Neuropathy in paediatric type 1 diabetes mellitus - clinical characterization and analysis of risk factors in the diabetes prospective follow-up registry DPV (Diabetes-Patienten-Verlaufsdokumentation)-registry

OBJECTIVES

Data on the prevalence, clinical features and risk factors associated with paediatric diabetic neuropathy (DN) are scarce.

METHODS

We retrospectively analysed data from the DPV registry, including patients under 20 years of age, treated for type 1 diabetes mellitus (T1D) between 2005 and 2021. Patients with non-diabetic neuropathy were excluded. Data came from centres in Austria, Germany, Luxembourg and Switzerland.

RESULTS

1,121 of the 84,390 patients included had been diagnosed with DN. Univariate analysis showed patients with DN to be older and predominantly female, with a longer duration of T1D, higher insulin dosages per kg and day, lower rates of insulin pump therapy, higher postprandial glucose-, higher HbA_1c-and higher cholesterol levels, and higher diastolic and systolic blood pressure values. There was also a larger proportion of smokers and higher prevalence of diabetic retinopathy. Median duration of diabetes at diagnosis of DN was 8.3 years. Multivariable analysis, adjusted for demographics revealed an increased risk for DN among female patients and those who were older, underweight (BMI-SDS), smoked cigarettes or had a longer duration of T1D or higher levels of HbA_1c and postprandial blood glucose. The presence of retinopathy and higher cholesterol levels were also linked to increased risk while not-using insulin pump therapy was not.

CONCLUSIONS

DN can develop after just a short duration of T1D. Prevention may be achieved by a lowering of HbA_1c-and postprandial glucose levels through improved glycaemic control. This warrants further investigation. The slight female predominance suggests further hormonal and genetic etiological factors.

Incidence and presentation of new-onset type 1 diabetes in children and adolescents from Germany during the COVID-19 pandemic 2020 and 2021: Current data from the DPV Registry

AIMS

To determine whether the incidence of type 1 diabetes mellitus (T1D), autoantibody-negative diabetes, and diabetic ketoacidosis (DKA) at diabetes onset in 2020 and 2021 changed when compared to long-standing trends.

METHODS

Our study is based on diabetes manifestation data of the 0.5-<18-year-old children/adolescents from the German multicenter Diabetes Prospective Follow-up Registry. Based on long-term pre-pandemic trends from 2011 to 2019, we estimated adjusted incidence rate ratios (IRR) for T1D and DKA, and prevalence rate ratios (PRR) regarding autoantibody status with 95 % confidence intervals (CI) for the years 2020 and 2021 (observed versus predicted rates), using multivariable negative binomial or beta-binomial regression, respectively.

RESULTS

We analyzed data of 30,840 children and adolescents with new-onset T1D. The observed incidences were significantly higher than the predicted incidences (IRR₂₀₂₀ 1.13 [1.08-1.19]; IRR₂₀₂₁ 1.20 [1.15-1.26]). The prevalence of autoantibody-negative diabetes did not change (PRR₂₀₂₀ 0.91 [0.75-1.10]; PRR₂₀₂₁ 1.03 [0.86-1.24]). The incidence of DKA during the pandemic was higher than predicted (IRR₂₀₂₀ 1.34 [1.23-1.46]; IRR₂₀₂₁ 1.37 [1.26-1.49]).

CONCLUSIONS

An increase in the incidences of T1D and DKA, but not of autoantibody-negative diabetes was observed during both pandemic years. Further monitoring and efforts for DKA prevention at onset are necessary.

Sex chromosome DSD individuals with mosaic 45,X0 and aberrant Y chromosomes in 46,XY cells: distinct gender phenotypes and germ cell tumour risks§

"Differences of Sexual Development (DSD)," individuals with rearranged Y chromosome breaks in their 46,XY cells are reported with male and female gender phenotypes and differences in germ cell tumour (GCT) risk. This raised the question of whether male or female gender and GCT risk depends on the site of the break and/or rearrangement of the individual´s Y chromosome. In this paper, we report molecular mapping of the breakpoint on the aberrant Y chromosome of 22 DSD individuals with a 45,X/46,XY karyotype reared with a different gender. Their Y chromosome breaks are found at different sites on the long and short Y arms. Our data indicate that gender rearing is, neither dependent on the site of Y breakage, nor on the amount of 45,X0 cells in the individuals' leukocytes. Most prominent are secondary rearrangements of the Y chromosome breaks forming di-centric Y-structures ("dic-Y"). Duplications of the short Y arm and the proximal part of the long Y arm are the results. A putative GCT risk has been analysed with immunohistochemical experiments on some dysgenetic gonadal tissue sections. With specific antibodies for OCT3/4 expression, we marked the pluripotent germ cell fraction being potential tumour precursor cells. With specific antibodies for DDX3Y, TSPY, and UTY we analyzed their putative Gonadoblastoma Y (GBY) tumour susceptibility function in the same specimen. We conclude GBY expression is only diagnostic for GCT development in the aberrant germ cells of these DSD individuals when strong OCT3/4 expression has marked their pluripotency.

