[Seasonal variations in 25-hydroxy vitamin D3, parathormone and alkaline phosphatase in school-aged children]. / Variación estacional de 25-hidroxi-vitamina D3, hormona paratiroidea y fosfatasa alcalina en niños escolares.

INTRODUCTION: The main role of Vitamin D is to regulate calcium metabolism, whose main source is vitamin D3 ob tained mostly from the action of ultraviolet (UV) light on the skin. OBJECTIVE: To evaluate the seaso nal differences in the concentrations of 25-hydroxy-vitamin D3 (25OHVitD3), parathyroid hormone (PTH), alkaline phosphatase (ALP), and calcium in school-age children. SUBJECTS AND METHOD: The concentrations of 25OHVitD3, PTH, ALP, and calcium were measured in children from Santiago, Chile (latitude -33.4372), aged 5 to 8 years, without Vitamin D supplementation, in different seasons of the year. VitD status was defined as sufficient with concentrations of 25OHVitD3 >20 ng/mL (50 nmol/L), insufficient 12-20 ng/mL (30-50 nmol/L) and deficient <12 ng/mL (30 nmol/L) based on the recommendations of the expert group of the "Global Consensus for the Prevention and Mana gement of Nutritional Rickets". RESULTS: 133 children participated (89 preterms under or equal to 32 weeks), 41 during summer, 28 in fall, 35 in winter, and 29 in spring. The difference of means between summer and winter was 9.6 ng/mL for 25OHVitD3 (p <0.0001), -11.1 pg/mL for PTH (p <0.0001), and -47.5 IU/mL for ALP (p= 0.01). There were no differences in calcium concentrations. In sum mer, 97.6% of the subjects were classified with sufficiency status (> 20 ng/mL), which decreased significantly in winter to 54.3% (p <0.0001). CONCLUSIONS: In winter, 25OHVitD3 concentrations decreased in approximately half of the children, which was associated with an increase in PTH and ALP, and normal calcium concentrations. According to our results, children may need VitD supple mentation during fall and winter.

[Diabetes mellitus caused by a mutation of glucokinase gene. Report of an affected family]. / Diabetes mellitus por mutación en el gen de glucokinasa. Caso clínico.

Maturity-Onset Diabetes of the Young (MODY) refers to a heterogeneous group of monogenic diabetes. Unlike other types of MODY characterized by genetic defects in transcription factors, MODY 2 is triggered by metabolic alterations caused by mutations of glucokinase (GCK), the first enzyme of the glycolytic pathway. We report a three-generation Chilean family with multiple cases affected with this disease. The index case is a patient who presented severe neonatal hyperglycemia (831 mg/dl, without ketosis) requiring continuous infusion of insulin, which was suspended after 48 hours with normalization of blood glucose. Subsequently, continuous glucose monitoring at 4 months of age revealed 47% of tissue glucose levels above 140 mg/dl, with fasting glucose levels between 120 and 166 mg/dl. The genetic analysis revealed a previously reported mutation in heterozygous state of the GCK gene (c.148C>T; p.His50Tyr). This mutation was also identified in more than one affected relative in the last two generations, with a transmission pattern suggestive of dominant inheritance. GCK gene sequencing led to a correct molecular diagnosis of MODY 2 while bioinformatic analysis indicated the possible molecular causes of the enzyme dysfunction. The knowledge of the molecular diagnosis allowed an adequate medical treatment for this disease.

[Persistent elevation of aspartate aminotransferase (AST) due to the presence of macro-AST: Report of one case]. / Aumento aislado y sostenido de aspartato aminotransferasa por presencia de macroenzimas: Caso clínico.

We report an asymptomatic 23-year-old woman with an isolated and persistent increase in serum levels of aspartate aminotransferase (AST). An extensive work up including laboratory and image testing revealed no abnormalities thus suggesting the presence of macro-AST. A polyethylene glycol (PEG) precipitation assay was performed and confirmed the presence of macro-AST.

[Human papillomavirus testing in cervical cancer screening at a public health service of Santiago, Chile]. / Examen de detección de virus papiloma humano en el tamizaje de cáncer cervicouterino en un Servicio de Salud de Santiago, Chile.

