To screen or not to screen medical students for carriage of multidrug-resistant pathogens?

BACKGROUND: The carriage of multidrug-resistant (MDR) pathogens in medical students has not been studied extensively, despite the fact that they are in contact with patients and exposed to a hospital environment. AIM: To investigate the intestinal and nasal carriage of MDR pathogens among medical students and its association with their lifestyle and demographic data. METHODS: In 2021, first- and final-year medical students were invited to the study. Two rectal swabs were used for detection of extended-spectrum ß-lactamase (ESBL)-producing, colistin-, tigecycline- or carbapenem-resistant Gram-negative bacteria and vancomycin-resistant enterococci. Nasal swab was used for Staphylococcus aureus culture. S. aureus isolates were characterized by spa typing; Gram-negative resistant isolates and meticillin-resistant S. aureus (MRSA) were subjected to whole-genome short and/or long sequencing. FINDINGS: From 178 students, 80 (44.9%) showed nasal carriage of S. aureus; two isolates were MRSA. In rectal swabs, seven ESBL-producing strains were detected. Sixteen students were colonized by colistin-resistant bacteria, three isolates carried the mcr-1 gene (1.7%). The mcr-9 (10.7%, 19/178) and mcr-10 (2.2%, 4/178) genes were detected by quantitative polymerase chain reaction, but only two colistin-susceptible mcr-10-positive isolates were cultured. The S. aureus nasal carriage was negatively associated with antibiotic and probiotic consumption. S. aureus and colistin-resistant bacteria were detected more frequently among students in contact with livestock. CONCLUSION: Medical students can be colonized by (multi)drug-resistant bacteria with no difference between first- and final-year students. The participation of students in self-screening increases their awareness of possible colonization by resistant strains and their potential transmission due to poor hand hygiene.

Characteristics of the ID-NOW™ test for the rapid detection of SARS-CoV-2.

OBJECTIVE: To determine the sensitivity and specificity of the Abbott ID-NOW™ test in the diagnosis of COVID-19. The test is based on the detection of the SARS-CoV-2 gene by isothermal amplification technology. METHODS: From 303 individuals, two nasopharyngeal swabs and one oropharyngeal swab were collected to be tested in parallel by the ID-NOW™ test and PCR test (Allplex™ SARS-CoV-2 Assay). A subgroup of 107 individuals presented to the public collection point for covid-19 at the Motol University Hospital during the dominance of the Delta variant, and the others were tested via the Adult Emergency Admission Department during the dominance of the Omicron variant. RESULTS: Of 297 valid samples, 43 were positive by the PCR assay and 33 were positive by the ID-NOW™ test (sensitivity 76.74%; 95% CI 61.37 to 88.24%). ID-NOW™ detected three samples as positive, but the positivity was not confirmed by PCR (specificity 98.82%; 95% CI 96.59 to 99.76%). A significant increase in sensitivity up to 100% is observed for samples with a higher viral load (with a PCR threshold cycle value below 30 or from patients with symptoms of COVID-19). The Delta or Omicron variant has no significant effect on the sensitivity of the test. CONCLUSION: Due to its ease of use and speed of result, ID-NOW™ is a suitable diagnostic tool for prompt assessment of a patient's infectivity. If, despite the negative ID-NOW™ result, the patient has symptoms of COVID-19, it is advised to perform a classic PCR test for SARS-CoV-2.

The sensitivity of SARS-CoV-2 antigen tests in the view of large-scale testing.

