Endocrine functioning in multitransfused prepubertal patients with homozygous beta-thalassemia

Endocrine and bone complications in β-thalassemia intermedia: current understanding and treatment

Thalassemia intermedia (TI), also known as nontransfusion dependent thalassemia (NTDT), is a type of thalassemia where affected patients do not require lifelong regular transfusions for survival but may require occasional or even frequent transfusions in certain clinical settings and for defined periods of time. NTDT encompasses three distinct clinical forms: β-thalassemia intermedia (β-TI), Hb E/β-thalassemia, and α-thalassemia intermedia (Hb H disease). Over the past decade, our understanding of the molecular features, pathophysiology, and complications of NTDT particularly β-TI has increased tremendously but data on optimal treatment of disease and its various complications are still lacking. In this paper, we shall review a group of commonly encountered complications in β-TI, mainly endocrine and bone complications.

Adrenal insufficiency is prevalent in HbE/β-thalassaemia paediatric patients irrespective of their clinical severity and transfusion requirement

OBJECTIVES

Transfusion dependency is known to cause endocrinopathies in patients with thalassaemia such as adrenal insufficiency, because transfusion-related iron overload is injurious to endocrine organs. Children with HbE/ß-thalassaemia vary greatly in red cell transfusion requirement and some are transfusion dependent (TD), whereas others are nontransfusion dependent (NTD). Because iron overload is thought to be the primary cause of adrenal insufficiency, TD children with HbE/ß-thalassaemia are considered likely candidates for the development of adrenal insufficiency, while the adrenal function of NTD children is generally considered to be normal. As yet, the prevalence of adrenal insufficiency among children with NTD HbE/β-thalassaemia is not known. The present study was performed to (i) assess the prevalence of adrenal insufficiency in children with both TD and NTD HbE/β-thalassaemia and to evaluate whether there is any difference in the prevalence of adrenal insufficiency between both groups and (ii) determine the type of adrenal insufficiency (primary or secondary).

METHODS

We investigated the prevalence of adrenal insufficiency among TD (n = 42) and NTD (n = 43) children with HbE/β-thalassaemia by assessing morning serum cortisol levels, and we distinguished between primary and secondary adrenal insufficiency by assessing the cortisol responses following the 1- and 250-μg ACTH stimulation tests.

RESULTS

The prevalence of adrenal insufficiency among TD and NTD children with HbE/β-thalassaemia was 50% and 53·5%, respectively. By using the 250-μg ACTH stimulation test, at least 39% and 23·5% were diagnosed with adrenal gland hypofunction in TD and NTD children, respectively.

CONCLUSION

This is the first study to show that adrenal insufficiency is common among all children with HbE/β-thalassaemia, irrespective of their transfusion history or requirement. Our findings have important implications for the clinical management of these children.

Thyroid function status and echocardiographic abnormalities in patients with Beta thalassemia major in bahrain

Background:

Thyroid gland dysfunction and echocardiographic cardiac abnormalities are well-documented in patients with transfusion dependent beta-thalassemia major (β-TM).

Aim:

This cross-sectional analytic study was conducted to investigate left ventricle (LV) diastolic and systolic function using pulsed Doppler (PD) and tissue Doppler (TD) echocardiography and correlate that with serum level thyroid stimulating hormone in patients with β-TM.

Methods:

The study was conducted on patients with β-TM (n = 110, age 15.9 ± 8.9 years) and compared with a control group (n = 109, age 15.8 ± 8.9 years). In all participants, echocardiographic indices of PD and TD were performed and blood samples were withdrawn for measuring the serum level of TSH, free T4, and ferritin. A linear regression analysis was performed on TSH level as the dependent variable and serum ferritin as independent. Stepwise multiple regression analysis was used to determine the odds ratio of different biochemical and echo variables on the risk of developing hypothyroidism.