BACKGROUND: Molecular techniques for human papillomavirus (HPV) detection have a good performance as screening tests and could be included in cervical cancer early detection programs. We conducted a population-based trial comparing HPV detection and Papanicolaou as primary screening tests, in a public health service in Santiago, Chile. AIM: To describe the experience of implementing this new molecular test and present the main results of the study. MATERIAL AND METHODS: Women aged 25 to 64 enrolled in three public health centers were invited to participate. In all women, samples were collected for Papanicolaou and HPV DNA testing, and naked-eye visual inspection of the cervix with acetic acid was performed. Women with any positive screening test were referred to the local area hospital for diagnostic confirmation with colposcopy and biopsy of suspicious lesions. RESULTS: Screening results were obtained for 8265 women, of whom 931 (11.3%) were positive to any test. The prevalence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was 1.1%; nine women had invasive cervical cancer. Sensitivities for the detection of CIN2+ were 22.1% (95% confidence interval (CI) 16.4-29.2) for Papanicolaou and 92.7% (95% CI 84.4-96.8) for HPV testing; specificities were 98.9% (95% CI 98.7-99.0) and 92.0% (95% CI 91.4-92.6) respectively. CONCLUSION: This experience showed that the implementation of a molecular test for cervical cancer screening is not a major challenge in Chile: it was well accepted by both the health team and the participants, and it may improve the effectiveness of the screening program.

[Effect of VKORC1 and CYP2C9 variants on dosage of oral anticoagulants in Chilean individuals]. / Efecto de las variantes de VKORC1 y CYP2C9 sobre la dosis de anticoagulantes orales en individuos chilenos.

BACKGROUND: The dose of oral anticoagulants (OAC) shows great variability among patients. Pharmacogenetic studies have shown that common variants in genes CYP2C9 (*2 and *3) and VKORC1 (-1639G>A) are associated with lower requirements of OAC. AIM: To study the association between average maintenance doses of oral anticoagulant therapy required to maintain a stable INR and CYP2C9 and VKORC1 gene variants in Chilean adults. MATERIAL AND METHODS: Prospective study of patients on anticoagulant treatment and with a stable international normalized ratio (INR) for prothrombin time for at least three months. Patients were classified as having high or low acenocoumarol or warfarin requirements. Peripheral blood DNA genotyping was performed by polymerase chain reaction and restriction fragment polymorphism or sequencing and electrophoresis. RESULTS: The study included 185 patients, 125 on acenocoumarol and 60 on warfarin. Patients with VKORC1-1639A allele were more likely to require lower doses of both drugs than patients with the G allele (Odds ratio [OR] for acenocoumarol 9.06, and OR for warfarin = 18.7). There was no association between CYP2C9*2 and*3 and acenocoumarol or warfarin requirements. CONCLUSIONS: There is an association between VKORC1-1639A variant and anticoagulant doses.

Screening trial of human papillomavirus for early detection of cervical cancer in Santiago, Chile.

Cervical cancer mortality in Chile is four times higher than in developed countries. We compared the accuracy of human papillomavirus (HPV) DNA testing and conventional Papanicolaou (Pap) testing to detect prevalent precancerous and cancerous lesions in the routine clinical practice of the public health system. Women aged 25 years and older residing in the area covered by three primary care centers of Santiago, Chile, were invited to participate. Eligible women received both HPV DNA (Hybrid Capture 2) and Pap testing. Women positive by either test (Pap: ASCUS+, HC2: RLU/CO ≥ 1.0) underwent colposcopy and biopsy, as did a sample of double-negative women with an abnormal cervix at visual inspection or with risk factors for cervical lesions. Crude and verification bias-corrected sensitivities and specificities were estimated. In total, 8,265 women (98.8% of eligible) had complete screening results. Of these, 10.7% were HPV positive, 1.7% were Pap positive and 1.1% were positive by both tests. In all, 931 (11.3%) women were screen-positive, of whom 94.3% attended colposcopy. Additionally, 295 control women were invited for colposcopy, of whom 78% attended. In all, 42 CIN2, 45 CIN3 and 9 cancers were identified. Verification bias-corrected sensitivity for CIN2+ (95% confidence interval) was 92.7% (84.4-96.8) for HPV and 22.1% (16.4-29.2) for Pap; corresponding specificities were 92.0% (91.4-92.6) and 98.9% (98.7-99.0). In conclusion, in routine clinical practice in a developing country, HPV testing was four times more sensitive for CIN2+ than Pap testing, identifying three times more CIN2+ lesions; HPV testing was easily implemented in our established cervical cancer prevention program.

