Andreas Fretzayas

Evaluation of a rapid antigen detection test in the diagnosis of streptococcal pharyngitis in children and its impact on antibiotic prescription

OBJECTIVES To study the performance of the Becton-Dickinson Link 2 Strep A Rapid Test, a rapid antigen detection test (RADT) for diagnosing streptococcal pharyngitis in children presenting to private offices and to the Pediatric Outpatient Clinic of a university hospital, in relation to clinical criteria (fever, tender anterior cervical lymph nodes, tonsillar exudate and absence of cough), and its impact on antibiotic prescription. METHODS Children were enrolled in Group A (enrolment by private-practice paediatricians; diagnosis by clinical picture only), Group B (enrolment by private-practice paediatricians; diagnosis by RADT and culture) or Group C (enrolment by hospital-affiliated paediatricians in the Pediatric Outpatient Clinic; diagnosis by RADT and culture). RESULTS During a 2 year period, 820 children were enrolled [369 (45%) in Group A, 270 (33%) in Group B and 181 (22%) in Group C]. Streptococcal pharyngitis was diagnosed by RADT and culture in 146 (32.4%) of the 451 tested children. The sensitivity, specificity and positive and negative predictive values of the RADT were 83.1%, 93.3%, 82.4% and 93.6%, respectively. A stepwise increase in the sensitivity of the RADT was noted among children with one, two, three or four clinical criteria (60.9% to 95.8%). Paediatricians without access to laboratory tests were more likely to prescribe antibiotics compared with paediatricians with access to tests (72.2% versus 28.2%, P < 0.001). Private-practice paediatricians prescribed antibiotics more frequently compared with hospital-affiliated paediatricians (55.7% versus 19.9%, P < 0.001). CONCLUSIONS Our findings support screening of all children with pharyngitis for Centor criteria and subsequently performing an RADT to guide decision for antibiotic administration. Such a strategy has an important impact on limiting throat culture testing and is associated with reduced antibiotic prescription.

A Novel Monocarboxylate Transporter 8 Gene Mutation as a Cause of Severe Neonatal Hypotonia and Developmental Delay

Monocarboxylate transporter 8 acts as a specific cell membrane transporter for thyroxine and especially triiodothyronine into target cells. It is expressed in brain neurons and in many other tissues. The monocarboxylate transporter 8 gene resides on chromosome Xq13.2. An 11-month-old male infant was referred because of severe hypotonia from early life and global developmental delay. Thyroid-function tests showed normal thyrotropin levels and the characteristic for the disorder, including high serum triiodothyronine and low thyroxine concentrations. Molecular analysis of the monocarboxylate transporter 8 gene showed that the patient was hemizygous for a novel missense mutation P537L. This case highlights the importance of determining thyroid hormone levels, especially triiodothyronine, in infants with severe neonatal hypotonia.

Effects of anticonvulsant therapy on vitamin D status in children : Prospective monitoring study

Reports of hypovitaminosis D associated with anticonvulsant drugs in pediatric patients are conflicting. The effects of carbamazepine or sodium valproate on vitamin D status were evaluated prospectively in 51 ambulatory epileptic children who were followed during the first year of the study and in 25 and 6 children during the second and third year, respectively. Serum 25-hydroxyvitamin D, parathyroid hormone, calcium, and phosphorus levels were determined before and every 3 months during anticonvulsant therapy. Our subjects were grouped into four classes (0, 1, 2, and 3 consisted of the patients before and during the first, second, and third years of the treatment, respectively). The control group consisted of 80 healthy children. Comparisons between controls and patients of class 0 for the means for each season of all variables showed no significant differences. A decreasing trend in serum 25-hydroxyvitamin D (P < .03) and an increasing trend in serum parathyroid hormone (P < .04) levels were noticed in all seasons from class 0 to class 3. Twenty-five patients (49%) acquired hypovitaminosis D during the study period. The effects of seasonality on serum 25-hydroxyvitamin D, parathyroid hormone, and calcium were noticed in our patients grouped in classes 0, 2 and 3, as well as in controls. Evidence is provided that carbamazepine or sodium valproate can cause hypovitaminosis D in children. (J Child Neurol 2006; 21:205—209; DOI 10.2310/7010.2006.00050)

Age at menarche in contemporary Greek girls: evidence for levelling-off of the secular trend

Aim: To examine the secular trend of menarcheal age in Greek girls during the last decade.

Constitutional Advancement of Growth, a.k.a. Early Growth Acceleration, Predicts Early Puberty and Childhood Obesity

CONTEXT Constitutional advancement of growth (CAG), a.k.a. early growth acceleration, refers to a growth pattern that is characterized by growth acceleration soon after birth, reaching a zenith centile in the first 2 to 4 yr of life and followed by normalization of the growth rate until the onset of puberty, which is usually early. CAG is the mirror image of the growth pattern of constitutional delay of growth and puberty, which is characterized by growth deceleration in the first years of life that is followed by normalization of the growth rate and late onset of puberty. For a child to be considered as presenting CAG, other conditions that lead to early growth acceleration, like genetic tall stature, infant overfeeding, and intrauterine growth restraint, have to be excluded. EVIDENCE ACQUISITION This review was based on our own data supplemented by relevant articles identified by a PubMed search. EVIDENCE SYNTHESIS Girls with idiopathic precocious puberty almost invariably present the growth pattern of CAG. Moreover, the growth pattern of growth acceleration in the first years of life, i.e. CAG, is also present in children that become obese later in childhood; thus, it may be considered a risk factor for childhood obesity. CONCLUSIONS Given the strong association between childhood obesity and early puberty, especially in girls, infants that present the pattern of CAG have to be monitored for the development of early puberty or/and obesity.

Working mothers breastfeed babies more than housewives.