Gonadoblastoma Y locus genes expressed in germ cells of individuals with dysgenetic gonads and a Y chromosome in their karyotypes include DDX3Y and TSPY

STUDY QUESTION

Which Y genes mapped to the 'Gonadoblastoma Y (GBY)' locus on human Y chromosome are expressed in germ cells of individuals with some Differences of Sexual Development (DSD) and a Y chromosome in their karyotype (DSD-XY groups)?

SUMMARY ANSWER

The GBY candidate genes DDX3Y and TSPY are expressed in the germ cells of DSD-XY patients from distinct etiologies: patients with mixed gonadal dysgenesis (MGD) and sex chromosome mosaics (45,X0/46,XY; 46,XX/46,XY); patients with complete androgen insensitivity (CAIS), patients with complete gonadal dysgenesis (CGD; e.g. Swyer syndrome).

WHAT IS KNOWN ALREADY

A GBY locus was proposed to be present on the human Y chromosome because only DSD patients with a Y chromosome in their karyotype have a high-although variable-risk (up to 55%) for germ cell tumour development. GBY was mapped to the proximal part of the short and long Y arm. TSPY located in the proximal part of the short Y arm (Yp11.1) was found to be a strong GBY candidate gene. It is expressed in the germ cells of DSD-XY patients with distinct etiologies but also in foetal and pre-meiotic male spermatogonia. However, the GBY region extends to proximal Yq11 and therefore includes probably more than one candidate gene.

STUDY DESIGN, SIZE, DURATION

Protein expression of the putative GBY candidate gene in proximal Yq11, DDX3Y, is compared with that of TSPY in serial gonadal tissue sections of 40 DSD-XY individuals from the three DSD patient groups (MGD, Complete Androgen Insensitivity Syndrome [CAIS], CGD) with and without displaying malignancy. Expression of OCT3/4 in the same tissue samples marks the rate of pluripotent germ cells.

PARTICIPANTS/MATERIALS, SETTING, METHOD

A total of 145 DSD individuals were analysed for the Y chromosome to select the DSD-XY subgroup. PCR multiplex assays with Y gene specific marker set score for putative microdeletions in GBY Locus. Immunohistochemical experiments with specific antisera mark expression of the GBY candidate proteins, DDX3Y, TSPY, in serial sections of the gonadal tissue samples; OCT3/4 expression analyses in parallel reveal the pluripotent germ cell fraction.

MAIN RESULTS AND THE ROLE OF CHANCE

Similar DDX3Y and TSPY protein expression patterns were found in the germ cells of DSD-XY patients from each subgroup, independent of age. In CAIS patients OCT3/4 expression was often found only in a fraction of these germ cells. This suggest that GBY candidate proteins are also expressed in the non-malignant germ cells of DSD-XY individuals like in male spermatogonia.

LIMITATIONS, REASONS FOR CAUTION

Variation of the expression profiles of GBY candidate genes in the germ cells of some DSD-XY individuals suggests distinct transcriptional and translational control mechanisms which are functioning during expression of these Y genes in the DSD-XY germ cells. Their proposed GBY tumour susceptibility function to transform these germ cells to pre-malignant GB/Germ Cell Neoplasia in Situ (GB/GCNIS) cells seems therefore to be limited and depending on their state of pluripotency.

WIDER IMPLICATIONS OF THE FINDINGS

These experimental findings are of general importance for each individual identified in the clinic with DSD and a Y chromosome in the karyotype. To judge their risk of germ cell tumour development, OCT3/4 expression analyses on their gonadal tissue section is mandatory to reveal the fraction of germ cells still being pluripotent. Comparative expression analysis of the GBY candidate genes can be helpful to reveal the fraction of germ cells with genetically still activated Y chromosomes contributing to further development of malignancy if at high expression level.

STUDY FUNDING/COMPETING INTEREST(S)

This research project was supported by a grant (01GM0627) from the BMBF (Bundesministerium für Bildung und Forschung), Germany to P.H.V. and B.B. The authors have no competing interests.

