R. Coutant

Identification and management of poor response to growth‐promoting therapy in children with short stature

Growth hormone (GH) is widely prescribed for children with short stature across a range of growth disorders. Recombinant human (rh) insulin‐like growth factor‐1 (rhIGF‐1) therapy is approved for severe primary IGF‐I deficiency – a state of severe GH resistance. Evidence is increasing for an unacceptably high rate of poor or unsatisfactory response to growth‐promoting therapy (i.e. not leading to significant catch up growth) in terms of change in height standard deviation score (SDS) and height velocity (HV) in many approved indications. Consequently, there is a need to define poor response and to prevent or correct it by optimizing treatment regimens within accepted guidelines. Recognition of a poor response is an indication for action by the treating physician, either to modify the therapy or to review the primary diagnosis leading either to discontinuation or change of therapy. This review discusses the optimal investigation of the child who is a candidate for GH or IGF‐1 therapy so that a diagnosis‐based choice of therapy and dosage can be made. The relevant parameters in the evaluation of growth response are described together with the definitions of poor response. Prevention of poor response is addressed by discussion of strategy for first‐year management with GH and IGF‐1. Adherence to therapy is reviewed as is the recommended action following the identification of the poorly responding patient. The awareness, recognition and management of poor response to growth‐promoting therapy will lead to better patient care, greater cost‐effectiveness and increased opportunities for clinical benefit.

DIAGNOSIS OF ENDOCRINE DISEASE: Limitations of the IGF1 generation test in children with short stature

The IGF1 generation test (IGFGT) is often used during the assessment of suspected GH insensitivity (GHI). We report the results of a survey undertaken in 2010 to determine the use of IGFGT amongst members of the European Society for Paediatric Endocrinology to evaluate suspected GHI. The literature surrounding the usefulness and limitations of IGFGT are reviewed, and recommendations provided for its use. Of 112 paediatric endocrinologists from 30 countries who responded to the survey, 91 (81%) reported that they had used the IGFGT in the previous 2 years; >10 IGFGT protocols were used. The IGFGT impacted treatment decisions for 97% of the respondents and was a prerequisite for recombinant human IGF1 treatment for 45% of respondents. From a literature review, sensitivity of the IGFGT was evaluated as 77-91% in molecularly proven cases of GHI; specificity was ≤97%, depending on the protocol. The positive predictive value of the IGFGT is likely to be low, as the frequency of normality is predictably higher than that of abnormality in GH signalling. Given the limitations of the IGFGT in the most severe cases of GHI syndrome (GHIS), the ability of the IGFGT to detect less severe GHIS is doubtful. In a pragmatic approach, the IGFGT may not be useful for the diagnosis of GHIS.

Should 45,X/46,XY boys with no or mild anomaly of external genitalia be investigated and followed up?

OBJECTIVE Few studies of patients with a 45,X/46,XY mosaicism have considered those with normal male phenotype. The purpose of this study was to evaluate the clinical outcome of 45,X/46,XY boys born with normal or minor abnormalities of external genitalia, notably in terms of growth and pubertal development. METHODS Retrospective longitudinal study of 40 patients followed between 1982 and 2017 in France. RESULTS Twenty patients had a prenatal diagnosis, whereas 20 patients had a postnatal diagnosis, mainly for short stature. Most patients had stunted growth, with abnormal growth spurt during puberty and a mean adult height of 158 ± 7.6 cm, i.e. -2.3 DS with correction for target height. Seventy percent of patients presented Turner-like syndrome features including cardiac (6/23 patients investigated) and renal malformations (3/19 patients investigated). Twenty-two patients had minor abnormalities of external genitalia. One patient developed a testicular embryonic carcinoma, suggesting evidence of partial gonadal dysgenesis. Moreover, puberty occurred spontaneously in 93% of patients but 71% (n = 5) of those evaluated at the end of puberty presented signs of declined Sertoli cell function (low inhibin B levels and increased FSH levels). CONCLUSION This study emphasizes the need to identify and follow-up 45,X/46,XY patients born with normal male phenotype until adulthood, as they present similar prognosis than those born with severe genital anomalies. Currently, most patients are diagnosed in adulthood with azoospermia, consistent with our observations of decreased testicular function at the end of puberty. Early management of these patients may lead to fertility preservation strategies.

Patients’ perceptions on the usability of the SurePal™ self-injection device for Omnitrope®: a questionnaire-based observational study conducted in paediatric patients in France

Background: A questionnaire-based survey was conducted to evaluate attitudes towards a reusable self-injection system, SurePal™, among paediatric patients with growth disturbances who were prescribed treatment with somatropin (Omnitrope®) as part of routine clinical practice. Methods: This cross-sectional survey was incorporated into the multinational, multi-centre, noninterventional PAtients TReated with Omnitrope® (PATRO) Children study. Questions were mainly focused on five areas: the attractiveness of SurePal™; training received; use of the device; opinion of the low-drug wastage system; experience compared with previous devices used (among pretreated patients). Results: Final results from participants in France are reported. Completed questionnaires were returned by 409 participants. Most patients (55%) were male and 89% were recombinant human growth hormone (rhGH)-treatment naïve. Around 57% of children completed the questionnaire by themselves, while 43% had help from a family member/other person. The mean (standard deviation) age of all participants was 11.3 (3.6) years, and most patients were aged 10–12 years (n = 126) or 13–15 years (n = 117). Overall, 86% of patients reported that preparing SurePal™ for injection was easy/very easy. Similarly, 83% reported that performing injections with SurePal™ was easy/very easy. The attractiveness of SurePal™ was rated as good/excellent by the majority (85%) of patients; this proportion was similarly high (> 80%) across all age groups. The dose-memory function was rated as helpful/very helpful by 54% of patients. Of the 174 patients who reported using the low drug-waste feature, 90% found it to be helpful/very helpful. Among the 24 pretreated patients, 17 reported that SurePal™ was better/much better than their previous device. Conclusions: This questionnaire-based survey conducted in a large cohort of paediatric patients with growth disturbances from France confirms the ease of use of SurePal™ to support daily administration of Omnitrope® across all age groups. The demonstrated acceptability of the device may help to improve patient adherence to long-term daily treatment with rhGH.