Different administration schedules of darbepoetin alfa affect oxidized and reduced glutathione levels to a similar extent in 5/6 nephrectomized rats.

BACKGROUND: The development of erythropoiesis-stimulating agents (ESAs) with extended serum half-lives has allowed marked prolongation of the administration intervals. The level of oxidative stress is increased in chronic kidney disease, and is reportedly decreased after long-term ESA treatment. However, the effect of different dosing regimens of ESAs on oxidative stress has not been elucidated. METHODS: Five-sixths nephrectomized (NX) rats received either 0.4 µg/kg darbepoetin alfa (DA) weekly or 0.8 µg/kg DA fortnightly between weeks 4 and 10. NX animals receiving saline and a sham-operated (SHAM) group served as controls. The levels of oxidized and reduced glutathione (GSSG, GSH) were followed from blood samples drawn fortnightly. RESULTS: During the follow-up, the ratios GSSG/GSH showed similar trends in both DA groups, levels being significantly lower than those in the SHAM group at weeks 8 and 10. GSSG levels were lower than the baseline throughout the study in all groups except for NX controls. The GSH levels were increased in all three NX groups (weeks 6-10) compared with both the baseline and the SHAM group CONCLUSION: Our results suggest that the extent of oxidative stress is similar in response to different dosing regimens of DA in 5/6 NX rats when comparable hemoglobin levels are maintained. These findings remain to be confirmed in chronic kidney disease patients.

Age-dependent parathormone levels and different CKD-MBD treatment practices of dialysis patients in Hungary--results from a nationwide clinical audit.

BACKGROUND: Achieving target levels of laboratory parameters of bone and mineral metabolism in chronic kidney disease (CKD) patients is important but also difficult in those living with end-stage kidney disease. This study aimed to determine if there are age-related differences in chronic kidney disease-mineral and bone disorder (CKD-MBD) characteristics, including treatment practice in Hungarian dialysis patients. METHODS: Data were collected retrospectively from a large cohort of dialysis patients in Hungary. Patients on hemodialysis and peritoneal dialysis were also included. The enrolled patients were allocated into two groups based on their age (<65 years and ≥65 years). Characteristics of the age groups and differences in disease-related (epidemiology, laboratory, and treatment practice) parameters between the groups were analyzed. RESULTS: A total of 5008 patients were included in the analysis and the mean age was 63.4±14.2 years. A total of 47.2% of patients were women, 32.8% had diabetes, and 11.4% were on peritoneal dialysis. Diabetes (37.9% vs 27.3%), bone disease (42.9% vs 34.1%), and soft tissue calcification (56.3% vs 44.7%) were more prevalent in the older group than the younger group (p<0.001 for all). We found an inverse relationship between age and parathyroid hormone (PTH) levels (p<0.001). Serum PTH levels were lower in patients with diabetes compared with those without diabetes below 80 years (p<0.001). Diabetes and age were independently associated with serum PTH levels (interaction: diabetes × age groups, p=0.138). Older patients were more likely than younger patients to achieve laboratory target ranges for each parameter (Ca: 66.9% vs 62.1%, p<0.001; PO4: 52.6% vs 49.2%, p<0.05; and PTH: 50.6% vs 46.6%, p<0.01), and for combined parameters (19.8% vs 15.8%, p<0.001). Older patients were less likely to receive related medication than younger patients (66.9% vs 79.7%, p<0.001). CONCLUSIONS: The achievement of laboratory target ranges for bone and mineral metabolism and clinical practice in CKD depends on the age of the patients. A greater proportion of older patients met target criteria and received less medication compared with younger patients.

Congenital myasthenic syndromes and transient myasthenia gravis.

Hypotonia in the neonatal period and early infancy is a common clinical finding. It can be caused by various heterogeneous disorders of different origin which might lead to diagnostic difficulties. Disorders of the neuromuscular junction, such as congenital myasthenic syndromes and neonatal transient myasthenia gravis are among the aetiologies. We report on a case of congenital myasthenia caused by mutation in the long cytoplasmic loop of the epsilon subunit of the acetylcholine receptor and a neonate of a myasthenic mother diagnosed with transient myasthenia gravis.

The fate of tyrosinaemic Hungarian patients before the NTBC aera.