OBJECTIVES: Antigen tests have emerged as an alternative to SARS-CoV-2 diagnostic PCR, thought to be valuable especially for the screening of bigger communities. To check appropriateness of the antigen based testing, we determined sensitivity of two point-of-care antigen tests when applied to a cohort of COVID-19 symptomatic, COVID-19 asymptomatic and healthy persons. METHODS: We examined nasopharyngeal swabs with antigen test 1 (Panbio Covid-19 Ag Rapid Test, Abbott) and antigen test 2 (Standard F Covid-19 Ag FIA, SD Biosensor). An additional nasopharyngeal and oropharyngeal swab of the same individual was checked with PCR (Allplex SARS-nCoV-2, Seegene). Within a 4-day period in October 2020, we collected specimens from 591 subjects. Of them, 290 had COVID-19 associated symptoms. RESULTS: While PCR positivity was detected in 223 cases, antigen test 1 and antigen test 2 were found positive in 148 (sensitivity 0.664, 95%CI 0.599, 0.722) and 141 (sensitivity 0.623, 95%CI 0.558, 0.684) patients, respectively. When only symptomatic patients were analysed, sensitivity increased to 0.738 (95%CI 0.667, 0.799) for the antigen test 1 and to 0.685 (95%CI 0.611, 0.750) for the antigen test 2. The substantial drop in sensitivity to 12.9% (95%CI 0.067, 0.234) was observed for samples with the PCR threshold cycle above > 30. CONCLUSIONS: Low sensitivity of antigen tests leads to the considerable risk of false negativity. It is advisable to implement repeated testing with high enough frequency if the antigen test is used as a frontline screening tool, and to follow with PCR if it is applied to vulnerable populations.

Building global development strategies for cf therapeutics during a transitional cftr modulator era.

As CFTR modulator therapy transforms the landscape of cystic fibrosis (CF) care, its lack of uniform access across the globe combined with the shift towards a new standard of care creates unique challenges for the development of future CF therapies. The advancement of a full and promising CF therapeutics pipeline remains a necessary priority to ensure maximal clinical benefits for all people with CF. It is through collaboration across the global CF community that we can optimize the evaluation and approval process of new therapies. To this end, we must identify areas for which harmonization is lacking and for which efficiencies can be gained to promote ethical, feasible, and credible study designs amidst the changing CF care landscape. This article summarizes the counsel from core advisors across multiple international regions and clinical trial networks, developed during a one-day workshop in October 2019. The goal of the workshop was to identify, in consideration of the highly transitional era of CFTR modulator availability, the drug development areas for which global alignment is currently uncertain, and paths forward that will enable advancement of CF therapeutic development.

Cystic fibrosis drug trial design in the era of CFTR modulators associated with substantial clinical benefit: stakeholders' consensus view.

CFTR modulators associated with substantial clinical benefit are expected to rapidly improve the baseline condition of people with cystic fibrosis (PWCF) as well as decrease the rate of lung function decline, the occurrence of pulmonary exacerbations and likely even other disease complications. These changes in clinical status of PWCF introduced by clinically effective modulator therapy will have major repercussions on modalities of future CF drug development. As part of its 'Strategic Plan to speed up Access to new Drugs', the European Cystic Fibrosis Society (ECFS) convened a meeting in Brussels on November 27th 2019 with relevant stakeholders (CF researchers and clinicians, patient organization and pharmaceutical company representatives, regulators, health technology assessors; see Acknowledgments for list of attendees) to discuss the future of clinical trials in cystic fibrosis (CF) in the context of HEMT entering the clinical arena. The following is the conclusion of the presentations and discussions. It is hoped that these concepts will be considered in future regulatory guidelines and may provide rationale and support for alternative trial designs.

A critical review of definitions used to describe Pseudomonas aeruginosa microbiological status in patients with cystic fibrosis for application in clinical trials.

BACKGROUND: Definition of Pseudomonas aeruginosa (Pa) microbiological status is essential for patients' inclusion in clinical trials. The aim of this study was to agree on the definitions of Pa infection status for initial infection, eradication and chronic infection to be used in clinical trials and to propose additional future study areas. METHODS: An exhaustive literature search was performed. The clinimetric properties of different definitions of Pa microbiological status were evaluated. RESULTS: Historical studies have mostly used culture-based definitions, although some have also involved complementary anti-Pa antibodies. Clinimetric analysis showed great variability in the definitions used, leading to differences in reliability, validity, responsiveness to treatment and correlation with outcome measures. Use of serology for initial Pa infection and successful Pa eradication introduced a greater level of complexity as antibody tests are not standardised. Moreover, the chronology of the immune response to Pa antigenic determinants was not completely clear. Chronic Pa infection was characterized by high levels of antibodies and good concordance between culture results and serology. CONCLUSIONS: Microbiological monitoring, regular sampling from the airways and standardization of culture methods remain essential requisites for microbiological definitions. Despite limitations, serology should be incorporated in the definitions of initial infection and eradication used in clinical trials to better classify patients at enrolment, mainly in non-expectorating children. This requires standardization of serological testing.

