Age-period-cohort modelling of type 1 diabetes incidence rates among children included in the EURODIAB 25-year follow-up study

AIMS

Specific patterns in incidence may reveal environmental explanations for type 1 diabetes incidence. We aimed to study type 1 diabetes incidence in European childhood populations to assess whether an increase could be attributed to either period or cohort effects.

METHODS

Nineteen EURODIAB centres provided single year incidence data for ages 0-14 in the 25-year period 1989-2013. Case counts and person years were classified by age, period and cohort (APC) in 1-year classes. APC Poisson regression models of rates were fitted using restricted cubic splines for age, period and cohort per centre and sex. Joint models were fitted for all centres and sexes, to find a parsimonious model.

RESULTS

A total of 57,487 cases were included. In ten and seven of the 19 centres the APC models showed evidence of nonlinear cohort effects or period effects, respectively, in one or both sexes and indications of sex-specific age effects. Models showed a positive linear increase ranging from approximately 0.6 to 6.6%/year. Centres with low incidence rates showed the highest overall increase. A final joint model showed incidence peak at age 11.6 and 12.6 for girls and boys, respectively, and the rate-ratio was according to sex below 1 in ages 5-12.

CONCLUSION

There was reasonable evidence for similar age-specific type 1 diabetes incidence rates across the EURODIAB population and peaks at a younger age for girls than boys. Cohort effects showed nonlinearity but varied between centres and the model did not contribute convincingly to identification of environmental causes of the increase.

Novel glucokinase gene mutation in the first Macedonian family tested for MODY

We present a boy with mild hyperglycemia detected during an upper respiratory infection. Novel splicing mutation in the intron 1 of the GCK gene (c.45+1G>A) was detected, and was subsequently confirmed in his father. This is the first case of genetically confirmed Macedonian family with MODY.

Seasonal variation in month of diagnosis in children with type 1 diabetes registered in 23 European centers during 1989-2008: little short-term influence of sunshine hours or average temperature

BACKGROUND

The month of diagnosis in childhood type 1 diabetes shows seasonal variation.

OBJECTIVE

We describe the pattern and investigate if year-to-year irregularities are associated with meteorological factors using data from 50 000 children diagnosed under the age of 15 yr in 23 population-based European registries during 1989-2008.

METHODS

Tests for seasonal variation in monthly counts aggregated over the 20 yr period were performed. Time series regression was used to investigate if sunshine hour and average temperature data were predictive of the 240 monthly diagnosis counts after taking account of seasonality and long term trends.

RESULTS

Significant sinusoidal pattern was evident in all but two small centers with peaks in November to February and relative amplitudes ranging from ± 11 to ± 38% (median ± 17%). However, most centers showed significant departures from a sinusoidal pattern. Pooling results over centers, there was significant seasonal variation in each age-group at diagnosis, with least seasonal variation in those under 5 yr. Boys showed greater seasonal variation than girls, particularly those aged 10-14 yr. There were no differences in seasonal pattern between four 5-yr sub-periods. Departures from the sinusoidal trend in monthly diagnoses in the period were significantly associated with deviations from the norm in average temperature (0.8% reduction in diagnoses per 1 °C excess) but not with sunshine hours.

CONCLUSIONS

Seasonality was consistently apparent throughout the period in all age-groups and both sexes, but girls and the under 5 s showed less marked variation. Neither sunshine hour nor average temperature data contributed in any substantial way to explaining departures from the sinusoidal pattern.

The effect of exogenous 24-epibrassinolide on the ecdysteroid content in the leaves of Spinacia oleracea L

The aim of this study was to show whether/how the application of exogenous 24-epibrassinolide can affect the content of ecdysteroids in spinach leaves. Brassinosteroids and ecdysteroids, structurally related phytosterols, show effect on a range of processes in plants. Brassinosteroids increase biomass yield in some species, photosynthesis and resistance to stress, and ecdysteroids show effect on proteins responsible for binding of CO2 or water cleavage. The mutual interaction of these sterols in plants is unclear. The UPLC-(+)ESI-MS/MS analyses of extracts of treated and untreated spinach (Spinacia oleracea L.) leaves show that the application of exogenous 24-epibrassinolide does influence the ecdysteroid content in plant tissues. The response differs for the major ecdysteroids and also differs from that for the minor ones and is dependent on the developmental stage of the leaves within the same plant or the 24-epibrassinolide concentration applied.

Trends in childhood type 1 diabetes incidence in Europe during 1989-2008: evidence of non-uniformity over time in rates of increase

AIMS/HYPOTHESIS

The aim of the study was to describe 20-year incidence trends for childhood type 1 diabetes in 23 EURODIAB centres and compare rates of increase in the first (1989-1998) and second (1999-2008) halves of the period.