Results:

Patients with β-TM compared with controls had thicker LV septal wall index (0.65 ± 0.26 vs. 0.44 ± 0.21 cm/M², P < 0.001), posterior wall index (0.65 ± 0.23 vs. 0.43 ± 0.21 cm/m², P < 0.01) and larger LVEDD index (4.35 ± 0.69 vs.3.88 ± 0.153 mm/m², P < 0.001). In addition, β-TM patients had higher transmitral E wave velocity (E) (70.81 ± 10.13 vs. 57.53 ± 10.13 cm/s, P = 0.02) and E/A ratio (1.54 ± 0.18 vs. 1.23 ± 0.17, P < 0.01) and shorter deceleration time (DT) (170.53 ± 13.3 vs. 210.50 ± 19.20 m sec, P < 0.01). Furthermore, the ratio of transmitral E wave velocity to the tissue Doppler E wave at the basal septal mitral annulus (E/Em) was significantly higher in the β-TM group (19.68 ± 2.81 vs. 13.86 ± 1.41, P < 0.05). The tissue Doppler systolic wave (Sm) velocity and the early diastolic wave (Em) were significantly lower in the β-TM group compared with controls with Sm, 4.82 ± 1.2 vs. 6.22 ± 2.1 mm/sec, P < 0.05 and (Em), 3.51 ± 2.7 vs. 4.12 ± 2.5 mm/sec. P < 0.05, respectively). The tricuspid valve velocity was significantly higher in β-TM patients compared with controls 2.85 ± 0.56 vs. 1.743 ± 0.47 m sec, respectively, P < 0.01). The prevalence of subclinical hypothyroidism in patients with β-TM was 15.4%, with significantly higher mean serum TSH compared with controls (6.78 ± 1.5 vs. 3.10 ± 1.02 μIU/mL, P < 0.01) and positively correlated with the serum ferritin level (r = 0.34, P = 0.014). On multiple regression analysis, the LV mass, LVEF%, and E/A ratio were not positive predictors of hypothyroidism in patients with β-TM.

Conclusion:

We conclude that patients with β-TM had a high prevalence of subclinical hypothyroidism of 15.4%. Thyroid stimulating hormone was significantly high and positively correlated with the serum ferritin level. Echo cardiographic pulsed Doppler showed a restrictive LV diastolic pattern suggestive of severe diastolic dysfunction with preserved left ventricle systolic function.

Study of the effect of iron overload on the function of endocrine glands in male thalassemia patients

Background:

Iron overload is an important issue in the state of thalassemic patients due to the harmful effect of high concentration of iron deposited in different tissues in human body including endocrine glands. In the present work, an attempt is carried out to estimate the effect of iron overload in thalassemic patients on the function of endocrine glands through the estimation of their ability to secrete adequate amounts of certain hormones.

Materials and Methods:

Seventy eight male children with beta-thalassemia, in the age-group of 4–11 years, were enrolled for this research. These children were being treated with frequent transfusions and long-term iron chelation therapy. Thirty age and sex matched children without thalassemia constituted the control group. Ferritin and different hormones were estimated by ELISA technique.

Results:

The results showed a mild reduction in the function of endocrine glands through the decrease in the level of some hormones. These changes due mainly to the hypoxia and precipitation of iron in certain glands and overlapping with the synthesis or secretion of the hormones.

Conclusion:

There is a different hormonal disturbances in beta thalassemia patients. Reduction of total body iron store is an important goal of the treatment of thalassemia and measuring the hormones concentration is necessary for the follow up of the thalassemic patients especially during puberty.

High prevalence of "biochemical" adrenal insufficiency in thalassemics: is it a matter of different testings or decreased cortisol binding globulin?

CONTEXT

High prevalence of "biochemical" adrenal insufficiency (AI) in thalassemics has been reported. However, "clinical" AI is rare.

AIM

The aim was to determine whether cortisol binding globulin (CBG) or tests used in assessing adrenal function contributed to the abnormally high prevalence of biochemical AI.

SETTING

The study was conducted at Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.

PARTICIPANTS

Participants included 56 children and adolescents with thalassemia and 44 controls.

MAIN OUTCOME MEASURES

Serum CBG and adrenal function test results assessed by 1 μg cosyntropin test and insulin tolerance test (ITT) were measured. Free cortisol index (FCI) calculated by total cortisol (TC)/CBG and calculated free cortisol (cFC) were determined.

RESULTS

Mean (sd) CBG levels were comparable between patients and controls [45.2 (11.0) vs. 47.0 (8.6) mg/liter]. Peak TC, FCI, and cFC after cosyntropin test were lower in thalassemics [TC, 15.2 (4.0) vs. 18.9 (3.1) μg/dl; FCI, 3.4 (0.8) vs. 4.2 (1.2) μg/mg, P <0.001; and cFC, 1.03 (0.38) vs. 1.44 (0.61) μg/dl, P = 0.008]. Thirty of 56 thalassemics (53.6%) had AI, defined as having peak TC of less than 16 μg/dl. ITT was performed in 26 of those 30 patients. Five of 26 patients had peak TC after an ITT of at least 20 μg/dl. As a result, the estimated frequency of AI in the entire patient group was reduced by approximately 10%.