Before the introduction of the NTBC treatment (Orfadine) from two tyrosinemic Hungarian families 1-3 tyrosinemic homozygous male patients died of hepatocellular carcinoma and one patient of hepatocellular carcinoma combined with clear cell renal adenocarcinoma. From the third tyrosinemic family one homozygous girl patient has been treated with NTBC (Orfadine), IMTV-AM, she is symptom-free. Her molecular genetic mutations analysis in the FAH gene detected a common intronel mutation, affecting splicing and of predicted severe effect, IVS6-1 g > t/IVS6-1 g > t with systemic name c.456-1 g > t/c.456-1 g > t (Prof. Magdalena Ugarte).

Collagen type IV nephropathy: genetic heterogeneity examinations in affected Hungarian families.

The Col4A3, Col4A4 and Col4A5 collagen type IV genes are found to be mutated in Col IV nephropathy. In males with a mutation in the Col4A5 gene (X-linked Alport syndrome: XL-AS), progressive renal disease always develops. Female carriers with a mutation in the Col4A5 gene can develop thin basement membrane nephropathy (TBMN). Males and females who carry 1 Col4A3 or Col4A4 mutation usually manifest TBMN with nonprogressive hematuria. In the event of 2 Col4A3 or Col4A4 gene mutations, the autosomal recessive AS will develop. We examined the cosegregation pattern of hematuria in 20 families. The renal biopsies led to diagnoses of AS in 7 families, and of TBMN in 6 families. In 7 others, the diagnosis of familial hematuria (FHU) was based on the clinical symptoms. Markers of the ColA3/Col4A4 and Col4A5 loci (Col4A3: CA11 and D2S401; Col4A4: HaeIII/RFLP; and Col4A5: DXS456, 2B6 and 2B20) were used to assess their linkage to the clinical symptoms and morphological alterations. Maximum likelihood and the FASTLINK version of the linkage program were applied to compute logarithm of the odds (LOD) scores. A linkage to the Col4A3/Col4A4 genes was identified in 5 families (FHU in 3, AS in 2 families, 25%, LOD score range: 0.20-3.51). The XL-AS pattern of inheritance seemed likely with Col4A5 in 9 families (45%, LOD: 0.43-4.20); we found 4 disease-causative mutations by high-resolution melting curve analysis (LC480) and sequencing in this group. In 2 FHU families, the linkage to chromosomes 2 and X was precluded. Knowledge of the genetic background of Col IV nephropathy is essential to avoid the misdiagnosis of FHU and early AS. The allele frequencies, heterozygosity content and polymorphism information content of the applied STR markers on unrelated Hungarian normal and affected chromosomes 2 and X were also calculated.

Outbreak of septicaemic cases caused by Acinetobacter ursingii in a neonatal intensive care unit.

Neonatal infections may be caused by various microorganisms, but as far as we are aware, Acinetobacter ursingii has not yet been reported in connection with nosocomial infections of premature infants. During 2 months, 3 premature babies were treated with nosocomial infection caused by A. ursingii at the same ward, and on the basis of molecular typing results the same strain was responsible for all of these cases. Traditional biochemical methods and automatic identification systems failed to identify this bacterium on the species level, and only 16S rDNA sequencing gave acceptable species identifications. The isolated strains proved to be susceptible to all of the tested antimicrobials, including ampicillin/sulbactam, doxycyclin, netilmicin, ciprofloxacin, piperacillin/tazobactam, ceftazidime, imipenem, meropenem, trimethoprim/sulfametoxazole, gentamicin, tobramycin, amikacin, and levofloxacin according to the CLSI standard. In spite of the environmental screening, the source of the infection could not be clarified. One of 3 neonates died, the others recovered and were discharged home after several months of hospitalization.

Microvascular reactivity in lean, overweight, and obese hypertensive adolescents.

UNLABELLED: The microvascular responses to endothelium-dependent vasodilators (e.g., acetylcholine), endothelium-independent vasodilators (e.g., sodium nitroprusside), and to local heating were studied (for the first time) in adolescents with essential hypertension, grouped according to their body mass index. The forearm microvascular reactivities of thirty-three hypertensive adolescents (ten lean, 13 overweight, and ten obese) and 19 healthy controls were assessed by means of laser Doppler flowmetry. Blood levels of enzymatic and nonenzymatic antioxidants and malondialdehyde were determined. The perfusion increments in response to acetylcholine iontophoresis were not significantly attenuated in the patient groups as compared with the controls. Sodium nitroprusside (SNP) iontophoresis resulted in significantly smaller perfusion increments in the lean and obese hypertensives than in the controls (both p < 0.05). Similar responses to local heating (44°C) performed after either acetylcholine or SNP iontophoresis were observed at the respective measurement sites. As compared with the controls, we found elevated ratios of the whole blood oxidized and reduced glutathione in all the patient groups (all p < 0.001), increased erythrocyte catalase activities in the overweight hypertensives (p < 0.05), and decreased ratios of the plasma alpha-tocopherol and triglycerides in the obese hypertensive group (p < 0.05). CONCLUSION: The endothelium-dependent microvascular reactivity was not significantly attenuated in the hypertensive adolescents in contrast with the impaired endothelium-independent vasorelaxation in the lean and obese hypertensives.