Extremely and very preterm children who were born appropriate for gestational age show no differences in cortisol concentrations or diurnal rhythms compared to full-term children.

OBJECTIVES: The objective of this study was to compare the diurnal variations in cortisol and cortisone concentrations in serum and saliva among extremely preterm (EPT), very preterm (VPT), and full-term (FT) children, all born appropriate for gestational age (AGA). METHODS: EPT, VPT, and FT children, all born AGA, were recruited from two healthcare centers. Cortisol and cortisone concentrations in serum and saliva were measured by liquid chromatography-mass spectrometry (LC‒MS). Statistical analysis was performed using nonparametric tests. RESULTS: A total of 101 children (5.0-8.9 years old) were included in this study: EPT=18, VPT=43 and FT=40. All groups had similar distributions in terms of age, birth weight standard deviation score (SDS) and BMI (SDS), showing no differences in serum ACTH, cortisol, or cortisone levels. Additionally, salivary cortisol and cortisone concentrations decreased significantly throughout the day (p-values<0.0001). Salivary cortisol concentrations were below the limit of detection (0.55 nmol/L) before dinner and before bedtime in approximately one-third and two-thirds of all children, respectively. Salivary cortisone was detectable in all but one sample. CONCLUSIONS: The diurnal cortisol rhythm was preserved in all preterm children, regardless of their gestational age, and no differences in cortisol concentrations among the groups were found. This may have significant implications for the clinical management and follow-up of preterm individuals.

Facial Dysmorphic Features in a Patient With Nonketotic Hypoglycemia and a Pathogenic Variant in the AKT2 Gene.

Background/Objective: AKT2 is a serine/threonine kinase that plays a key role in regulating insulin signaling. The phenotype related to the gain-of-function alteration in the AKT2 gene (c.49G>A, p.Glu17Lys) has been described in 5 patients with clinical findings that mimic hyperinsulinemic hypoglycemia but with undetectable levels of insulin and C-peptide. One of the reports highlights the facial dysmorphic features. We report the case of a new patient with the same activating AKT2 alteration leading to autonomous activation of the insulin signaling pathway and dysmorphic features. Moreover, to our knowledge, this is the first report using waxy maize heat-modified starch (WMHMS) in this condition. Case Report: A previously healthy child was evaluated at 6 months of age for episodes of hypoglycemia. The laboratory test results for the critical samples showed hypoketotic hypoglycemia (glucose level, 2.16 mmol/L [38 mg/dL]) with undetectable levels of insulin (<0.2 mU/L) and C-peptide (<0.033 nmol/L [reference range, 0.37-1.47 nmol/L]). Physical examination revealed hypertelorism, prominent proptosis of the eyes, a flat nasal bridge, delayed psychomotor development, and postnatal symmetrical overgrowth. The genetic study of AKT2 showed a pathogenic variant (c.49G>A, p.Glu17Lys). To achieve euglycemia, a diet of regular uncooked cornstarch (UCCS) carbohydrate was started. Subsequently, waxy maize heat-modified starch (WMHMS; Glycosade Vitaflo) was used to increase the fasting period to 4 hours. However, we did not find any advantages in comparison with UCCS. Discussion: The range of phenotypes of this gain-of-function alteration in AKT2 may be broad, including dysmorphic features, although the patients harbor the same pathogenic variant. Conclusion: Regarding the treatment, we observed a similar response with WMHMS compared with UCCS, with no adverse effects.

Insulin resistance parameters in children born very preterm and adequate for gestational age.

BACKGROUND: Preterm neonates are at risk for metabolic syndrome later in life. Whether prematurity constitutes an independent risk factor for the development of cardiovascular disease and metabolic syndrome remains controversial. OBJECTIVE: To compare anthropometric measures, cardiometabolic risk factors and insulin resistance variables between children who were born very preterm (VPT, <32 gestational weeks) and at term (Term, >37 gestational weeks) and adequate for gestational age (AGA). METHODS: We designed a cross-sectional cohort study, recruiting 120 children (5.0-8.5 years old) from the preterm clinic at Red de Salud UC-Christus and Complejo Asistencial Dr. Sótero del Río, and term children from the community. We excluded children born small for gestational age, based on INTERGROWTH21. Anthropometrics data were classified using WHO reference standards. The homeostasis model assessment insulin resistance (HOMA-IR) index, quantitative insulin sensitivity check index (QUICKI), triglyceride-to-HDL-C ratio (TG/HDL-C) and Pediatric Score Index for Metabolic Syndrome (PsiMS) were calculated. RESULTS: VPT children born AGA had lower HDL cholesterol levels (p = .019) and a higher PsiMS score than those born at term (p = .043). We observed a higher percentage of children with HDL cholesterol ≤40 mg/dl (13.0% vs. 2.3%, p = .026) and BP ≥90th percentile among the VPT children than among the Term children (26.0% vs. 11.6%, p = .031). CONCLUSIONS: At school age, blood pressure was higher, and HDL-C was lower among VPT children born AGA, suggesting a potential metabolic risk; therefore, it is essential to follow this group throughout their lives.