CONCLUSION

The 1 μg cosyntropin test could be an adrenal function screening test in thalassemics. However, for definite diagnosis, ITT should be performed in those having peak total cortisol of less than 16 μg/dl after the 1 μg cosyntropin test.

Reproductive hormones and hypothalamic-pituitary-ovarian axis in female patients with homozygous beta-thalassemia major

INTRODUCTION

Homozygous beta-thalassemia major (hbeta-TM) is an autosomal recessive hemoglobinopathy with prominent endocrine complications. Our aims were to evaluate reproductive hormones, hypothalamic-pituitary-ovarian axis, and fertility in female patients with hbeta-TM.

PATIENTS AND METHODS

One hundred forty-four female patients with hbeta-TM, aged 18 years or above were enrolled in the study. Seventy-four age-matched healthy female volunteers served as controls. Two blood samples were drawn from each subject at 20-minute intervals for the determination of the resting levels of the following hormones: luteinizing hormone, follicle-stimulating hormone, estradiol, insulin-like growth factor-1, and insulin-like growth factor binding protein-3. The hypothalamic-pituitary-ovarian axis was also assessed using the gonadotropin-releasing hormone test. Menstruation status and growth rate were also noted. Puberty was assessed in both groups by Tanner classification.

RESULTS

The mean age of puberty in the control group and hbeta-TM patients was 10.8+/-1.2 and 16.4+/-2.2 years, respectively (P=0.01). The mean age of menarche was 11.4+/-1.3 and 16.8+/-2.1 years in control subjects and patients with thalassemia, respectively (P=0.01). Of studied subjects with hbeta-TM, 61 (42.4%) were short in stature (height below the third percentile and below -2 SD scores). The baseline and peak levels of luteinizing hormone, follicle-stimulating hormone, and estradiol after gonadotropin-releasing hormone test in thalassemic group were significantly lower than in the control group.

CONCLUSIONS

Further interventional studies are warranted to better clarify the treatment options to attain normal puberty and sexual maturation in patients with thalassemia.

The pituitary-adrenal axis in adult thalassaemic patients

OBJECTIVE

We previously described in young thalassaemic patients an altered cortisol and ACTH responsiveness suggesting an impaired adrenocortical reserve. Owing to iron overload, a worsening of adrenal function should be expected in adult patients.

DESIGN

In 124 adults with beta-thalassaemia, urinary free cortisol (UFC) and plasma ACTH levels were determined and compared with those measured in 150 controls. In 45 patients, cortisol was measured in response to: i) tetracosactide 1 microg as an i.v. bolus (low-dose test, LDT) and ii) tetracosactide 250 microg infused i.v. over 8 h (high-dose test, HDT).

RESULTS

UFC and serum cortisol were within the reference range in all patients. Conversely, basal plasma ACTH values were above the upper limit of the normal range in 19 patients. There were no statistically significant differences in the mean values of UFC, basal serum cortisol and plasma ACTH between patients and controls. A subnormal cortisol response to the LDT was registered in 18 out of 56 patients. Three of these patients also displayed a subnormal response to the HDT, together with elevated baseline plasma ACTH levels. In the LDT, a positive correlation was found between basal and peak cortisol values (P<0.0001). The latter were negatively correlated with basal ACTH values in both LDT (P<0.0001) and HDT (P<0.0001).

CONCLUSIONS

Adult thalassaemic patients often present a subtle impairment of adrenocortical function. This may become clinically relevant in case of major stressful events. Thus, we recommend an assessment of adrenocortical function in all adult thalassaemic patients.

Growth and endocrine function in thalassemia major in childhood and adolescence

BACKGROUND

Thalassemia major is an inherited hemoglobin disorder characterized by chronic anemia and iron overload due to transfusion therapy and gastrointestinal absorption. Iron overload causes most of the associated mortality and morbidity and frequently involves the endocrine glands.

AIM

To review the most pertinent literature on the topic.

METHODS

One hundred and twenty-three papers were evaluated.