Microbiological diagnostics of bloodstream infections in Europe-an ESGBIES survey.

OBJECTIVES: High-quality diagnosis of bloodstream infections (BSI) is important for successful patient management. As knowledge on current practices of microbiological BSI diagnostics is limited, this project aimed to assess its current state in European microbiological laboratories. METHODS: We performed an online questionnaire-based cross-sectional survey comprising 34 questions on practices of microbiological BSI diagnostics. The ESCMID Study Group for Bloodstream Infections, Endocarditis and Sepsis (ESGBIES) was the primary platform to engage national coordinators who recruited laboratories within their countries. RESULTS: Responses were received from 209 laboratories in 25 European countries. Although 32.5% (68/209) of laboratories only used the classical processing of positive blood cultures (BC), two-thirds applied rapid technologies. Of laboratories that provided data, 42.2% (78/185) were able to start incubating BC in automated BC incubators around-the-clock, and only 13% (25/192) had established a 24-h service to start immediate processing of positive BC. Only 4.7% (9/190) of laboratories validated and transmitted the results of identification and antimicrobial susceptibility testing (AST) of BC pathogens to clinicians 24 h/day. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry from briefly incubated sub-cultures on solid media was the most commonly used approach to rapid pathogen identification from positive BC, and direct disc diffusion was the most common rapid AST method from positive BC. CONCLUSIONS: Laboratories have started to implement novel technologies for rapid identification and AST for positive BC. However, progress is severely compromised by limited operating hours such that current practice of BC diagnostics in Europe complies only partly with the requirements for optimal BSI management.

The use of broad-range bacterial PCR in the diagnosis of infectious diseases: a prospective cohort study.

OBJECTIVES: Broad-range PCR has the potential to detect virtually any bacterial species via amplification and nucleotide sequencing of a DNA region common to all bacteria. We aimed to evaluate its usefulness and clinical relevance when applied to a wide variety of primary sterile materials. METHODS: A prospective study including 1370 samples (75 heart valves, 151 joint tissue samples, 230 joint aspirates, 848 whole blood samples and 66 culture-negative cerebrospinal fluid samples) were studied by using a commercial PCR system for detecting 16S rDNA (Molzym). The PCR results were compared with culture and were considered to provide added diagnostic value only if the PCR approach revealed new pathogens that were missed by culture. RESULTS: The added value of PCR was evident in 173 of 555 PCR-positive samples (0.126; 0.109-0.144 (proportion from all tested samples; 95% confidence interval)), most frequently in examinations of heart valves (0.56; 0.448-0.672) and joint tissue samples (0.219; 0.153-0.284). In contrast, the lowest rate of PCR with added value was noted for blood samples, regardless of the patient cohort they had been drawn from (nononcologic patients from intensive care: 0.065; 0.043-0.087, haematooncologic children: 0.048; 0.027-0.070). Moreover, PCR missed up to 7.1% of blood culture findings (0.071; 0.048-0.095) regarded as clinically relevant, which was the second highest failure rate after joint tissue samples (0.099; 0.052-0.147). CONCLUSIONS: Broad-range PCR substantially increases detection rate of pathogens, especially from heart valves and joint samples. However, a concurrent risk of false-negative PCR results justifies the need for parallel culture.

Increasing incidence of Clostridium difficile ribotype 001 associated with severe course of the infection and previous fluoroquinolone use in the Czech Republic, 2015.

