Treatment of Short Stature in Aggrecan Deficient Patients with Recombinant Human Growth Hormone: One-Year Response

Context Patients with aggrecan (ACAN) deficiency present with dominantly inherited short stature, often with advanced skeletal maturation and premature growth cessation. There is a paucity of information on the effects of growth-promoting interventions. Objective The aim of this study was to evaluate the efficacy and safety of recombinant human growth hormone (rhGH) therapy on linear growth in children with ACAN deficiency. Design and Setting Open-label, single-arm, prospective study at Cincinnati Children’s Hospital Medical Center. Patients Ten treatment-naïve patients were recruited. Inclusion criteria were: a confirmed heterozygous mutation in ACAN, age ≥ 2 years, pre-pubertal, bone age (BA) ≥ chronological age (CA), and normal IGF-I concentration. Intervention Treatment with rhGH (50 mcg/kg/day) over one year. Main Outcome Measure(s) Main outcomes measured were height velocity (HV) and change in (Δ) height SD (HtSDS). Results Ten patients (six females) were enrolled with median CA of 5.6 yrs (range 2.4 to 9.7). Baseline median HtSDS was -2.5 (range -4.3 to -1.1). Median baseline BA was 6.9 yrs (range 2.5 to 10.0), with median BA/CA of 1.2 (range 0.9 to 1.5). Median pre-treatment HV was 5.2 cm/y (range 3.8 to 7.1), increased to 8.3 cm/y (range 7.3 to 11.2) after one year of therapy (p=0.004). Median ΔHtSDS after one year was +0.62 (range +0.35 to +1.39) (p=0.002). Skeletal maturation did not advance inappropriately (median Δ BA/CA -0.1, p=0.09). No adverse events related to rhGH were observed. Conclusion Treatment with rhGH improved linear growth in a cohort of patients with short stature due to ACAN deficiency.

Amino acid substitutions in human growth hormone affect coiled-coil content and receptor binding

The interaction between human Growth Hormone (hGH) and hGH Receptor (hGHR) has great relevance to human diseases such as acromegaly and cancer. HGH has been extensively engineered by other workers to improve binding and other properties. We used a computational screen to select substitutions at single hGH positions within the hGHR-binding site. We find that, while many successfully slow down dissociation of the hGH-hGHR complex once bound, they also slow down the association of hGH to hGHR. We are particularly interested in E174 which belongs to the hGH zinc-binding triad, and which spans coiled-coil helices and obeys the coiled-coil heptad pattern. Surprisingly, substituting E174 with A leads to substantial increase in an experimental measure of coiled-coil content. E174A is known to increase affinity of hGH against hGHR; here we show that this is simply because the off-rate is slowed down more than the on-rate, in line with what has been found for other affinity-improving mutations. For E174Y (and mutations at other sites) the slowdown in on-rate was greater, leading to decreased affinity. The results point to a link between coiled-coiling, zinc binding, and hGHR-binding affinity in hGH, and also suggest rules for choosing affinity-increasing substitutions.

Clinical Characteristics and Long-Term Recombinant Human Growth Hormone Treatment of 18q- Syndrome: A Case Report and Literature Review

Background18q- syndrome is a rare chromosomal disease caused by the deletion of the long arm of chromosome 18. Some cases with 18q- syndrome can be combined with growth hormone deficiency (GHD), but data on the efficacy of recombinant human growth hormone (rhGH) treatment in 18q- syndrome are limited.MethodsHere, we report one case of 18q- syndrome successfully treated with long-term rhGH supplement. Previously reported cases in the literature are also reviewed to investigate the karyotype–phenotype relationship and their therapeutic response to rhGH.ResultsA 7.9-year-old girl was referred for evaluation for short stature. Physical exam revealed proportionally short stature with a height of 111.10 cm (−3.02 SD score (SDS)), low-set ears, a high-arched palate, a small jaw, webbed neck, widely spaced nipples, long and tapering fingers, and cubitus valgus. Thyroid function test indicated subclinical hypothyroidism. The peak value of growth hormone was 10.26 ng/ml in the levodopa provocation test. Insulin-like growth factor 1 (IGF-1) was 126 ng/ml (57–316 ng/ml). Other laboratory investigations, including complete blood cell count, liver and kidney function, gonadal function, serum adrenocorticotropin levels, and serum cortisol levels, were all within normal ranges. Karyotype analysis showed 46, XX, del (18) (q21). L-Thyroxine replacement and rhGH treatment were initiated and maintained in the following 7 years. At the age of 14.8, her height has reached 159.5 cm with a height SDS increase of 2.82 SDS (from −3.02 SDS to −0.20 SDS). No significant side effects were found during the treatment. The literature review indicated the average rhGH treatment duration of 16 patients was 5.9 ± 3.3 years, and the average height SDS significantly increased from −3.12 ± 0.94 SDS to −1.38 ± 1.29 SDS after the rhGH treatment (p < 0.0001).ConclusionThe main clinical manifestations of 18q- syndrome include characteristic appearance, intellectual disability, and abnormal genital development. The literature review suggested a significant height benefit for short stature with 18q- syndrome from long-term rhGH treatment.