METHODS

All registers operate in geographically defined regions and are based on a clinical diagnosis. Completeness of registration is assessed by capture-recapture methodology. Twenty-three centres in 19 countries registered 49,969 new cases of type 1 diabetes in individuals diagnosed before their 15th birthday during the period studied.

RESULTS

Ascertainment exceeded 90% in most registers. During the 20-year period, all but one register showed statistically significant changes in incidence, with rates universally increasing. When estimated separately for the first and second halves of the period, the median rates of increase were similar: 3.4% per annum and 3.3% per annum, respectively. However, rates of increase differed significantly between the first half and the second half for nine of the 21 registers with adequate coverage of both periods; five registers showed significantly higher rates of increase in the first half, and four significantly higher rates in the second half.

CONCLUSIONS/INTERPRETATION

The incidence rate of childhood type 1 diabetes continues to rise across Europe by an average of approximately 3-4% per annum, but the increase is not necessarily uniform, showing periods of less rapid and more rapid increase in incidence in some registers. This pattern of change suggests that important risk exposures differ over time in different European countries. Further time trend analysis and comparison of the patterns in defined regions is warranted.

Target setting in intensive insulin management is associated with metabolic control: the Hvidoere childhood diabetes study group centre differences study 2005

OBJECTIVE

To evaluate glycaemic targets set by diabetes teams, their perception by adolescents and parents, and their influence on metabolic control.

METHODS

Clinical data and questionnaires were completed by adolescents, parents/carers and diabetes teams in 21 international centres. HbA1c was measured centrally.

RESULTS

A total of 2062 adolescents completed questionnaires (age 14.4 +/- 2.3 yr; diabetes duration 6.1 +/- 3.5 yr). Mean HbA 1c = 8.2 +/- 1.4% with significant differences between centres (F = 12.3; p < 0.001) range from 7.4 to 9.1%. There was a significant correlation between parent (r = 0.20) and adolescent (r = 0.21) reports of their perceived ideal HbA1c and their actual HbA1c result (p < 0.001), and a stronger association between parents' (r = 0.39) and adolescents' (r = 0.4) reports of the HbA1c they would be happy with and their actual HbA1c result. There were significant differences between centres on parent and adolescent reports of ideal and happy with HbA1c (8.1 < F > 17.4;p < 0.001). A lower target HbA1c and greater consistency between members of teams within centres were associated with lower centre HbA1c (F = 16.0; df = 15; p < 0.001).

CONCLUSIONS

Clear and consistent setting of glycaemic targets by diabetes teams is strongly associated with HbA1c outcome in adolescents. Target setting appears to play a significant role in explaining the differences in metabolic outcomes between centres.

Methodological and organizational aspects of newborn screening for congenital hypothyroidism in Macedonia

Congenital hypothyroidism (CH) is the most common preventable cause of mental retardation. Early diagnosis and treatment are crucial to the prevention of severe intellectual deficit. Neonatal screening in a blood spot from the heel of the newborn between the 2nd and 5th day after birth and determination of thyroid stimulation hormone (TSH) level by fluoroimmunoassay (DELFIA method) is the commonly used approach for the timely detection and therapy of congenital hypothyroidism. Over the period April 2002 - December 2004 results of 27,782 samples were analysed. They were obtained from 5 hospitals in the Republic of Macedonia (Obstetrics and Gynaecology Clinic, Clinical Centre, Skopje; Cair Obstetrics and Gynaecology Hospital, Mala Bogorodica Hospital and hospitals within the cities of Bitola and Prilep). Over the period January 2005 - December 2007 the analysis of 50,732 samples covered all obstetrics hospitals in Macedonia. For the first period analysed (April 2002 - December 2004) we evaluated the sensitivity and specificity of the biochemical method applied for neonatal screening for CH. In our study TSH was assayed by DELFIA fluorometric kits. The cut-off value in our laboratory was 15 mU/L. We compared coverage, timeliness of programme indicators (age at sampling, recall and treatment initiation, timing of specimen delivery and laboratory results) and specimen quality with international standards. Recall rate, sensitivity, specificity, positive predictive values and relative incidence rate for CH were calculated. The established method was deemed highly sensitive and highly specific. During the period of analysis in our study, 28 cases were detected or an incidence rate of 1 : 2,804 was calculated. Treatment was initiated on the 13th day on average (between the 5th and 35th day).

Are family factors universally related to metabolic outcomes in adolescents with Type 1 diabetes?

AIMS

To assess the importance of family factors in determining metabolic outcomes in adolescents with Type 1 diabetes in 19 countries.