Endemic scrub typhus-like illness, Chile.

We report a case of scrub typhus in a 54-year-old man who was bitten by several terrestrial leeches during a trip to Chiloé Island in southern Chile in 2006. A molecular sample, identified as related to Orientia tsutsugamushi based on the sequence of the16S rRNA gene, was obtained from a biopsy specimen of the eschar on the patient's leg. Serologic analysis showed immunoglobulin G conversion against O. tsutsugamushi whole cell antigen. This case and its associated molecular analyses suggest that an Orientia-like agent is present in the Western Hemisphere that can produce scrub typhus-like illness. The molecular analysis suggests that the infectious agent is closely related, although not identical, to members of the Orientia sp. from Asia.

[Basic concepts about paternity testing]. / Conceptos básicos sobre el estudio de paternidad.

Nowadays, the analysis of genetic markers is a very important and validated tool for the identification of individuals, and for paternity testing. To do so, highly variable regions of the human genome are analyzed, making it possible to obtain the genetic profile of an individual, and to distinguish between different individuals. The methodology used is basically the same all over the world, consisting in the analysis of 13 to 15 markers. To assign biological paternity the child must have inherited the characteristics from the alleged father in each of the genetic markers analyzed. This analysis achieves a certainty higher than with any other test, which is expressed as the probability of paternity. This probability has to be at least 99.9%, but greater probabilities are usually obtained, especially if the mother is included in the analysis. If the characteristics of two or more genetic markers from the alleged father are absent in the child, biological paternity is excluded.

[Introns 1 and 22 inversions and F8 gene sequencing for molecular diagnosis of hemophilia A in Chile]. / Análisis de las inversiones del intrón 1 y 22 y secuenciación del gen F8 para el diagnóstico genético-molecular de hemofilia A en Chile.

BACKGROUND: Hemophilia A is an inherited disorder caused by alterations in factor VIII gene (F8) located on the X-chromosome, the intron 22 inversion being the most common mutation. The rest are predominantly point mutations distributed along this large gene of 26 exons. AIM: To implement a molecular diagnostic test to detect mutations in the F8 gene in Chilean patients with Hemophilia A. MATERIAL AND METHODS: To validate the testing methods, we analyzed samples with intron 22 and intron 1 inversion, and with point mutations previously studied, as well as one subject without Hemophilia. We also studied unrelated Chilean patients with Hemophilia A and their female relatives for carrier testing. Intron 22 and intron 1 inversions were studied by long distance polymerase chain reaction (PCR) and point mutations by sequencing the coding and promoter regions of the F8 gene. RESULTS: The results obtained in all samples used for validation were concordant with those obtained previously. In the Chilean patients, the intron 22 inversion and point mutations previously described were observed. In 6 out of 9 patients with mild Hemophilia A we found the same mutation (Arg2159Cys) in exon 23, which has been described as prevalent in mild Hemophilia A. CONCLUSIONS: The analysis of intron 22 and intron 1 inversions, as well as of point mutations in the F8 gene will help us to confirm the diagnosis in patients with severe, moderate and mild Hemophilia A, and also it will allow us to perform carrier testing and to provide better genetic counseling.

[Laboratory diagnosis of Treponema pallidum infection in patients with early syphilis and neurosyphilis through a PCR-based test]. / Diagnóstico de la infección por Treponema pallidum en pacientes con sífilis temprana y neurosífilis mediante reacción de la polimerasa en cadena.