Guanine nucleotide-binding protein α subunit hypofunction in children with short stature and disproportionate shortening of the 4th and 5th metacarpals

BACKGROUND

GNAS encodes the α subunit of the stimulatory G protein (Gsα). Maternal inherited Gsα mutations cause pseudohypoparathyroidism type Ia (PHP-Ia), associated with shortening of the 4th and 5th metacarpals.

AIMS

Here we investigated the Gsα pathway in short patients with distinct shortening of the 4th and 5th metacarpals.

METHODS

In 571 children with short stature and 4 patients with PHP-Ia metacarpal bone lengths were measured. In identified patients we analysed the Gsα protein function in platelets, performed GNAS sequencing, and epigenetic analysis of four significant differentially methylated regions.

RESULTS

In 51 patients (8.9%) shortening of the 4th and 5th metacarpals was more pronounced than their height deficit. No GNAS coding mutations were identified in 20 analysed patients, except in 2 PHP-Ia patients. Gsα activity was reduced in all PHP-Ia patients and in 25% of the analysed patients. No significant methylation changes were identified.

CONCLUSIONS

Our findings suggest that patients with short stature and distinct metacarpal bone shortening could be part of the wide variety of PHP/PPHP, therefore it was worthwhile analysing the Gsα protein function and GNAS gene in these patients in order to further elucidate the phenotype and genotype of Gsα dysfunction.

Analyses of Gonadoblastoma Y (GBY)-locus and of Y centromere in Turner syndrome patients

BACKGROUND

Mosaicism with cytogenetically visible Y chromosome is found in 5-6% of Turner Syndrome (TS) patients. Additionally, occult Y-chromosome derived material is increasingly found in patients with monosomy X when using more sensitive molecular techniques. These TS patients are at risk of developing gonadoblastomas when the Y genes presumed to be involved in gonadoblastoma development (Gonadoblastoma-Y-locus; GBY) are present.

AIM

To find occult Y-chromosome material in TS patients and to correlate the patient's phenotype to Y-chromosome material.

METHODS

We studied 60 TS-patients for presence of the Y chromosome with focus on the Gonadoblastoma Y-locus and its extension in Yp and Yq using sensitive Y centromere and Y gene deletion PCR assays. In addition, we evaluated their individual clinical and auxological characteristics.

RESULTS

We identified presence of the GBY-locus in 7 patients (11.7%) including 4 patients without evidence for a Y chromosome in their preceding standard karyotype analyses. Clinical and auxological characteristics were similar in GBY-positive and GBY-negative patients.

CONCLUSIONS

Presence of the GBY locus in Turner patients with no indication of the Y chromosome in standard cytogenetic chromosome analysis can be revealed by sensitive molecular PCR assays screening for presence of the Y centromere and the GBY-candidate-genes in proximal Yp11 and Yq11, respectively.

Increase of serum leptin after short-term pulsatile GnRH administration in children with delayed puberty

OBJECTIVE

Leptin is known to play an important role in pubertal development in humans, probably acting as one permissive factor for the onset of puberty. Leptin serum concentrations change during pubertal development and an initial increase before the onset of puberty has been reported. The underlying mechanism for this increase in leptin levels is unknown. We hypothesized that the pulsatile release of GnRH stimulates leptin metabolism. In this study, the effect of short-term pulsatile GnRH administration on leptin levels in children with delayed onset of puberty was investigated.

METHODS

Nineteen children (15 males and four females, mean age 15.5 years, range 13.1-20.5 years), who underwent evaluation for delayed sexual maturation, were included in the study. Sixteen subjects received 36 h of pulsatile intravenous GnRH, using an infusion pump that released 5 microg GnRH every 90 min. Serum concentrations of LH, FSH, testosterone, estradiol and leptin were analysed before and up to 36 h after GnRH administration. Eight patients received a single dose GnRH-agonist stimulation test (buserelin acetate test, 10 microg/kg body weight) with a 24-h follow-up (five patients underwent both tests).

RESULTS

Mean (+/-s.e.m.) serum leptin increased significantly (P<0.01) after 36 h of pulsatile GnRH administration (7.26+/-1.35 vs 9.75+/-1.76 ng/ml). In contrast, no increase in leptin concentrations was observed after administration of a single dose of buserelin.

CONCLUSIONS

These findings suggested that the increase in serum leptin at the onset of puberty is triggered by the pulsatile release of GnRH.