The aim of the study was to provide an update on the epidemiology of C. difficile infection (CDI) in a representative number of hospitals within the Czech Republic in 2015. In 2015, twenty-eight Czech hospitals were invited to participate in a CDI study. Laboratories sent the first 20 consecutive C. difficile isolates for characterization by capillary-electrophoresis (CE) ribotyping and the presence of toxin genes and collected patient data on previous hospitalization, antibiotic treatment, the number of CDI episodes and the course of CDI. The mean incidence of CDI was 5.2 [95% CI 4.2-6.2] cases per 10,000 patient-bed days in 27 hospitals in 2015. Of 490 C. difficile isolates, the prevalent PCR ribotypes (RTs) were 001 (n = 164, 33.5%) and 176 (n = 125, 25.5%) followed by 014 (n = 37, 7.6%), 012 (n = 17, 3.5%), 020 (n = 16, 3.3%), 017 (n = 14, 2.9%) and 002 (n = 11, 2.2%). A severe course of CDI was reported in 104 cases (21.2%) with significant association with RT001 infection (p = 0.03). CDI recurrence was 10.8% (n = 53). The previous use of fluoroquinolones was associated with RTs 001 and 176 CDIs (p = 0.046 and p = 0.041). We observed a persistence of RTs 001 and 176 CDIs in the Czech Republic that was associated with the previous use of fluoroquinolones. This highlights the need for a reduction in fluoroquinolone use in Czech hospital settings.

How and why to monitor Pseudomonas aeruginosa infections in the long term at a cystic fibrosis centre.

BACKGROUND: Pseudomonas aeruginosa is a major cystic fibrosis (CF) pathogen causing chronic respiratory infections and posing a risk for cross-infection between patients with CF. AIM: To propose an algorithm for long-term surveillance of P. aeruginosa and assess its suitability for monitoring the epidemiological situation at a CF centre with approximately 300 patients. METHODS: Over a nine-year period, over 300 P. aeruginosa isolates from 131 infected patients were tested by multi-locus sequence typing (MLST) and/or random amplified polymorphic DNA (RAPD) assay. FINDINGS: MLST analysis led to the identification of 97 different sequence types which were distributed among 17 RAPD-generated (pseudo)clusters. This indicates that the easy-to-perform RAPD assay is only suitable for intra-individual, not interindividual, strain analyses. No epidemic strains were observed. Longitudinal analysis revealed that 110 of the 131 patients were infected with the same strain over the observation period, whereas 21 patients had a strain replacement or a new infection. Chronic infection was found in 99 of the 131 patients, and the remaining 32 patients met the criteria for intermittent infection (as defined by the Leeds criteria). Eighteen of the 32 patients (56%) with intermittent infection were infected with the same strain for up to nine years. CONCLUSION: The strain type only changed in 16% of 131 patients with chronic or intermittent infection. As many as 56% of patients considered to have intermittent infection were actually chronically infected with the same strain for many years.

[Bacteria of the Burkholderia cepacia complex: epidemiology and diagnosis of infection in patients with cystic fibrosis]. / Bakterie komplexu Burkholderia cepacia - epidemiologie a diagnostika infekcí u pacientu s cystickou fibrózou.

UNLABELLED: Bacteria of the Burkholderia cepacia complex are the cause of severe lung infections primarily in patients with cystic fibrosis (CF). The risk of epidemic spread of the pathogen in the community of CF patients was the reason for implementing strict isolation measures and identifying the bacterium as early as possible. This review article features the taxonomy of the Burkholderia cepacia complex, possibilities for the laboratory diagnosis of all representatives of this complex, and epidemiological situation in the communities of CF patients in the Czech Republic and in the world. KEYWORDS: Burkholderia cepacia complex - cystic fibrosis - epidemic strain - pathogenesis of the infection.

DNA profiling of Stenotrophomonas maltophilia by PCR targeted to its species-specific repetitive palindromic sequences.

AIMS: The aim of this study was to develop a simple protocol for a PCR-based fingerprinting of Stenotrophomonas maltophilia (SmrepPCR) that utilizes primers complementary to repetitive extragenic palindromic elements (REPs) of this micro-organism. METHODS AND RESULTS: The relatedness of 34 isolates of environmental and clinical origin was investigated by two SmrepPCRs with two different primers, gyrB sequencing and XbaI macrorestriction followed by pulsed-field gel electrophoresis. While SmrepPCR (with primer DIR) results matched data obtained from the analysis of gyrB nucleotide sequences and identified several clonal complexes, XbaI macrorestriction showed high level of heterogeneity between isolates. The macrorestriction-based clustering of isolates did not correspond to both gyrB and DIR-SmrepPCR grouping. CONCLUSIONS: Our results show that SmrepPCR-inferred relationship of isolates is in a good agreement with sequence-based methods. The combined information from all methods used suggests that rapid evolution of S. maltophilia genomes might be predominantly due to high rate of rearrangements caused by mobile genetic elements. SIGNIFICANCE AND IMPACT OF THE STUDY: The presented method is an inexpensive and easy to perform alternative to genotype S. maltophilia isolates and to study their population genetics. SmrepPCR demonstrates the usefulness of species-specific repetitive elements in genomic analyses.