Aim: To examine the prevalence and determinants of breastfeeding and to identify perinatal, sociodemographic, psychosocial and environmental factors associated with maternal infant feeding intention.

Low TSH levels are not associated with osteoporosis in childhood

INTRODUCTION A recent study on TSH receptor (TSHR) null mice suggested that skeletal loss occurring in hyperthyroidism is caused by the low TSH rather than high thyroid hormone levels. The aim of this study was to examine whether low TSH results in osteoporosis in the human. SUBJECTS AND METHODS We determined bone mineral density (BMD) and markers of bone metabolism in two male siblings aged 9.8 and 6.8 years with isolated TSH deficiency, due to a mutation of the TSH beta-subunit gene. BMD was measured in the lumbar spine (L1-L4) by dual-energy X-ray absorptiometry. Laboratory investigation included the determination of serum calcium, phosphate, 25-hydroxy-vitamin D, parathyroid hormone concentrations, and urine calcium (Ca)/creatinine (Cr) ratio. Osteoblast activity was measured by serum bone alkaline phosphatase and osteocalcin levels, and osteoclast activity by urine cross-linked amino-terminal, carboxy-terminal telopeptides of type I collagen and deoxypyridinoline concentrations. RESULTS BMD of both patients was within the normal range for age and sex; z-scores were -0.55 and -0.23 for patients 1 and 2 respectively. Serum calcium, phosphate, urine Ca/Cr ratio, and specific markers of bone metabolism were also within normal range. CONCLUSION In childhood, chronic extremely low TSH levels, in the face of normal thyroid hormone levels, are not related to bone loss.

Timing of Pubertal Onset in Girls: Evidence for Non-Gaussian Distribution

CONTEXT The timing of the onset of puberty is considered to approximate a normal distribution. However, because many more girls present with early than late puberty, we hypothesized that the distribution of the timing of the onset of puberty in girls might have changed. OBJECTIVE/SUBJECTS: The objective of the study was to examine the distribution of the timing of the onset of puberty in normal Greek girls. DESIGN Onset of puberty, i.e. breast development (B2), was studied longitudinally in 311 prepubertal schoolgirls aged 6.4-8.2 yr until the onset of puberty. We also studied cross-sectionally 126 girls, 6-14 yr old. SETTING Clinical examinations took place in the school setting. RESULTS In the longitudinal study, median of the distribution of age at B2 was 10.0 yr (with the 25th and 75th centiles being 9.2 and 10.6 yr, respectively). Skewness was -0.45 (P=0.001), suggesting a negatively skewed distribution. In the cross-sectional study, 126 subjects were found at B2. The median of the age distribution at B2 was 10.1 yr (with the 25th and 75th centiles being 9.7 and 11.2 years, respectively). Skewness was -0.44 (P=0.03), suggesting a negatively skewed distribution. CONCLUSIONS A non-Gaussian distribution of the age at the onset of puberty in girls was documented. The currently used cutoff ages for precocious and delayed puberty may not be applicable to modern children; therefore, up-to-date studies on pubertal maturation are much needed.

Pubertal Maturation of Contemporary Greek Boys: No Evidence of a Secular Trend

PURPOSE To examine pubertal status of contemporary Greek boys and compare the data with those of a previous study we performed in the year 1996. METHODS We performed a cross-sectional study of 932 healthy boys, aged from 8.05 to 16.05 years. Development of the genitalia (G) and pubic hair was assessed by the method of Tanner and testicular volume (TV) was determined with a Prader orchidometer. Genitalia stage 2 (G2) was assessed by probit analysis. RESULTS Median (95% confidence interval [CI]) age at G2, defined as TV 4 mL, was 11.3 (10.9-11.6) years, almost the same age as in our study performed in 1996, which was 11.4 (10.7-11.7) years (p = .21). When G2 was defined as change in scrotum texture and TV2 mL, median (95% CI) age at onset of puberty was 10.9 (10.5-11.3) years, again similar to the study performed in 1996 which was 11.0 (10.7-11.4) (p = .32). Median (95% CI) age of pubic hair development was 11.2 (10.8-11.6) years versus 11.5 (11.1-12.0) years in 1996, p = .015. CONCLUSIONS Our data provide no evidence of a secular trend for gonadarche in Greek boys, although such a trend was evident for pubarche.

Calcium and Vitamin D Metabolism in Hypocalcemic Vitamin D-Resistant Rickets Carriers

Background/Aims: Hypocalcemic vitamin D-resistant rickets (HVDRR) is a rare monogenic autosomal recessive disorder associated with mutations in the gene of the vitamin D receptor (VDR), the mediator of 1,25(OH)2D3 action. Although many investigations have discussed the clinical manifestations and molecular etiology of this disease, only a few have investigated the biochemical and hormonal status of heterozygous HVDRR. The aim of the current work was to investigate the profile of selected biochemical and hormonal parameters related to the vitamin D endocrine system in a large number of HVDRR heterozygotes. Methods: 67 relatives of 2 HVDRR patients, all members of an extended Greek kindred of five generations with a common ancestor, were included in the study. Direct sequencing was used to identify VDR gene mutations. Serum Ca, P, 25(OH)D, iPTH, and 1,25(OH)2D levels were determined in all members of the kindred. Results: DNA analysis of the participants led to the design of two study groups: the HVDRR carriers (24) and the control subjects (43). Our results showed elevated circulating serum levels of 1,25(OH)2D3 and lower levels of PTH than their age- and sex-matched controls. No hypocalcemia or hypophosphatemia were detected in HVDRR carriers. Conclusions: Our findings suggest that HVDRR carriers may have compensatory elevated serum levels of 1,25(OH)2D3 through which they restrain PTH secretion. The study of HVDRR carriers could be a useful tool for the investigation of the vitamin D endocrine system.