Primary microcephaly in Hungary: epidemiology and clinical features.

AIM: To describe the population-based epidemiological characteristics and clinical features of primary microcephaly in Hungary. METHODS: A retrospective survey of patients born with microcephaly in a region (Dél-Alföld - South Great Plain) in Hungary between July 1, 1992 and June 30, 2006 was performed. Patients with microcephaly and without any environmental or obstetric risk factors and/or dysmorphism (primary microcephaly) were included in the study. The birth prevalence of primary microcephaly per 10,000 live births was calculated. RESULTS: Ten patients (8 girls and 2 boys) were found with primary microcephaly among 185,486 live births, which corresponds to a birth prevalence of 0.54 per 10,000 live births (95% confidence interval: 0.20-0.87). Developmental delay and intellectual disability were the main clinical features. Dyskinesia was seen in one and epilepsy was diagnosed in two patients. The MRI revealed simplified gyral pattern in all patients. CONCLUSION: Primary microcephaly is a very rare brain malformation, although the birth prevalence found in this survey is slightly higher than the few figures published earlier. As more and more genes and mutations responsible for primary microcephaly are discovered, the ascertainment of these rare cases is mandatory to provide the parents with genetic counselling.

Blood pressure reference tables for Hungarian adolescents aged 11-16 years.

BACKGROUND/AIMS: Blood pressure (BP) during childhood is an established predictor of adult BP, which in turn predicts mortality in the event of cardiovascular disease. Reference data for systolic (SBP) and diastolic (DBP) BP are not available for Hungarian children (aged 11-14 years). The aim was to make up for this deficit. METHODS: Analyses were performed on 14,504 Hungarian children aged 11-16 years. All measurements were made with a validated, automated device. Criteria described by international guidelines were used. RESULTS: The 50th, 90th and 95th percentile BP values were defined by dividing the participating population into age-, gender- and height-specific subgroups. The SBP increased linearly with age to an apparent plateau at around the age of 15-16 years in both girls and boys, and there were similar increases in DBP and mean arterial pressure. Both the SBP and DBP revealed highly significant correlations in both genders with weight (SBP: r = 0.452, p < 0.01; DBP: r = 0.340, p < 0.01), height (SBP: r = 0.314, p < 0.01; DBP: r = 0.245, p < 0.01) and body mass index (SBP: r = 0.407, p < 0.01; DBP: r = 0.294, p < 0.01). CONCLUSION: The present study provides reference data on SBP and DBP, facilitating the diagnosis of essential hypertension in the 11- to 16-year age group.

Pontocerebellar hypoplasia type 1.

Pontocerebellar hypoplasias are heterogeneous disorders that share a reduction in the size of brainstem and cerebellum. We describe a patient with features of the rare combination of pontocerebellar hypoplasia and spinal motor neuron disease. Parental consanguinity, low Apgar scores, facial weakness, dysphagia, tongue fasciculations, stridor, generalized hypotonia, severe muscle weakness, areflexia, and congenital joint contractures were evident. Cranial magnetic resonance imaging revealed a small cerebellum and brainstem, and a muscle biopsy revealed neurogenic changes. These abnormalities suggested pontocerebellar hypoplasia type 1.

Increased heme oxygenase-1 expression in premature infants with respiratory distress syndrome.

Oxidative stress is known to play an important role in the pathogenesis of certain severe illnesses in preterm infants. The enzyme heme oxygenase-1 (HO-1) participates in cytoprotection against oxygen radical injury. We have previously described the role of HO-1 in physiologic adaptation by demonstrating the induction of HO-1 in healthy mature neonates and asymptomatic preterm infants. Our current aim was to investigate the HO-1 expression in preterm infants with respiratory distress syndrome (RDS). We collected venous blood samples from 28 preterm infants with RDS on the 1st, 3rd and 5th days after birth. The HO-1 mRNA expression was determined by means of a competitive reverse transcriptase PCR technique, and a quantitative blood count was performed on the residual blood sample. A significant increase in HO-1 expression was found in the preterm infants with RDS as compared with both the healthy mature and the asymptomatic premature groups. The elevation was approximately eight-fold. The platelet count displayed a significant negative association with the HO-1 expression, and in the RDS prematures with thrombocytopenia the HO-1 induction was significantly greater than in those with a normal platelet count. In conclusion, the RDS of prematures is accompanied by an elevated HO-1 expression during the first 5 days of life, consistent with the inflammatory and oxidative characteristics of the disease.