METHODS

Adolescents with Type 1 diabetes aged 11-18 years, from 21 paediatric diabetes care centres, in 19 countries, and their parents were invited to participate. Questionnaires were administered recording demographic data, details of insulin regimens, severe hypoglycaemic events and number of episodes of diabetic ketoacidosis. Adolescents completed the parental involvement scale from the Diabetes Quality of Life for Youth--Short Form (DQOLY-SF) and the Diabetes Family Responsibility Questionnaire (DFRQ). Parents completed the DFRQ and a Parental Burden of Diabetes score. Glycated haemoglobin (HbA(1c)) was analysed centrally on capillary blood.

RESULTS

A total of 2062 adolescents completed a questionnaire, with 2036 providing a blood sample; 1994 parents also completed a questionnaire. Family demographic factors that were associated with metabolic outcomes included: parents living together (t = 4.1; P < 0.001), paternal employment status (F = 7.2; d.f. = 3; P < 0.001), parents perceived to be over-involved in diabetes care (r = 0.11; P < 0.001) and adolescent-parent disagreement on responsibility for diabetes care practices (F = 8.46; d.f. = 2; P < 0.001). Although these factors differed between centres, they did not account for centre differences in metabolic outcomes, but were stronger predictors of metabolic control than age, gender or insulin treatment regimen.

CONCLUSIONS

Family factors, particularly dynamic and communication factors such as parental over-involvement and adolescent-parent concordance on responsibility for diabetes care appear be important determinants of metabolic outcomes in adolescents with diabetes. However, family dynamic factors do not account for the substantial differences in metabolic outcomes between centres.

Implementation of Fluorescent in situ hybridization (FISH) as a method for detecting microdeletion syndromes - our first experiences

Fluorescent in situ hybridisation (FISH) is a complementary cytogenetic method which has an important role in discovering unsolved cases of mental retardation and multiple anomalies. The ability of this method to detect complex and cryptic chromosomal rearrangements exceeds the resolution of the usual cytogenetic banding techniques; therefore it has a wide implementation in modern cytogenetic laboratories - in routine work, as well as for research purposes. We analysed 19 patients with microdeletion syndromes - 9 patients with Williams syndrome, 4 patients with Prader-Willi syndrome, and 6 patients with DiGeorge syndrome. On the basis of evaluation of facial dysmorphism and the presence of specific major anomalies, all the patients met the criteria for the diagnosis of the syndrome. FISH studies were performed, confirming the suspected syndrome in patients.

Premature thelarche in Macedonia: a three-year follow-up

INTRODUCTION

Premature thelarche presents as an appearance of breasts and glandular tissue in girls before the age of 8 years. It is mostly a benign and transitory variation of premature sexual development.

AIM OF THE STUDY

We evaluated a group of girls with premature thelarche for clinical and auxologic characteristics for a period of three years. We investigated the duration of the condition and eventual progression toward true idiopathic central precocious puberty.

PATIENTS, MATERIALS, METHODS

At the Department of Endocrinology and Genetics at the Pediatric Clinic in Skopje, 127 girls with premature thelarche, from all over the country, were analyzed and followed-up for a period of 3 years (2000-2003).

RESULTS AND CONCLUSIONS

Premature thelarche as a partial form of premature sexual development, in our study included 98 girls, and showed to be a benign condition, the girls are with normal height, slightly elevated weight, but with increased bone maturation and height velocity in the first year. A progression toward central precocious puberty was not registered. The duration of the condition was about two years in most of the girls, with a regression of enlarged breasts in smaller patients and with occurrence of normal puberty in older patients (Tab. 1, Fig. 3, Ref. 16). Full Text (Free, PDF) www.bmj.sk.

Girls with Turner's syndrome with spontaneous menarche have an increased risk of endometrial carcinoma: a case report and review from the literature

BACKGROUND

Patients with Turner's syndrome receiving unopposed estrogens for the induction of feminization have an increased risk of endometrial carcinoma. Only seven patients who were not treated with estrogen replacement therapy have been reported to have developed endometrial carcinoma at different age levels.

CASE

A young girl with Turner's syndrome phenotype, spontaneous puberty, and karyotype 45,X0/47,XXX from peripheral blood, after irregular menstrual cycles of 9 years, at the age of 21, was diagnosed with a non-invasive well-differentiated endometrial carcinoma confined to a hyperplastic endometrial polyp. Analysis of the ovarian tissue by FISH confirmed mosaicism: 45,X0/46,XX/47,XXX.

CONCLUSION(S)

The endogenous estrogen secretion from the ovaries might have caused malignancy in this case. Patients with Turner's syndrome with spontaneous menarche might carry a higher risk of endometrial carcinoma.