Syphilis is a sexually transmitted disease caused by Treponema pallidum. The diagnosis is based mainly in clinical presentation and non-specific assays. PCR-based diagnosis has been suggested as an attractive alternative method. The aim of this study was the validation of a PCR-based test for the diagnosis of early syphilis (ES) and neurosyphilis (NS). Clinical samples of mucocutaneous lesions and cerebrospinal fluid (CSF) specimens from patients previously diagnosed for ES and NS respectively using an enlarged gold standard, were tested by PCR. The reaction was done using primers targeting the tpN47 gene. Twenty out of 21 mucocutaneous samples from patients diagnosed with ES were positive by PCR, with a clinical sensitivity of 95%. Four out of 8 CSF samples from patients previously diagnosed with NS were positive by PCR, with a clinical sensitivity of 50%. The clinical specificity for both ES and NS was 100%. The PCR sensitivity and specificity for mucocutaneous samples allowed us to implement this assay in our laboratory for routine diagnosis. Although the sensitivity of the PCR in CSF was low, it may be useful to support clinical diagnosis.

Quality of Life in Chilean Transgender Children and Adolescents.

INTRODUCTION: Transgender (TG) children and adolescents experience problems in school as well as with family and social relationships that can adversely affect their physical and psychosocial health and impair their quality of life (QoL). This study aimed to assess health-related quality of life (HRQoL) in TG children. METHODS: We performed a cross-sectional study comparing HRQoL in gender non-conforming (Trans) and gender-conforming (CIS) children and adolescents using the Spanish version of KIDSCREEN-52 in 120 Chilean Trans and CIS children (aged 8-18 years) and their parents. All scores were standardized according to the KIDSCREEN manual. RESULTS: Among the 100 questionnaires answered, 38 corresponded to children and adolescents aged 8.4-18 years. Twenty-one of them were TG (71% trans males) and 17 were CIS (76% females). Sixty-two parents answered the questionnaires: 33 from families of TG children (PTrans) and 29 from families of CIS children (PCis). Trans children had lower HRQoL scores in all domains than CIS children. The lowest-scoring domains for TG children were "Moods and Emotions," "Psychological Well-Being" and "Social Acceptance," and the highest-scoring domain was "School Environment." The PTrans group had significantly higher scores than the Trans group for 3 of the 10 domains: "Psychological Well-Being," "Moods and Emotions," and "Parent Relations and Home Life." CONCLUSION: Our results revealed that TG children and adolescents have lower QoL than their CIS counterparts, especially regarding items related to mental health. Furthermore, their parents may underestimate their well-being, confirming the vulnerability of the TG population. This finding underlies the need to perform early assessments of QoL for early detection and intervention in aspects that could deteriorate their quality of life.

Different Clinical Manifestations Related to Subvirilization in Three XY Patients With the Same Pathogenic Variant of Steroidogenic Factor 1.

OBJECTIVE: During the prenatal period, steroidogenic factor 1 is required for the development of the adrenal glands and for gonadal determination and differentiation, and after birth, it regulates gonadal progenitor cell formation and their survival. Here, we describe the clinical phenotype of three 46,XY patients (2 brothers and an unrelated subject) with disorder of sex development due to the same genetic variant. METHODS: All patients underwent hormonal and pelvic ultrasound studies. Sequence analysis and deletion/duplication testing of a panel encompassing 8 genes (AR, DHH, MAP3K1, NROB1, SRD5A2, SRY, WT1, and nuclear receptor subfamily 5, group A, member 1 [NR5A1]) were performed in the index cases. All family members were tested for the presence of the NR5A1 variant. RESULTS: A variant previously described as likely pathogenic in NR5A1 (c.251G>A, p.Arg84His) that segregated in 1 family with different degrees of under-virilization was found. The family 1 index case (IV2) and his brother (IV3) had an external masculinization scale score of 5/12, but only the index case had Müllerian remnants; however, the family 2 patient had a milder score of 9/12. The older female relatives of family 1 who harbor this variant experienced premature menopause. CONCLUSION: To our knowledge, this is the first report where the c.251G>A (p.Arg84His) variant is associated with the presence of Müllerian remnants in 46,XY subjects and primary ovarian insufficiency in 46,XX individuals. The segregation of this variant with clinical manifestations provides further evidence for considering it as pathogenic.

Perinatal antecedents of sleep disturbances in schoolchildren.