Recommendations for the classification of diseases as CFTR-related disorders.

Several diseases have been clinically or genetically related to cystic fibrosis (CF), but a consensus definition is lacking. Here, we present a proposal for consensus guidelines on cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (CFTR-RDs), reached after expert discussion and two dedicated workshops. A CFTR-RD may be defined as "a clinical entity associated with CFTR dysfunction that does not fulfil diagnostic criteria for CF". The utility of sweat testing, mutation analysis, nasal potential difference, and/or intestinal current measurement for the differential diagnosis of CF and CFTR-RD is discussed. Algorithms which use genetic and functional diagnostic tests to distinguish CF and CFTR-RDs are presented. According to present knowledge, congenital bilateral absence of vas deferens (CBAVD), acute recurrent or chronic pancreatitis and disseminated bronchiectasis, all with CFTR dysfunction, are CFTR-RDs.

Burkholderia cenocepacia in cystic fibrosis: epidemiology and molecular mechanisms of virulence.

Burkholderia cepacia complex (Bcc) bacteria have gained notoriety as pathogens in cystic fibrosis (CF) because they are difficult to identify and treat, and also have the ability to spread between CF individuals. Of the 17 formally named species within the complex, Burkholderia multivorans and Burkholderia cenocepacia dominate in CF. Multilocus sequence typing has proven to be a very useful tool for tracing the global epidemiology of Bcc bacteria and has shown that B. cenocepacia strains with high transmissibility, such as the ET-12 strain (ST-28) and the Czech strain (ST-32), have spread epidemically within CF populations in Canada and Europe. The majority of research on the molecular pathogenesis of Bcc bacteria has focused on the B. cenocepacia ET-12 epidemic lineage, with gene mutation, genome sequence analysis and, most recently, global gene expression studies shedding considerable light on the virulence and antimicrobial resistance of this pathogen. These studies demonstrate that the ability of B. cenocepacia to acquire foreign DNA (genomic islands, insertion sequences and other mobile elements), regulate gene expression via quorum sensing, compete for iron during infection, and mediate antimicrobial resistance and inflammation via its membrane and surface polysaccharides are key features that underpin the virulence of different strains. With the wealth of molecular knowledge acquired in the last decade on B. cenocepacia strains, we are now in a much better position to develop strategies for the treatment of pathogenic colonization with Bcc and to answer key questions on pathogenesis concerning, for example, the factors that trigger the rapid clinical decline in CF patients.

Longitudinal observation of enterovirus and adenovirus in stool samples from Norwegian infants with the highest genetic risk of type 1 diabetes.

BACKGROUND: Enterovirus and adenovirus are common in infancy, causing mostly asymptomatic infections. However, even an asymptomatic infection may be associated with increased risk of development of certain chronic non-infectious diseases, as has been suggested for enterovirus and type 1 diabetes. Data on occurrence and course of the infections in infancy are therefore important for designing effective approaches towards study of the association. OBJECTIVES: To estimate the frequency of enterovirus and adenovirus infections in Norwegian infants, to evaluate the duration of the infections, to investigate their association with symptoms, and to establish a robust procedure that will be used to study the association between these viruses and the development of auto-immunity leading to type 1 diabetes. STUDY DESIGN: Parents of infants, recruited for a study on environmental triggers of type 1 diabetes, submitted monthly samples of infant faeces, as well as information on symptoms of infection. The samples were analysed for enterovirus and adenovirus using quantitative real-time PCR, and enterovirus-positive samples were sequenced. RESULTS: Enteroviruses were found in 142/1,255 (11.3%), and adenoviruses in 138/1,255 (11.0%) of stool samples. Approximately half of the infants were exposed to these viruses at least once during the first year of observation (period 3-14 months of age). The presence of adenovirus was associated with fever and with symptoms of cold but not with diarrhoea and vomiting. The enterovirus positivity was not associated with any symptoms. CONCLUSIONS: The prevalence of enterovirus and adenovirus in longitudinally obtained faecal samples from infants is sufficiently high to enable studies of their association with chronic diseases. The present protocol for evaluating exposure to these viruses is well suited for large-scale efforts aimed at assessing possible long-term consequences, particularly in relation to type 1 diabetes.