RESULTS

Disproportionate short stature is frequent and becomes more evident at puberty because of the lack of growth spurt. Later on, partial height recovery may occur. Long-term treatment with recombinant human GH seems ineffective to improve final height. Pubertal development is characterized by a clinical spectrum ranging from hypogonadism to a simple delay in starting and developing of puberty. Hormonal replacement is mandatory in cases of absent or arrested puberty. Pancreatic beta-cells function may be impaired during adolescence or later on. Its impairment ranges from hyperinsulinemia, secondary to insulin resistance, with normal glucose tolerance to beta-cells failure with insulin-dependent diabetes mellitus. Primary hypothyroidism may affect thalassemic patients from the second decade of life. The thyroid dysfunction may be reversible (if an intensive chelation therapy regimen is started in the precocious phase), stationary, or slowly progressive. Central hypothyroidism is less common and autoimmune thyroiditis absent.

CONCLUSION

Despite the improvement of the treatment, the involvement of the endocrine system still burdens the life of these patients. Further therapeutic improvement would reasonably reduce morbidity and, hopefully, mortality of thalassemic patients and make the endocrine disorders easier to treat.

Thalassaemia and aberrations of growth and puberty

Endocrine dysfunction in Thalassaemia major (TM) is a common and disturbing complication, which requires prompt recognition and treatment. The contribution of the underlying molecular defect in TM to the development of endocrinopathies is significant because the patients with the more severe genetic defects have a greater rate of iron loading through higher red cell consumption. TM patients frequently present delay of growth and puberty with reduction of final height. The pathogenesis of growth failure is multifactorial and is mainly due to chronic anemia and hypoxia, chronic liver disease, zinc and folic acid deficiency, iron overload, intensive use of chelating agents, emotional factors, and endocrinopathies (hypogonadism, delayed puberty, hypothyroidism) and GH-IGF-1 axis dysregulation. Although appropriate iron chelation therapy can improve growth and development, TM children and adolescents treated intensively with desferrioxamine remain short as well, showing body disproportion between the upper and lower body segment. Body disproportion is independent of pubertal or prepubertal period of greater height gain. Treatment with recombinant GH (rhGH) is recommended when GH deficiency is established, and even so, the therapeutic response is often non satisfactory. Growth acceleration is mostly promoted with sex steroids in children with associated pubertal delay. Sexual complications in TM, which include Delayed Puberty, Arrested Puberty and Hypogonadism, present the commonest endocrine complication. Iron deposition on gonadotroph cells of the pituitary leads to disruption of gonadotrophin production which is proven by the poor response of FSH and LH to GnRH stimulation. In the majority of patients gonadal function is normal as most women with Amenorrhea are capable of achieving pregnancy with hormonal treatment and similarly men with azoospermia become fathers. Secondary Hypogonadism appears later in life, and is manifested in women as Secondary Amenorrhea and in men as decline in sexual drive and azzoospermia. The damage to the hypothalamus and pituitary is progressive, even when intensive chelating therapy is given and the appearance of Hypogonadism in both sexes is often unavoidable. Close follow up and proper management is crucial for every patient with TM. Early recognition of growth disturbance and prevention of hypogonadism by early and judicious chelation therapy is mandatory for the improvement of their quality of life. Patients with TM can now live a better life due to modern advances in their medical care and our better understanding in the pathogenesis, manifestation and prevention of endocrine complications.

Comparison of Oral and Subcutaneous Iron Chelation Therapies in the Prevention of Major Endocrinopathies in β-Thalassemia Major Patients

While hypertransfusion and subcutaneous iron chelation therapy have increased longevity of patients with beta-thalassemia (thal) major, endocrinopathies have become more common and impair the quality of their lives. Additionally, subcutaneous iron chelation therapy is an uncomfortable experience and can prevent patients from regular compliance with iron chelation therapy. We compared the efficacy of oral deferiprone (L1) to subcutaneous desferrioxamine (DFO) chelation therapy for the prevention of major endocrinopathies (growth hormone insufficiency, diabetes mellitus and gonadal dysfunction) among patients with beta-thal major to see if we could offer these patients an easier and more painless way to reduce their body iron load and related endocrine complications.