STUDY OBJECTIVES: Prematurity has been associated with an increased risk for sleep apnea. However, sleep disturbances in children born preterm have not been extensively investigated. Considering that determinants of sleep may originate early in life, the potential impact of prematurity on sleep disturbances later in life could be important. To establish the role of prematurity on sleep disturbances in a cohort of schoolchildren that were born preterm and compare them with healthy controls. METHODS: A cohort of 147 schoolchildren, 45 born at term (≥37 weeks) and 102 very preterm (<32 weeks), was recruited and evaluated at school age (5-9 years). The Pediatric Sleep Questionnaire (PSQ) and the Sleep Disturbance Scale for Children (SDSC) were used to assess sleep disturbances in different domains. RESULTS: PSQ score was significantly higher in former preterm children (0.26 ± 0.18 vs. 0.18 ± 0.14 in controls; p = 0.004), and SDSC total score was also significantly different among groups (21.7 ± 11.6 vs. 14.1 ± 12.6; p < 0.001). Regression models showed significant mean differences in PSQ score, total SDSC score, and two SDSC subscale scores (i.e. sleep-wake transition disorders, sleep-breathing disorders, and sleep hyperhidrosis) even after adjustment for confounders. Maternal age and type of delivery were not significantly associated with total PSQ scores. CONCLUSIONS: Sleep disturbances may originate early in life since children born preterm exhibit an increased risk for developing long-term sleep problems. These findings may have important implications for management of preterm children and for implementation of early interventions focused on optimizing sleep habits.

Urinary sodium-to-potassium ratio and plasma renin and aldosterone concentrations in normotensive children: implications for the interpretation of results.

OBJECTIVES: To identify associations among the plasma renin concentration (PRC), plasma aldosterone and urinary sodium (Na)/potassium (K) ratio, and to integrate these variables into a nomogram with the aim of estimating the expected versus observed aldosterone concentration. METHODS: We studied 40 healthy normotensive children (5-8 years old, 57.5% girls) who were born at term and were adequate for their gestational age. Following overnight fasting, the PRC and plasma aldosterone in blood samples were measured, and the Na/K ratio was calculated from a simultaneously obtained urinary spot sample. A mathematical function was defined with these three variables, and a nomogram was built that would return the expected aldosterone concentration from the obtained plasma renin and urinary Na/K ratio values. RESULTS: The PRC (B =  5.9, P < 0.001) and urinary Na/K ratio (B = -98.1, P = 0.003) were significant independent predictors of plasma aldosterone. The correlation between the observed plasma aldosterone and the expected plasma aldosterone, as obtained from the nomogram, was r = 0.88, P < 0.001. The average difference between the observed and expected plasma aldosterone was -0.89, with a standard deviation of ±30%. CONCLUSION: The strong correlation between the urinary Na/K ratio, from urine samples taken at the same as the blood samples, and plasma renin and aldosterone concentrations allowed us to build a nomogram to predict aldosterone levels. This approach may be useful for evaluating the renin-angiotensin-aldosterone system (RAAS) in pediatric patients with hypertension and RAAS dysfunction.

[Assessment of the Amplicor PCR for the detection of Mycobacterium tuberculosis in smear negative respiratory and non respiratory specimens: a retrospective analysis]. / Análisis retrospectivo del rendimiento de Amplicor-PCR para la detección de Mycobacterium tuberculosis en muestras respiratorias y no respiratorias con baciloscopia negativa.

BACKGROUND: Commercial polymerase chain reaction (PCR) kits are widely accepted for analysis of smear positive respiratory specimens, but the sensitivity is variable for smear negative ones. OBJECTIVE: To assess the PCR method usefulness in smear negative respiratory and non respiratory specimens. METHODS: We compared the PCR results (AMPLICOR MTB test, Roche) of 235 specimens subjected to culture in Loewenstein-Jensen agar (as the gold standard). RESULTS: 181 (76%) were respiratory and 54 (24%) extra-respiratory specimens. The sensitivity was 88%) and 50%>, respectively, specificity and PPV was 100%> in both cases. NPV was 99.4%> in respiratory specimens and 96.1% in non-respiratory specimens. CONCLUSIONS: The good performance of this PCR in smear negative respiratory specimens allows the clinician to take decisions based on the result of this exam. In extra-respiratory specimens the contribution is important only when the PCR result is positive.

HPV16/18 genotyping for the triage of HPV positive women in primary cervical cancer screening in Chile.