[Type I diabetes mellitus and associated autoimmune diseases in the first-degree relatives of diabetic children: questionnaire based study]. / Diabetes mellitus 1. typu a sdruzená autoimunitní onemocnení u prvostupnových príbuzných diabetických deti: výsledky dotazníkové studie.

BACKGROUND: Type 1 diabetes mellitus (T1DM) is associated with increased incidence of other autoimmune diseases. The shared genetic background may play a role in the disease pathogenesis. The aim of our study was to assess the prevalence of T1DM and other autoimmune disorders in the first-degree relatives of diabetic children. METHODS AND RESULTS: Data were retrospectively obtained using structured questionnaires from 868 diabetic children younger than 18 years (434 girls and 434 boys, age 12.5 +/- 4.0, mean +/- SD) and their 2704 relatives. The control group included 1466 non-diabetic schoolmates and friends (796 girls, 670 boys, age 11.9 +/- 4.5) and their 4510 first-degree relatives. In the questionnaire we asked about occurrence of thyroid and celiac disease in cases and controls, and about occurrence of T1DM, thyroid and celiac disease in their first-degree relatives. We observed significantly higher prevalence of T1DM in fathers (4.4% vs. 0.8%), mothers (2.0% vs. 0.5%) and siblings (2.5% vs. 0%) of diabetic children compared to controls. Thyroid disease was found significantly more in diabetic children (10.0% vs. 1.9%) and their siblings (3.1% vs. 1.7%). Prevalence of celiac disease was also higher in diabetic children than in controls (3.2% vs. 0.5%), but it does not differ in their first-degree relatives. CONCLUSIONS: We found significantly higher prevalence of thyroid and celiac disease in T1DM children than in controls. Targeted screening and early detection of thyroid and celiac diseases in T1DM patients are likely to be necessary. We observed an increased prevalence of T1DM and thyroid disease in first-degree relatives of diabetic children, however screening of autoimmune diseases associated with T1DM in the first-degree relatives remain controversial.

[Association of insulin gene variants with type 1 diabetes mellitus in Czech population]. / Asociace variant inzulínového genu s diabetes mellitus 1. typu v ceské detské populaci.

BACKGROUND: The objective of the study was to quantify the association of insulin gene variants with type 1 diabetes mellitus (TIDM) in the Czech population. METHODS AND RESULTS: In an association study, we compared genotypes of 332 T1DM patients (age at T1DM onset was 8.1 +/- 4.4 yrs) with 292 healthy nondiabetic controls of similar age. All subjects were previously genotyped for HLA-DQB1, -DQA1 polymorphisms and DRB1*04 subtypes. The insulin gene was typed using the -23 HphI single nucleotide polymorphism after we had demonstrated a nearly complete linkage disequilibrium between this polymorphism, and the etiological VNTR in the Czech population. The protective variant of the insulin gene was present in 24% T1DM patients, and in 48% controls (OR=0.34, CI 95% 0.24-0.48), a risk comparable to weaker-associated HLA-DQ alleles. The association was independent of the HLA-conferred T1DM risk. The insulin gene polymorphism had no influence on the age at T1DM onset. CONCLUSIONS: We conclude that the insulin gene genotyping confers important information on T1DM risk in our population, and should be used in determining the disease risk along with the HLA-DQ typing.

Higher maternal age at delivery, and lower birth orders are associated with increased risk of childhood type 1 diabetes mellitus.