Pituitary pseudotumor with unusual presentation reversed shortly after the introduction of thyroxine replacement therapy

Pituitary pseudotumor (pituitary thyrotroph hyperplasia) caused by unrecognized and untreated hypothyroidism has been described as a rare condition, mostly in adults. There are only a few reports on this condition in children. Here we describe an unusual association of pituitary pseudotumor with hypothyroidism, vaginal bleeding, and growth retardation in a girl at an early stage of puberty. Hormonal testing showed low thyroxine and high TSH levels, hyperprolactinemia, low growth hormone levels and prepubertal levels of gonadotrophins. Ovarian cyst was detected by ultrasound. A large intrasellar mass expanding beyond the sella turcica was detected on MRI. Homogeneous contrast enhancement confirmed pituitary hyperplasia. Therapy with L-thyroxine resulted in rapid improvement of the clinical signs, normalization of the hormone levels, and resolution of the pituitary hyperplasia on MRI within 40 days. In children, prolonged unrecognized primary hypothyroidism might be accompanied by growth deficiency and pubertal disharmony. Pituitary hyperplasia should be sought in these cases.

Good metabolic control is associated with better quality of life in 2,101 adolescents with type 1 diabetes

OBJECTIVE

It is unclear whether the demands of good metabolic control or the consequences of poor control have a greater influence on quality of life (QOL) for adolescents with diabetes. This study aimed to assess these relations in a large international cohort of adolescents with diabetes and their families.

RESEARCH DESIGN AND METHODS

The study involved 2,101 adolescents, aged 10-18 years, from 21 centers in 17 countries in Europe, Japan, and North America. Clinical and demographic data were collected from March through August 1998. HbA(1c) was analyzed centrally (normal range 4.4-6.3%; mean 5.4%). Adolescent QOL was assessed by a previously developed Diabetes Quality of Life (DQOL) questionnaire for adolescents, measuring the impact of diabetes, worries about diabetes, satisfaction with life, and health perception. Parents and health professionals assessed family burden using newly constructed questionnaires.

RESULTS

Mean HbA(1c) was 8.7% (range 4.8-17.4). Lower HbA(1c) was associated with lower impact (P < 0.0001), fewer worries (P < 0.05), greater satisfaction (P < 0.0001), and better health perception (P < 0.0001) for adolescents. Girls showed increased worries (P < 0.01), less satisfaction, and poorer health perception (P < 0.01) earlier than boys. Parent and health professional perceptions of burden decreased with age of adolescent (P < 0.0001). Patients from ethnic minorities had poorer scores for impact (P < 0.0001), worries (P < 0.05), and health perception (P < 0.01). There was no correlation between adolescent and parent or between adolescent and professional scores.

CONCLUSIONS

In a multiple regression model, lower HbA(1c) was significantly associated with better adolescent-rated QOL on all four subscales and with lower perceived family burden as assessed by parents and health professionals.

Persistent differences among centers over 3 years in glycemic control and hypoglycemia in a study of 3,805 children and adolescents with type 1 diabetes from the Hvidøre Study Group

OBJECTIVE

Twenty-one international pediatric diabetes centers from 17 countries investigated the effect of simple feedback about the grand mean HbA(1c) level of all centers and the average value of each center on changes in metabolic control, rate of severe hypoglycemia, and insulin therapy over a 3-year period.

RESEARCH DESIGN AND METHODS

Clinical data collection and determination of HbA(1c) levels were conducted at a central location in 1995 (n = 2,780, age 0-18 years) and 1998 (n = 2,101, age 11-18 years).

RESULTS

Striking differences in average HbA(1c) concentrations were found among centers; these differences remained after adjustment for the significant confounders of sex, age, and diabetes duration. They were apparent even in patients with short diabetes duration and remained stable 3 years later (mean adjusted HbA(1c) level: 8.62 +/- 0.03 vs. 8.67 +/- 0.04 [1995 vs. 1998, respectively]). Three centers had improved significantly, four centers had deteriorated significantly in their overall adjusted HbA(1c) levels, and 14 centers had not changed in glycemic control. During the observation period, there were increases in the adjusted insulin dose by 0.076 U/kg, the adjusted number of injections by 0.23 injections per day, and the adjusted BMI by 0.95 kg/m(2). The 1995 versus 1998 difference in glycemic control for the seven centers could not be explained by prevailing insulin regimens or rates of hypoglycemia.

CONCLUSIONS

This study reveals significant outcome differences among large international pediatric diabetes centers. Feedback and comparison of HbA(1c) levels led to an intensification of insulin therapy in most centers, but improved glycemic control in only a few.