Congenital syringocystadenoma papilliferum.

We present a boy with a congenital, ulcerated nodule on the scalp. At birth, the lesion was considered to be the result of a traumatic injury, but a biopsy at the age of 6 months pointed to a diagnosis of syringocystadenoma papilliferum. We draw attention to the difficulty of identifying head lesions in young children from clinical signs alone.

X-linked myotubular myopathy: report of a case with novel mutation.

Myotubular myopathy is a well-defined entity within the centronuclear myopathy subgroup of congenital myopathies. The authors present a patient with the most severe X-linked recessive type (XLMTM). A baby boy presented at birth with severe hypotonia, weak spontaneous movements, arthrogryposis, and respiratory insufficiency. Muscle biopsy showed features of myotubular myopathy. The diagnosis was confirmed and further specified by genetic analysis, revealing a novel frameshift mutation (1314-1315insT) of the myotubularin-coding MTM1 gene. This case underlines the importance of interdisciplinary analysis of congenital muscle diseases, including histomorphological and genetic investigations.

[Myotubular myopathy. Case report and review of the literature]. / Myotubularis myopathia. Esetismertetés és irodalmi áttekintés.

The first Hungarian report of a case of myotubular myopathy is presented here, which is a recessive congenital disorder linked to X chromosome. The patient presented at birth with severe hypotonia, weak spontaneous movements, arthrogryposis and respiratory insufficiency. The biopsy showed the appearance of myotubular myopathy. The diagnosis was further confirmed by genetic analysis revealing a novel frameshift mutation (1314-1315insT) of the myotubularin-coding MTM1 gene.

[Neurovesical dysfunction in children with anorectal malformations]. / Hólyagbeidegzési zavarok anorectalis fejlodési rendellenességekben.

Chronic renal failure remain the most significant cause of morbidity and mortality in patients with anorectal malformation. The urological anomalies associated with anorectal malformations are not only anatomical, but also functional, the latter being related to congenital neurovesical dysfunction. The neurovesical dysfunction found in children with anorectal malformations results from a possible association with spinal dysraphism. The authors carried out urodynamic evaluation on 6 patients operated on for anorectal malformation by posterior sagittal anorectoplasty. 3 children had normal bladder function, but 3 had neurovesical dysfunction (1 unstable bladder, 2 neuropathic bladder). It is concluded that in patients with anorectal malformations urodynamic investigations should be performed as a routine investigation of the urinary tract. Consequently, patients with lower urinary tract dysfunction should receive prompt treatment, including clean intermittent catheterization, to prevent or reduce secondary urologic morbidity, especially loss of renal function.

Efficient Targeted Next Generation Sequencing-Based Workflow for Differential Diagnosis of Alport-Related Disorders.

Alport syndrome (AS) is an inherited type IV collagen nephropathies characterized by microscopic hematuria during early childhood, the development of proteinuria and progression to end-stage renal disease. Since choosing the right therapy, even before the onset of proteinuria, can delay the onset of end-stage renal failure and improve life expectancy, the earliest possible differential diagnosis is desired. Practically, this means the identification of mutation(s) in COL4A3-A4-A5 genes. We used an efficient, next generation sequencing based workflow for simultaneous analysis of all three COL4A genes in three individuals and fourteen families involved by AS or showing different level of Alport-related symptoms. We successfully identified mutations in all investigated cases, including 14 unpublished mutations in our Hungarian cohort. We present an easy to use unified clinical/diagnostic terminology and workflow not only for X-linked but for autosomal AS, but also for Alport-related diseases. In families where a diagnosis has been established by molecular genetic analysis, the renal biopsy may be rendered unnecessary.

[Collagen type IV nephropathy: from thin basement membrane nephropathy to Alport syndrome]. / IV-es típusú kollagén nephropathiák: a vékony bazális membrán nephropathiától az Alport-szindrómáig.