Adrenal glands in beta-thalassemia major: magnetic resonance (MR) imaging features and correlation with iron stores

This study aimed at describing the magnetic resonance (MR) imaging features of the adrenal glands in beta-thalassemic patients and at investigating the relation between adrenal and hepatic siderosis. Adrenal signal intensity (SI) was retrospectively assessed on abdominal MR studies of 35 patients with beta-thalassemia major undergoing quantification of hepatic siderosis and 12 healthy controls, using T1-(120/4/90), intermediate-(120/4/20), and T2*-(120/15/20) weighted GRE sequences. Adrenal SI was graded as grade 0 (normal SI on all sequences), grade 1 (hypointensity on T2* alone), or grade 2 (hypointensity on at least T2*). Adrenal size was measured in the thalassemic patients and compared with normative data. Liver-to-muscle (L/M) SI ratios, expressing hepatic siderosis, were estimated on each sequence. Serum ferritin levels were recorded. Adrenal hypointensity (grades 1 and 2) was noted in 24/35 (68.6%) patients. L/M ratios correlated significantly with adrenal SI in all sequences. Patients with grade 1 and grade 2 adrenal SI had significantly decreased L/M ratios compared with grade 0. Serum ferritin correlated significantly with L/M values but not with adrenal SI. Adrenal size was within normal limits. Diffuse hypointensity in normal-sized adrenals is a common MR finding in beta-thalassemic patients and correlates with the degree of hepatic siderosis.

Gonadal function of young patients with beta-thalassemia following bone marrow transplantation

Bone marrow transplantation (BMT) can induce short- and long-term impairment of gonadal function. Patients with beta-thalassemia represent a special group, as their primary diagnosis and its treatment modalities are responsible for gonadal dysfunction. To address the effect of BMT on puberty and gonadal function, we investigated 25 patients (12 males) with thalassemia who received allogenic BMT during childhood or adolescence and at the post-transplant evaluation were at an age that the pubertal process should have started. Pubertal stage by Tanner of breast and pubic hair, as well as testicular volume were assessed pre-BMT once and post-BMT at least twice. Menstrual history was recorded. FSH, LH, testosterone and estradiol levels were also determined. The impact of BMT appears to be different in the two sexes. Males seem to have higher tolerance, as all males who were pubertal at the time of BMT had normal testosterone, and all but one normal gonadotropin levels. From those who were prepubertal at BMT, 62% proceeded to normal pubertal development. Post-menarcheal females seem to be an extremely sensitive group to the deleterious effect of the transplantation process, as 100% of the post-menarcheal females exhibited amenorrhea and elevated gonadotropin levels. These findings are important for pre- and post-BMT counseling.

Metabolic and endocrinologic complications in beta-thalassemia major: a multicenter study in Tehran

ABSTRACT : BACKGROUND : The combination of transfusion and chelation therapy has dramatically extended the life expectancy of thalassemic patients. The main objective of this study is to determine the prevalence of prominent thalassemia complications. METHODS : Two hundred twenty patients entered the study. Physicians collected demographic and anthropometric data and the history of therapies as well as menstrual histories. Patients have been examined to determine their pubertal status. Serum levels of 25(OH) D, calcium, phosphate, iPTH were measured. Thyroid function was assessed by T3, T4 and TSH. Zinc and copper in serum were determined by flame atomic absorption spectrophotometry. Bone mineral density (BMD) measurements at lumbar and femoral regions have been done using dual x-ray absorptiometry. The dietary calcium, zinc and copper intakes were estimated by food-frequency questionnaires. RESULTS : Short stature was seen in 39.3% of our patients. Hypogonadism was seen in 22.9% of boys and 12.2% of girls. Hypoparathyroidism and primary hypothyroidism was present in 7.6% and 7.7% of the patients. About 13 % of patients had more than one endocrine complication with mean serum ferritin of 1678 +/- 955 micrograms/lit. Prevalence of lumbar osteoporosis and osteopenia were 50.7% and 39.4%. Femoral osteoporosis and osteopenia were present in 10.8% and 36.9% of the patients. Lumbar BMD abnormalities were associated with duration of chelation therapy. Low serum zinc and copper was observed in 79.6% and 68% of the study population respectively. Serum zinc showed significant association with lumbar but not femoral BMD. In 37.2% of patients serum levels of 25(OH) D below 23 nmol/l were detected. CONCLUSION : High prevalence of complications among our thalassemics signifies the importance of more detailed studies along with therapeutic interventions.