Naturally occurring amino acid substitutions at Arg1174 in the human insulin receptor result in differential effects on receptor biosynthesis and hybrid formation, leading to discordant clinical phenotypes

Missense mutations in the tyrosine kinase domain of the human insulin receptor frequently result in a dominantly inherited form of insulin resistance. We noted a marked disparity in the clinical phenotypes of our study subjects with different missense mutations at the same residue (Arg1174) of the insulin receptor. Subjects with a tryptophan substitution (W) were only moderately hyperinsulinemic, whereas those with a glutamine substitution (Q) had severe clinical and biochemical insulin resistance. Studies were undertaken to explore the molecular mechanisms underlying these differences. Both W and Q mutant receptors bound insulin normally but were kinase inactive. The W mutation resulted in more rapid degradation of newly synthesized mutant receptor, which contrasted with the near-normal biosynthesis of the Q receptor. The propensity of the W receptor to form hybrids with the cotransfected wild-type (WT) receptor was also markedly impaired compared with the Q receptor, to an extent greater than could be explained by lower steady-state expression. Thus, the more clinically benign consequences of the heterozygous W mutant receptor are likely to relate to its impaired biosynthesis and/or reduced capacity to form hybrids with WT receptors. In addition to providing an explanation for the milder phenotype of 1174W versus 1174Q carriers, these studies provide further support for the notion that the dominant-negative effect of insulin receptor tyrosine kinase mutations involves the competition between inactive mutant homodimers and WT/mutant hybrids with active WT homodimers for both ligands and intracellular substrates.

Insulin management and metabolic control of type 1 diabetes mellitus in childhood and adolescence in 18 countries. Hvidøre Study Group on Childhood Diabetes

Insulin regimens and metabolic control in children and adolescents with Type 1 diabetes mellitus were evaluated in a cross-sectional, non-population-based investigation, involving 22 paediatric departments, from 18 countries in Europe, Japan, and North America. Blood samples and information were collected from 2873 children from March to August 1995. HbA1c was determined once and analysed centrally (normal range 4.4-6.3%, mean 5.4%). Year of birth, sex, duration of diabetes, height, body weight, number of daily insulin injections, types and doses of insulin were recorded. Average HbA1c in children under 11 years was 8.3 +/- 1.3% (mean +/- SD) compared with 8.9 +/- 1.8% in those aged 12-18 years. The average insulin dose per kg body weight was almost constant (0.65 U kg(-1) 24 h(-1)) in children aged 2-9 years for both sexes, but there was a sharp increase during the pubertal years, particularly in girls. The increase in BMI of children with diabetes was much faster during adolescence compared to healthy children, especially in females. Sixty per cent of the children (n = 1707) used two daily insulin injections while 37% (n = 1071) used three or more. Of those on two or three injections daily, 37% used pre-mixed insulins, either alone or in combination with short- and intermediate-acting insulin. Pre-adolescent children on pre-mixed insulin showed similar HbA1c levels to those on a combination of short- and long-acting insulins, whereas in adolescents significantly better HbA1c values were achieved with individual combinations. Very young children were treated with a higher proportion of long-acting insulin. Among adolescent boys, lower HbA1c was related to use of more short-acting insulin. This association was not found in girls. We conclude that numerous insulin injection regimens are currently used in paediatric diabetes centres around the world, with an increasing tendency towards intensive diabetes management, particularly in older adolescents. Nevertheless, the goal of near normoglycaemia is achieved in only a few.

Molecular IDDM epidemiology: international studies. WHO DiaMond Molecular Epidemiology Sub-Project Group

The WHO DiaMond Molecular Epidemiology Sub-Project is testing the hypothesis that the geographic differences in IDDM incidence reflect population variation in the frequency of IDDM susceptibility genes (i.e., DQA1 and DQB1 alleles with sequences coding for arginine (R) in position 52 of the DQ alpha-chain, and an amino acid other than aspartic acid (ND) in position 57 of the DQ beta-chain, respectively) using a standardized case-control design. Data from twelve populations which have completed (or have nearly completed) recruitment and HLA molecular analyses are presented. There was an approximate 2-fold increase in the frequencies of DGA1*0301, DQB1*0201 and DQB11*0302 among IDDM cases compared to non-diabetic controls in most populations. Interestingly, DQA*0301 was more common in low versus moderate-high incidence countries. DQB1*0201 and DQB1*0302 were more prevalent in the moderate-high incidence areas. DQA1*R and DQB1*ND were both consistent markers of IDDM risk, with stronger associations in moderate-high versus low incidence areas. In general, individuals homozygous for both DQA1*R and DQB1*ND had the highest genotype-specific IDDM incidence rates, which approximated risk estimates for first degree relatives in several countries. These data revealed considerable variation in the frequencies of DQB1 and DQA1 alleles across countries, which likely contribute to the global patterns of IDDM incidence.