INTRODUCTION: Collagen type IV nephropathy includes the Goodpasture syndrome, thin basement membrane nephropathy and the Alport syndrome. Mutations in the coding Col(IV)A3/A4 and Col(IV)A5 genes are probable causes of the latter two. Thin basement membrane nephropathy is mostly familial and has an autosomal dominant inheritance, at least 40% of the families have hematuria that co-segregates with the Col(IV)A3 and/or Col(IV)A4 loci. 85% of Alport syndrome cases are transmitted as an X-linked semidominant form due to Col(IV)A5 mutations. About 14% of Alport syndrome cases exhibit autosomal recessive, and 1% autosomal dominant inheritance, both caused by mutations in the Col(IV)A3 or Col(IV)A4 genes in boys and in girls. AIM: The co-segregation pattern of hematuria was examined in two families with thin basement membrane nephropathy and one family with the Alport syndrome, using short tandem repeat markers, spanning the Col(IV)A3/A4 and Col(IV)A5 loci to assess their linkage to the clinical symptoms and morphological alterations in the renal biopsy specimens. METHODS: Markers: Col(IV)A3: CAll and D2S401; Col(IV)A4: HaeIII/RFLP; and Col(IV)A5: DXS456, 2B6 and 2B20. RESULTS: The hematuria displayed autosomal dominant inheritance and co-segregated with Col(IV)A3 markers in one of the thin basement membrane nephropathy families. In the second, the hematuria did not segregate with the Col(IV)A3/A4 or Col(IV)A5 loci, suggesting the possibility of another genetic locus for the disease. The Alport syndrome exhibited autosomal recessive inheritance and did not link to Col(IV)A5 markers, and the Col(IV)A3/A4 markers were informative only in part. CONCLUSION: Knowledge of the inheritance and genetic background of collagen type IV nephropathy will be very important in the diagnostics and genetic counseling in the future.

Methotrexate inhibits the glyoxalase system in vivo in children with acute lymphoid leukaemia.

The inhibition of glyoxalase I leads to antitumour activity through the accumulation of methylglyoxal. Our earlier observations suggested that methotrexate (MTX) may affect the glyoxalase system. This prompted a serial study of the drug on this metabolic pathway. Ten children with acute lymphoid leukaemia (ALL), admitted to our department between January 2002 and July 2003, were enrolled. Plasma D-lactate was assayed before, 24 and 72 h after the start of four consecutive MTX infusions (5 g/m(2)/24 h) in each patient. Inhibition of glyoxalase I was tested in vitro, using human erythrocyte lysates and yeast enzyme. The elevated initial plasma D-lactate levels (P<0.02) fell significantly (P<0.001) in response to 24 h MTX infusions. In vitro, MTX, folic and folinic acids inhibited the activity of glyoxalase I. Thus, MTX seems to affect the alpha-oxoaldehyde metabolism in vivo, as a likely consequence of glyoxalase I inhibition. This action probably contributes to the anticancer activity and toxicity of the drug.

Oxidative stress in juvenile essential hypertension.

OBJECTIVE: Oxidative stress, an antioxidant/pro-oxidant imbalance, in patients with juvenile essential hypertension was measured via several biochemical parameters. As the blood pressure is associated with the body mass index (BMI), results were compared with those on BMI-matched controls. DESIGN AND SETTING: A prospective observational study at a university teaching hospital. PATIENTS: Children and adolescents with essential hypertension (mean standard deviation: age 14.4 +/- 3.1 years, BMI 25.0 +/- 6.9 kg/m(2), n = 52) before any treatment, and controls with a similar BMI distribution (age 14.3 +/- 4.3 years, BMI 24.4 +/- 6.6 kg/m(2), n = 48). METHODS: Measurements were made of the plasma levels of (1) nitrites + nitrates, an indirect measure of available nitric oxide; (2) lipid peroxidation end-products, as malondialdehydes and free thiols; and (3) the redox status of the red blood cell glutathione, as a new oxidative stress parameter. RESULTS: There were decreased plasma levels of nitrates and increased levels of lipid peroxidation end-products in the hypertensive patients, resulting in a consistent increase in the plasma lipid peroxidation/nitric oxide ratio as compared with the controls with the same BMI (P <0.01). This ratio additionally correlated directly with both the systolic and diastolic blood pressures for the overall patient population (P <0.001). A significant glutathione depletion in the red blood cells resulted in an elevated ratio of oxidized/reduced forms with a reduced antioxidant protective capacity in the hypertensive patients versus the BMI-matched controls (P <0.001). CONCLUSIONS: The presence of systemic oxidative stress was proven in hypertensive children and adolescents, irrespective of their BMI.