Growth hormone secretion in polytransfused prepubertal patients with homozygous beta-thalassemia. Effect of long-term recombinant GH (recGH) therapy

Growth was monitored in 133 male and 150 female North Sardinian prepubertal patients with homozygous beta-thalassemia in order to ascertain the incidence of GH deficiency (GHD) and the effects of long-term recombinant GH (recGH) treatment on growth velocity and bone maturation. A significant reduction in growth velocity and a fall in IGF-I levels was observed in 19 male and 16 female patients (12.3%). Their peak GH responses to GHRH (5.45+/-0.78 and 4.99+/-0.86 ng/ml) and clonidine administration (4.21+/-0.32 and 4.15+/-0.27 ng/ml in males and females, respectively) were markedly reduced with respect to control subjects (p<0.01). No statistically significant correlation was found between chronological age, number of blood units received, plasma ferritin levels and plasma IGF-I levels as well as with peak GH response to stimulation. Thalassemic patients with GHD had plasma ferritin levels (1382.44+/-160.34 and 1255.23+/-139.81 ng/ml in males and females, respectively) significantly lower than those recorded in the other patients (2848.94+/-283.61 and 3077.82+/-220.51 ng/ml). Patients with GHD were treated with recGH for an average period of 59 months (range 26-124). Treatment was able to restore growth and to increase significantly plasma IGF-I levels. Growth velocity at the end of the first yr of treatment was 6.78+/-1.21 and 6.11+/-0.85 cm/yr in males and females, respectively. Growth velocity values and plasma IGF-I levels remained significantly higher than basal values throughout the period of treatment. However, treatment was unable to normalize bone maturation since bone age values were always reduced with respect to chronological age. No incidence of side effects was observed. These data indicate that GHD, when present, is one but not the sole cause of delayed bone maturation and height deficiency in thalassemia.

Assessment of thyroid function in two hundred patients with beta-thalassemia major

Despite improved hematologic care, multiendocrine dysfunction is a common complication of homozygous transfusion-dependent beta-thalassemia. In this study our goal was to estimate the prevalence of thyroid dysfunction in a large homogenous group of thalassemic patients. Two hundred patients with beta-thalassemia major (100 males and 100 females; mean age, 23.2 +/- 6.7 years; age range 11-43 years), regularly transfused and desferioxamine chelated, were randomly selected from a pool of approximately 800 patients with beta-thalassemia followed in our department. Thyroid function and iron-load status were evaluated by measurements of free thyroxine (FT4), free triiodothyronine (FT3), thyrotropin (TSH), and serum ferritin levels. Of the subgroup of patients who proved to have normal thyroid hormone values, 26 (12 males, 14 females; mean age, 23.6 +/- 6.8 years; age range, 15-36 years) were randomly selected and underwent a standard TRH stimulation test. Thyroid dysfunction was defined as follows: overt hypothyroidism: low FT4 and/or FT3, increased TSH levels; subclinical hypothyroidism: normal FT4, FT3, increased TSH levels; exaggerated TSH response: normal FT4, FT3, normal basal TSH, deltaTSH > or = 21 microIU/mL (TSH levels measured prior and 30 minutes after intravenous TRH administration). Normal thyroid hormone values were found in 167 (83.5%) of the 200 patients studied. Eight (4%) of the remaining patients had overt hypothyroidisim, and 25 (12.5%) had subclinical hypothyroidism. Exaggerated TSH response to TRH was revealed in 7 of the 26 patients with normal hormone values tested (26.9%). Antithyroglobulin and anti-thyroid peroxidase (TPO) antibody titers were negative in 191 patients (95.5%). Mean ferritin levels in hypothyroid and euthyroid patients were 2707.66 +/- 1990.5 mg/L and 2902.9 +/- 1997.3 mg/L, respectively, (p = 0.61), indicating no correlation between ferritin levels and thyroid functional status. Mean ferritin levels in the patients who responded normally to TRH stimulation and in those who overresponded, were 2,586 +/- 1791 mg/L and 3,228 +/- 2473 mg/L, respectively (p = 0.46; NS). Thyroid failure is a rather rare endocrine complication in patients with beta-thalassemic from Greece. In our series, no case of central hypothyroidism was observed. No correlation was found between thyroid functional status and ferritin plasma levels. Approximately 1 of 5 beta-thalassemic patients with normal thyroid hormone values showed an exaggerated TSH response to TRH test. It is to be investigated how many of these patients will establish overt or subclinical hypothyroidism in the future.