Microchimerism linked to cytotoxic T lymphocyte functional unresponsiveness (clonal anergy) in a tolerant renal transplant recipient

A patient was found to be functionally tolerant of a maternal kidney allograft as evidenced by good graft function 5 years after cessation of all immunosuppressive drug therapy. Despite normal in vitro proliferative and IL-2 responses, patient anti-donor 1 degree MLR cultures yielded little donor-specific CTL activity in either bulk or limiting dilution analysis (LDA) cultures. Using polymerase chain reaction, the patient's PBL and skin were found to contain donor-derived Bw6+ cells. Removal of Bw6+ donor cells from the patient PBL with mAb and immunomagnetic beads before stimulation with donor PBL on day 0 failed to restore donor-specific CTL in either bulk 1 degree MLR or LDA cultures. Restimulation of 1 degree cultures with donor stimulator cells plus exogenous IL-2, however, completely restored anti-donor HLA class I-specific CTL, indicating class I-specific CTL precursors were not clonally deleted. Fresh patient PBL, as well as donor cell-enriched fractions, when added at the initiation of 3 degrees MLR cultures, inhibited the generation of anti-donor CTL, whereas donor cell-depleted fractions did not. The inhibition was cell dose-dependent, was specific for the anti-donor response, and was radioresistant (1200 rad). Thus, the clinical tolerance observed in patients with microchimerism may be due to the presence of veto cells within the circulating donor cell pool.

Detection of Y chromosome sequences in a 45,X/46,XXq--patient by Southern blot analysis of PCR-amplified DNA and fluorescent in situ hybridization (FISH)

In some cases of gonadal dysgenesis, cytogenetic analysis seems to be discordant with the phenotype of the patients. We have applied techniques such as Southern blot analysis and fluorescent in situ hybridization (FISH) to resolve the phenotype/genotype discrepancy in a patient with ambiguous genitalia in whom the peripheral blood karyotype was 45,X. Gonadectomy at age 7 months showed the gonadal tissue to be prepubertal testis on the left side and a streak gonad on the right. The karyotype obtained from the left gonad was 45,X/46,XXq- and that from the right gonad was 45,X. Three different techniques, PCR amplification, FISH, and chromosome painting for X and Y chromosomes, confirmed the presence of Y chromosome sequences. Five different tissues were evaluated. The highest percentage of Y chromosome positive cells were detected in the left gonad, followed by the peripheral blood lymphocytes, skin fibroblasts, and buccal mucosa. No Y chromosomal material could be identified in the right gonad. Since the Xq- chromosome is present in the left gonad (testis), it is likely that the Xq- contains Y chromosomal material. Sophisticated analysis in this patient showed that she has at least 2 cell lines, one of which contains Y chromosomal material. These techniques elucidated the molecular basis of the genital ambiguity for this patient. When Y chromosome sequences are present in patients with Ullrich-Turner syndrome or gonadal dysgenesis, the risk for gonadal malignancy is significantly increased. Hence, molecular diagnostic methods to ascertain for the presence of Y chromosome sequences may expedite the evaluation of patients with ambiguous genitalia.

Non-radioisotopic typing of human leukocyte antigen class II genes on microplates

We describe a new nonradioisotopic method for HLA class II molecular typing performed in 96-well plates of the same size as those used in enzyme-linked immunosorbent assays (ELISA) and radioimmunoassays (RIA). Biotinylated sequence-specific oligonucleotide (SSO) probes are bound to avidin-coated plates. Digoxigenin-labeled PCR-amplified DNA samples are hybridized, washed and detected with a peroxidase conjugated antibody assay. The method was tested by performing a partial HLA DQA1 and DQB1 typing on 69 randomly selected blood samples. The results are completely concordant with a traditional SSO-PCR typing performed on the same samples. This procedure is simple, fast and could be adapted for performance in semi-automated or automated fashion using equipment already available for ELISA and RIA assays.

A cold spot of IDDM incidence in Europe. Macedonia

OBJECTIVE

To determine, for the first time, the incidence of IDDM among children 0-15 yr of age in Macedonia, the south republic of former Yugoslavia, and to compare these rates with those from neighboring countries.

RESEARCH DESIGN AND METHODS

Children < 15 yr of age, with IDDM diagnosed between January 1985 and December 1991, were registered using the criteria established for the WHO Multinational Project for Childhood Diabetes. The primary source of case ascertainment consisted of clinical records from the University Pediatric Clinic in Skopje, the capital of Macedonia. The secondary source consisted of records for insulin supplies from the pharmacy in Skopje and from 15 local hospitals.

RESULTS

During 1985-1991, 112 children < 15 yr of age were diagnosed with IDDM in Macedonia. The completeness of case ascertainment was 96.6%. The age-adjusted IDDM incidence rate was very low, only 2.45/100,000 per yr. No significant sex difference in incidence was observed. The highest incidence rate occurred in the 10- to 15-yr age-group. No temporal trends were observed.