In several populations, maternal age at delivery and birth order have been demonstrated to variously affect the risk of Type 1 diabetes mellitus in the offspring. The aim of the present study was to investigate this relation in the Czech population. Questionnaire data on 640 children with childhood-onset Type 1 DM and data on 50 random controls to each case, obtained from the national Birth Registry and matched for the calendar year of birth, were analysed using multivariate logistic regression. The risk of Type 1 DM increases with higher maternal age at birth of the child (OR = 1.07, CI 95 % 1.05 - 1.09 per one year increment), and decreases with higher birth order (OR = 0.70, CI 95 % 0.62 - 0.79 per increment in birth order). There was no significant difference in these effects across the five-years bands of age at diabetes onset. We detected no independent effect of maternal education, either. Our study provides further evidence that the risk of Type 1 diabetes in the offspring increases with higher maternal age at delivery and lower birth order.

HLA-DQ polymorphisms modify the risk of thyroid autoimmunity in children with type 1 diabetes mellitus.

OBJECTIVE: Type 1 diabetes mellitus (DM1) is frequently accompanied by thyroid autoimmunity (TAI). The aims of the present study were to estimate the prevalence of TAI and to determine the contribution of HLA-DQA1 and -DQB1 polymorphisms to TAI susceptibility among children with DM1. PATIENTS AND METLHODS: Screening for TAI was performed in 285 children with DM1 by measuring autoantibodies against thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg). HLA-DQA1 and -DQB1 were genotyped using PCR-SSP. RESULTS: Repeated positivity of anti-TPO and/or anti-Tg was found in 45/285 children with DM1 (15.8%). The prevalence was significantly higher in girls than in boys (26.7% vs 6.7%; p<10(-5)). The HLA-DQB1*0302 allele conferred susceptibility to TAI in children with DM1 (OR 2.7, 95% CI 1.1-6.4), while the DQB1*05 alleles acted protectively (OR 0.2, CI 95% 0.08-0.7). CONCLUSIONS: HLA-DQ polymorphisms significantly modify the risk of TAI in children with DM1.

[Prediction of type 1 diabetes mellitus in first degree Czech relatives of diabetic patients]. / Predikce diabetes mellitus 1. typu u ceských prvostupnových príbuzných diabetických pacientu.

Diagnosis of autoimmune beta cell destruction by genetic risk analysis, autoantibody evaluation and the test of stimulated insulin secretion performance in first-degree relatives of diabetic patients. 208 Czech children and adults (101 boys and 107 girls, 186 siblings, 22 offspring of diabetic parents, aged 1-22 years, mean age 11.5 +/- 5.4 years) were enrolled in the study. Complete DQB1, DQA1 typing and DRB1*04 subtyping were performed by the PCR in 202 subjects. Sera of all children were investigated for anti-GAD65, anti-IA2 and insulin antibodies using RIA methods. The cut-off normal levels were determined as the 99th percentile of 105 non-diabetic children. IVGTT was performed in children with significant titre of one or more autoantibodies. Total level of stimulated insulin secretion < 48 mU/l was assessed as defect of FPIR. Risk genotype DQA1*05-DQB1*0201/DQA1*03-DQB1*0302 (OR = 100, CI 95% 13-730) was found in 24 of 202 first-degree relatives (12%). 22 children (11%) carried strong protective allele DQB1*0602 (OR = 0.03, CI 95% 0.01-0.12). Autoantibody positivity was recognised in 9 of 208 children (2.9%) and IVGTT was performed. Positivity of anti-GAD65, anti-IA2 or IAA was identified in 5 of 24 children with the highest risk genotype (21%) and in 4 children of 113 with lower risk or neutral genotypes (3.5%). Borderline positivity of one autoantibody was found in 1 boy with the highest risk genotype and in 2 children with lower risk genotypes. Only temporary anti-GAD65 positivity was found in girl with protective genotype. Type 1 diabetes mellitus was diagnosed in boy during IVGTT and disease manifested 6 months after IVGTT in girl with defect of FPIR. Standardised methods for prediction of Type 1 diabetes were introduced in first-degree relatives of diabetic patients. These methods are used for Czech registry of diabetic children.