BACKGROUND: We previously conducted a population-based screening trial of high-risk human papillomavirus (hrHPV) testing and conventional cytology, demonstrating higher sensitivity (92.7 % vs 22.1 % for CIN2+) but lower positive predictive value (10.5 % vs 23.9 %) of hrHPV testing. Here we report the performance of HPV16/18 genotyping to triage the hrHPV positive participants. METHODS: Women aged 25 years and older received hrHPV (Hybrid Capture 2) and Papanicolaou testing; positives by either test underwent colposcopy and directed biopsy, as did a sample of double-negatives. hrHPV positive women were reflex-tested with HPV16/18 genotyping (Digene HPV Genotyping PS Test). RESULTS: Among the 8,265 participants, 10.7 % were hrHPV positive, 1.7 % had ASCUS+ cytology, 1.2 % had CIN2+; 776 (88 %) hrHPV positive women had complete results, of whom 38.8 % were positive for HPV16 (24.0 %), HPV18 (9.7 %) or both (5.1 %). CIN2+ prevalence in HPV16/18 positive women (16.3 %, 95 % CI 12.3-20.9) was twice that of HPV16/18 negative women (8.0 %, 95 % CI 5.7-10.8). HPV16/18 genotyping identified 40.5 % of CIN2, 66.7 % of CIN3 and 75.0 % of cancers. Compared to hrHPV screening alone, HPV16/18 triage significantly reduced the referral rate (10.7 % vs 3.7 %) and the number of colposcopies required to detect one CIN2+ (9 vs 6). When HPV16/18 negative women with baseline ASCUS+ cytology were also colposcopied, an additional 14 % of CIN2+ was identified; referral increased slightly to 4.2 %. CONCLUSIONS: HPV16/18 triage effectively stratified hrHPV positive women by their risk of high-grade lesions. HPV16/18 positive women must be referred immediately; referral could be deferred in HPV16/18 negative women given the slower progression of non-HPV16/18 lesions, however, they will require active follow-up.

Variación estacional de 25-hidroxi-vitamina D3, hormona paratiroidea y fosfatasa alcalina en niños escolares / Seasonal variations in 25-hydroxy vitamin D3, parathormone and alkaline phosphatase in school-aged children

INTRODUCCIÓN: El principal rol de la vitamina D es la regulación del metabolismo del calcio, cuya principal fuen te es la vitamina D3 que se obtiene principalmente por la acción de la luz ultravioleta (UV) en la piel. OBJETIVO: Evaluar las diferencias estacionales en las concentraciones de 25-hidroxi-vitamina D3 (25OHVitD3), hormona paratiroidea (PTH), fosfatasa alcalina (FA) y calcio en niños en edad esco lar. SUJETOS Y MÉTODO: Se midieron las concentraciones de 25OHVitD3, PTH, FA y calcio en niños de 5 a 8 años, sin suplementación de Vitamina D, reclutados en Santiago de Chile (latitud -33.4372) en distintas estaciones del año. El estatus de VitD fue definido como suficiente con concentraciones de 25OHVitD3 > 20 ng/mL (50 nmol/L), insuficiente 12-20 ng/mL (30-50 nmol/L) y deficiente 20 ng/mL) en verano, lo que disminuyó significativamente en invierno (54,3%, p < 0,0001). CONCLUSIONES: Las concentraciones de 25OHVitD3 disminuyeron en aproximadamente la mitad de los niños durante el invierno, lo que se vio acompañado de un aumento de la PTH y FA, asociado a concentraciones normales de calcio. De acuerdo a nuestros resultados, la suplementación con VitD en niños podría ser necesaria durante otoño e invierno.

INTRODUCTION: The main role of Vitamin D is to regulate calcium metabolism, whose main source is vitamin D3 ob tained mostly from the action of ultraviolet (UV) light on the skin. OBJECTIVE: To evaluate the seaso nal differences in the concentrations of 25-hydroxy-vitamin D3 (25OHVitD3), parathyroid hormone (PTH), alkaline phosphatase (ALP), and calcium in school-age children. SUBJECTS AND METHOD: The concentrations of 25OHVitD3, PTH, ALP, and calcium were measured in children from Santiago, Chile (latitude -33.4372), aged 5 to 8 years, without Vitamin D supplementation, in different seasons of the year. VitD status was defined as sufficient with concentrations of 25OHVitD3 >20 ng/mL (50 nmol/L), insufficient 12-20 ng/mL (30-50 nmol/L) and deficient 20 ng/mL), which decreased significantly in winter to 54.3% (p <0.0001). CONCLUSIONS: In winter, 25OHVitD3 concentrations decreased in approximately half of the children, which was associated with an increase in PTH and ALP, and normal calcium concentrations. According to our results, children may need VitD supple mentation during fall and winter.