CONCLUSIONS

The incidence of IDDM in Macedonia is the lowest in Europe and among the lowest reported for Caucasian populations. However, the descriptive epidemiology is similar to that for high incidence populations. Further etiological studies are required to evaluate potential reasons for the very low incidence of IDDM in Macedonia.

Detection of Y chromosome sequences in Turner's syndrome by Southern blot analysis of amplified DNA

Only about half of all patients with Turner's syndrome are monosomy 45,X on karyotyping and there are grounds for supposing that cryptic mosaicism for at least part of the Y chromosome may be present in some patients. If so this would be clinically important because of the risk to patients of gonadal neoplasms and virilisation. We have used a very sensitive method to detect Y chromosomal segments in eighteen patients with Turner's syndrome, none of whom had evidence of Y chromosomal material by cytogenetic analysis. In DNA from peripheral blood lymphocytes and/or fibroblasts we looked for specific nucleotide sequences from the sex-determining region of the Y chromosome (SRY gene) and repetitive sequences located at the centromeric region (DYZ3). By polymerase chain amplification (PCR) one patient had a definite positive signal and two patients had faintly positive signals for the SRY gene. Southern blot analysis of PCR material with a SRY-specific probe confirmed that these patients were positive for SRY and revealed another three. No patient was positive for DYZ3, suggesting that only a small portion of Y was present. These results suggest that "pure" 45,X monosomy is less frequent than previously supposed. Long-term follow-up of patients with Y sequences is needed to determine their risk for subsequent gonadal neoplasms and virilisation.

Chimerism and donor-specific nonreactivity 27 to 29 years after kidney allotransplantation

Chimerism was demonstrated with immunocytochemical and/or polymerase chain reaction techniques in kidney allografts and in the native skin, lymph nodes, or blood of 5 of 5 patients who received continuously functioning renal transplants from 1 or 2 haplotype HLA mismatched consanguineous donors (4 parents, 1 aunt) 27-29 years ago. In the 4 cases where the kidney donor still was alive to provide stimulator lymphocytes for testing, these provoked no (n = 2) or modest (n = 2) MLR in contrast to vigorous MLR to third party lymphocytes. In all 4 cases, the donor cells failed to generate in vitro cytotoxic effector cells (cell-mediated lymphocytotoxicity). These findings are in accord with the hypothesis that cell migration, repopulation, and chimerism are seminal events that define graft acceptance and ultimately can lead to acquired donor-specific nonresponsiveness (tolerance).

Chimerism after liver transplantation for type IV glycogen storage disease and type 1 Gaucher's disease

BACKGROUND

Liver transplantation for type IV glycogen storage disease (branching-enzyme deficiency) results in the resorption of extrahepatic deposits of amylopectin, but the mechanism of resorption is not known.

METHODS

We studied two patients with type IV glycogen storage disease 37 and 91 months after liver transplantation and a third patient with lysosomal glucocerebrosidase deficiency (type 1 Gaucher's disease), in whom tissue glucocerebroside deposition had decreased 26 months after liver replacement, to determine whether the migration of cells from the allograft (microchimerism) could explain the improved metabolism of enzyme-deficient tissues in the recipient. Samples of blood and biopsy specimens of the skin, lymph nodes, heart, bone marrow, or intestine were examined immunocytochemically with the use of donor-specific monoclonal anti-HLA antibodies and the polymerase chain reaction, with preliminary amplification specific to donor alleles of the gene for the beta chain of HLA-DR molecules, followed by hybridization with allele-specific oligonucleotide probes.

RESULTS

Histopathological examination revealed that the cardiac deposits of amylopectin in the patients with glycogen storage disease and the lymph-node deposits of glucocerebroside in the patient with Gaucher's disease were dramatically reduced after transplantation. Immunocytochemical analysis showed cells containing the HLA phenotypes of the donor in the heart and skin of the patients with glycogen storage disease and in the lymph nodes, but not the skin, of the patient with Gaucher's disease. Polymerase-chain-reaction analysis demonstrated donor HLA-DR DNA in the heart of both patients with glycogen storage disease, in the skin of one of them, and in the skin, intestine, blood, and bone marrow of the patient with Gaucher's disease.

CONCLUSIONS

Systemic microchimerism occurs after liver allotransplantation and can ameliorate pancellular enzyme deficiencies.