Short stature in children with an apparently normal male phenotype can be caused by 45,X/46,XY mosaicism and is susceptible to growth hormone treatment

Girls with unexplained short stature are routinely screened for the presence of Ullrich-Turner syndrome by clinical examination, laboratory tests, and karyotyping. In this study, we performed chromosomal analysis in boys to explore the role of 45,X/46,XY mosaicism for short stature in males. Short-term effects of growth hormone treatment in male 45,X/46,XY individuals were compared retrospectively to those in female patients. We report six boys with a normal-appearing male phenotype and 45,X/46,XY mosaicism, four of whom were diagnosed postnatally because of short stature. Two boys were diagnosed prenatally by amniocentesis. Five boys were short and were treated with growth hormone (0.04-0.05 mg/kg per day) in analogy to girls with Ullrich-Turner syndrome and gonadal dysgenesis. With the exception of one patient in whom treatment was initiated only at the age of 14.6 years, the male patients with 45,X/46,XY mosaicism responded to short-term growth hormone treatment similarly to females with an increasing height SDS.

CONCLUSION

45,X/46,XY mosaicism remains undetected in some short boys because this group is not routinely karyotyped. We recommend chromosomal analysis of boys with otherwise unexplained short stature who are short for their families. Growth hormone treatment should be offered to short boys with 45,X/46,XY mosaicism and a predicted adult height below the mid-parental range within clinical trials.

Lipid-laden macrophages in bronchoalveolar lavage fluid as a marker for pulmonary aspiration

An increased lipid content in alveolar macrophages of bronchoalveolar lavage (BAL) fluid is thought to be a useful indicator for recurrent pulmonary aspiration. To assess whether pulmonary diseases unrelated to aspiration can raise the lipid content in alveolar macrophages, we evaluated Oil-Red-O-stained smears of BAL fluid in 18 children aged 3-15 years undergoing elective surgery for nonpulmonary illnesses under general anesthesia and in 18 children aged 1-16 years who had pulmonary diseases without clinical evidence of aspiration (pneumonia, exogenous allergic alveolitis, or cystic fibrosis). A semiquantitative lipid-laden macrophage (LLM) index was determined for each patient. LLM indices in children without pulmonary disease were higher than those published for healthy adults. In children with pulmonary diseases but without evidence of aspiration, a significantly higher LLM index was observed compared to controls. The LLM indices of children with pulmonary diseases were similar to those published by other authors for children with pulmonary aspiration. We conclude that an elevated LLM index in alveolar macrophages of BAL can be found in a variety of pulmonary diseases in which there is no clinical evidence of aspiration and is therefore unlikely to be a specific parameter for silent pulmonary aspiration.

Tuberculoma of the pons

A case of a pontine tuberculoma in a 12-year-old male from Somalia is presented. Cranial magnetic resonance imaging, performed in Abu Dhabi 1 month before admission in Germany revealed a tumorous lesion in the pons with surrounding edema; a presumptive diagnosis of a pontine glioma was made. Chest radiograph disclosed a pulmonary infiltrate with cavitation, as well as hilar and left mediastinal lymphadenopathy, suggestive of active tuberculosis. Tuberculostatic therapy led to an improvement of the patient's clinical status and a significant reduction in the size of the pontine tuberculoma. Intracranial tuberculomas rarely are seen in industrialized countries. They should, however, be considered as an important part of the differential diagnosis of intracranial space-occupying lesions. In most cases, as in this patient, conservative therapy provides good or excellent results.

[Mastoiditis in childhood]

BACKGROUND

Despite new antibiotics mastoiditis in children still is a serious infection confronting the pediatrician and otolaryngologist with diagnostic and therapeutic problems.

PATIENTS AND METHODS

In a retrospective study we reviewed the charts of 48 children who had a mastoidectomy from 1990 to 1995 in the Department of Oto-Rhino-Laryngology at the University of Essen.

RESULTS

60% of the patients presented with a retroauricular swelling, and a pathologic tympanic membrane was found in 89%. The erythrocyte sedimentation rate as the most valuable laboratory parameter was increased in 95% of cases. Larger osteodestructive lesions as a complication of mastoiditis could be predicted in three of ten cases by plain x-ray of the temporal bone. The most common bacteria to be isolated were Staphylococcus aureus, Streptococcus pneumoniae and Pseudomonas aeruginosa.

CONCLUSION

Because of potential endocranial complications (10% in our patients) as well as difficult radiologic diagnosis of osteodestructive lesions by plain x-ray, we advocate mastoidectomy instead of a mere pharmacological therapy in the treatment of mastoiditis.