Recombinant Human Growth Hormone Inhibits Lipotoxicity, Oxidative Stress, and Apoptosis in a Mouse Model of Diabetic Cardiomyopathy

Recombinant human growth hormone (rhGH), widely used in clinical studies, exerts protective effects against cardiac damage. Here, we investigated the effects and mechanisms underlying the effects of rhGH on cardiac functions in db/db mice. C57BL/6J and db/db mice were subjected to rhGH treatment. Metabolic parameters, cardiac function and morphology, oxidative stress, lipid metabolism, and apoptosis were evaluated 16 weeks after rhGH treatment. Although rhGH did not significantly affect fasting blood glucose levels in db/db mice, it protected against diabetic cardiomyopathy, by improving cardiac function and reducing oxidative stress in the heart. In addition, rhGH treatment exhibited anti-apoptotic effects in the heart of db/db mice. The rhGH treatment, besides inhibiting oxidative stress and apoptosis, ameliorated cardiac dysfunction by inhibiting lipotoxicity in mice with type 2 diabetes. These findings suggest that rhGH is a promising therapeutic agent for diabetic cardiomyopathy.

Comparative study of human growth hormone measurements: impact on clinical interpretation

Objectives Human growth hormone (hGH) provocation test is an essential tool to assess growth hormone deficiency (GHD) in children and young adults. It is important to have a robust method to determine the hGH peak of stimulation. This work aimed to compare three common automated immunoassays for hGH quantification and to ascertain whether there are still result-related differences which can impact clinical decision. Methods We analyzed the GH provocation test for 39 young subjects from pediatric department of Montpellier hospital, admitted for suspicion of growth hormone deficiency. The full range of measurements as well as the peak level of serum GH were compared using three automated immunoassays on three different immunoanalyzers: IDS-hGH on iSYS, LIAISON-hGH on Liaison XL and Elecsys ROCHE-hGH, on COBAS 8000. Results A good correlation was obtained between methods for all measurements (r 2>0.99) by using Passing–Bablok regression analysis. Bland–Altman analysis showed the best agreement between IDS-hGH and LIAISON-hGH systems (bias=−14.5%) compared to Elecsys ROCHE-hGH (bias=28.3%). When considering stratification of the study population and a unique cutoff, there were some discrepancies in interpretation of the results especially concerning the more recent Elecsys ROCHE-hGH assay. Nevertheless, when the adequate cutoff for each method was taken into account results were well correlated for all systems. Conclusions A cutoff for Elecsys Roche-hGH method was established to better explain the results. Clinician must be aware of the use of assay-specific cutoff to correctly integrate the results of GH tests in the GHD diagnosis.

Reduced Effectiveness and Comparable Safety in Biweekly vs. Weekly PEGylated Recombinant Human Growth Hormone for Children With Growth Hormone Deficiency: A Phase IV Non-Inferiority Threshold Targeted Trial

ContextLong-acting recombinant human growth hormone (rhGH) has transformed growth hormone deficiency (GHD) treatment. However, the possibility and rationality for flexible time regimen are pending.ObjectiveWe studied the efficacy of biweekly versus weekly PEGylated rhGH (PEG-rhGH) therapy in GHD children.Design, Setting, and PatientsThis multicenter, phase IV trial with a non-inferiority threshold ≥20% enrolled 585 Tanner stage I GHD children.InterventionSubjects randomly received 0.20 mg/kg once-weekly or biweekly PEG-rhGH, or 0.25 mg/kg.w rhGH once daily for 26 weeks.Main Outcome MeasureThe primary outcome was height SD scores for chronological age (HtSDSCA) at week 26 and safety measurements including adverse events (AEs), IGF-2, and IGFBP-2 changes.ResultsAt week 26, the median HtSDSCA changed from −2.75, −2.82, and −2.78 to −2.31, −2.43, and −2.28 with weekly and biweekly PEG-rhGH, and daily rhGH, respectively. The difference in HtSDSCA was 0.17 ± 0.28 between weekly and biweekly PEG-rhGH, and 0.17 ± 0.27 between daily rhGH and biweekly PEG-rhGH, failing the non-inferiority threshold. Nevertheless, the height velocity of children receiving biweekly PEG-rhGH reached 76.42%–90.34% and 76.08%–90.60% that of children receiving weekly PEG-rhGH and daily rhGH, respectively. The rate of AEs was comparable among the groups. No statistical difference was observed in IGF-2 and IGFBP-2 levels among the groups. IGFBP-2 levels decreased over time in all groups, with no notable difference in IGF-2 and IGFBP-2 changes among the three treatment groups.ConclusionsAlthough notably promoted height velocity, biweekly PEG-rhGH failed the non-inferiority threshold as compared with either weekly PEG-rhGH or daily rhGH. Compared with short-term rhGH, long-acting PEG-rhGH did not significantly increase tumor-associated IGF-2 and IGFBP-2 expressions.Clinical Trial Registrationclinicaltrials.gov, identifier NCT02976675.