Systemic chimerism in human female recipients of male livers

We have previously reported data from clinical and laboratory animal observations which suggest that organ tolerance after transplantation depends on a state of balanced lymphodendritic cell chimerism between the host and donor graft. We have sought further evidence to support this hypothesis by investigating HLA-mismatched liver allograft recipients. 9 of 9 female recipients of livers from male donors had chimerism in their allografts and extrahepatic tissues, according to in-situ hybridisation and molecular techniques 10 to 19 years posttransplantation. In 8 women with good graft function, evidence of the Y chromosome was found in the blood (6/8), skin (8/8), and lymph nodes (7/8). A ninth patient whose transplant failed after 12 years from recurrent chronic viral hepatitis had chimerism in her lymph nodes, skin, jejunum, and aorta at the time of retransplantation. Although cell migration is thought to take place after all types of transplantation, the large population of migratory cells in, and the extent of their seeding from, hepatic grafts may explain the privileged tolerogenicity of the liver compared with other organs.

Autoimmunity and genetics contribute to the risk of insulin-dependent diabetes mellitus in families: islet cell antibodies and HLA DQ heterodimers

The risk for insulin-dependent diabetes mellitus (IDDM) associated with genetic susceptibility markers at the human leukocyte antigen (HLA) DQA1 and DQB1 loci was evaluated among individuals with and those without islet cell antibodies. A total of 108 antibody-positive parents and siblings of IDDM patients from the Pittsburgh registry were identified among 1,592 who were screened. HLA-DQ molecular typing was performed on 79 of these individuals and on 78 antibody-negative relatives. There were similar proportions of homozygotes for both of the diabetogenic alleles DQA1 arginine-52 (R/R) and DQB1 non-aspartate-57 (nD/nD) among the antibody-positive and antibody-negative relatives (19.0 and 15.4%, respectively). However, subsequent development of IDDM was restricted to individuals who were both antibody positive and carried the potential to make at least one diabetogenic DQ heterodimer. A dose-response effect was observed among the antibody-positive relatives, in which two of 18 capable of generating one diabetogenic heterodimer and six of 29 generating two heterodimers became insulin requiring. Nine of 15 who were homozygous for both R/R and nD/nD, coding exclusively for diabetogenic variants, became diabetic over the course of the follow-up. With a multivariate model, the relative risk for IDDM among those with islet cell antibodies who were also R/R and nD/nD was estimated to be 229.3 compared with those lacking both, after age and sex were controlled for. The data suggest that while autoimmunity, indicated by the presence of cytoplasmic islet cell antibodies may be relatively common, it progresses only in those with variant HLA-DQ molecules.

Translocation between chromosomes 1 and 9 in childhood acute lymphoblastic leukemia

A case of a non-T, non-B acute lymphoblastic leukemia with a translocation between chromosomes #1 and #9 is described. The breakpoints in these chromosomes were determined to be at bands 1q23 and 9p22, respectively. The breakpoint in chromosome #1 was at the same site as that in a subgroup of acute lymphoblastic leukemia with t(1;19), and the breakpoint in #9 was the same as that in t(9;11)(p22;q23) in acute monoblastic leukemia. We discuss the possible association between these chromosome bands (1q23, 9p22, 11q23, and 19p13) and the morphologic features of the leukemic cells. The breakpoint in chromosome band 1q23 may be specifically associated with acute lymphoblastic leukemia.

Secondary acute myeloblastic leukemia with a Ph translocation in a treated Wegener's granulomatosis

Ph-positive acute myeloblastic leukemia (AML) developing in a treated case of Wegener's granulomatosis is reported. The patient was a 70-year-old white male who received cyclophosphamide (150 mg/day) starting in July 1978; in May 1984 the patient was diagnosed as having AML, following a diagnosis of myelodysplastic syndrome lasting 3 months. Cytogenetic study of bone marrow cells at the diagnosis of the myelodysplastic syndrome revealed a standard Ph translocation in addition to numerical chromosome changes [i.e., 45,XY, -5, -7, -8, +19, +mar/45,XY, -5, -7, -8, +19, +mar,t(9;22)(q34;q11]). The events in this case suggest a strong possibility of the Ph-positive AML being a secondary disease related to prior cyclophosphamide therapy.

Translocation 4;11 acute leukemia: three case reports and review of the literature

Three children with acute leukemia and t(4;11)(q21;q23) are presented. Two of the cases showed very unusual karyotypic findings and long survival for the type of leukemia. In case B.T., the original karyotype change observed was t(4;11), with other changes (+4q-,+11q+,+6,+10) appearing during the last stages of the disease. In case R.B., the translocation was accompanied by many numerical and morphological chromosome changes, with a near-tetraploid chromosome number. In both of the above cases, remission was associated with a normal marrow karyotype. In case D.C., only the t(4;11) was observed. The number of cases with t(4;11) and acute leukemia published so far is 36, including the three cases presented by us. As this disease is usually characterized by a relatively short survival, the possible reasons for the remarkably long survival in two of our patients are discussed in relation to the rather unusual cytogenetic findings.