Reproductive health in individuals with homozygous beta-thalassemia: knowledge, attitudes, and behavior

OBJECTIVE

To review the reproductive health knowledge, attitudes, and behaviors of persons with homozygous beta-thalassemia.

DESIGN

Case-control study.

SETTING

Patients treated at a tertiary hospital and community-based healthy controls.

PARTICIPANT(S)

One hundred and thirty persons, 16 years of age or older, who had homozygous beta-thalassemia and were attending hospital for regular blood transfusion, and 99 demographically matched persons without thalassemia. ASSESSMENT TOOL: Reproductive health questionnaire.

RESULT(S)

104 (80%) persons with homozygous beta-thalassemia completed the questionnaire and were compared with 99 controls. Persons with homozygous beta-thalassemia were as likely as healthy peers to be in a relationship, employed full-time, sexually active, and using contraception and to have had children. Hypogonadotrophic hypogonadism was present in 55 (52.8%) patients, 46 (83.6%) of whom were compliant with hormone replacement therapy. Understanding of genetics and reproductive potential was suboptimal among persons with homozygous beta-thalassemia, and this group had a higher rate of unplanned pregnancy.

CONCLUSION(S)

This study suggests that with optimal therapy, most young adults with homozygous beta-thalassemia can achieve reproductive, sexual, and social experiences similar to those of their healthy peers.

Final height of thalassemic patients who underwent bone marrow transplantation during childhood

We evaluated the final height achieved by 47 patients who had bone marrow transplantation (BMT) for thalassemia major. Subjects were separated into two groups: patients who received BMT before 7 years of age and patients who received BMT after 7 years of age. Parental height and genetic target height (TH) were calculated. Our data indicated a strict correlation between age at time of transplant and final adult height. The patients whose age at transplant was <7 years had a less impaired growth rate than did patients who were >7 years. Moreover, greatest loss in height was observed in subjects who had higher serum levels of transaminase and ferritin and these biochemical parameters were strictly correlated to the final adult height. Mean final adult height, however, did not differ from the genetic target height in subjects who received BMT before 7 years of age and the final height SDS corrected for TH surpasses even the TH. In contrast, the subjects who received BMT after 7 years of age, failed to achieve their full genetic potential. In conclusion, short stature is present in a significant percentage of transplanted thalassemic children. The data in this study indicate a close effect of the age at time of transplant on subsequent growth rate, but the growth impairment in these subjects remain multifactorial.

Novel application of IGF-I and IGFBP-3 generation tests in the diagnosis of growth hormone axis disturbances in children with beta-thalassaemia

OBJECTIVE

Children with beta-thalassaemia major (beta-thal) frequently have growth retardation in the presence of low serum IGF-I and a normal GH response to pharmacological stimulation suggesting that they have GH insensitivity (GHIS). This study was carried out to study the cause of their growth retardation.

DESIGN

We studied IGF-I and IGFBP-3 generation after exogenous GH administration for four days, in 15 prepubertal controls (C) and 41 prepubertal beta-thal patients divided into three groups according to their growth status: (Group 1) 15 with normal growth (N-thal) (Group 2) 16 with decelerated growth (D-thal) and (Group 3) 10 with short stature (S-thal), in order to determine whether GHIS is the cause of their growth retardation.

MEASUREMENTS

IGF-I and IGFBP-3 were measured daily, before and for 4 days after daily administration of 0.1 IU/kg hGH, in 3 groups of prepubertal beta-thal patients and normal controls.

RESULTS

N-thal and C had similar basal serum IGF-I (142 +/- 52 and 196 +/- 56 ng/ml, respectively) and IGFBP-3 concentrations (2.07 +/- 0.49 and 2.66 +/- 0.41 mg/l, respectively) as well as a similar percent increase of IGF-I (101 +/- 23% and 104 +/- 37%, respectively) and IGFBP-3 (52 +/- 36%, and 38 +/- 14%, respectively) during the generation tests. S-thal and D-thal had significantly lower basal IGF-I and IGFBP-3 concentrations (85 +/- 42 and 101 +/- 36 ng/ml; and 1.60 +/- 0.49 and 1.79 +/- 0.52 mg/l, respectively) as compared to N-thal and C (P < 0.001 and P < 0.005, respectively), and a significantly higher percent increase of IGF-I and IGFBP-3 during the generation tests (249 +/- 43 and 161 +/- 76%; and 121 +/- 99 and 73 +/- 35%, respectively) as compared to N-thal and C (P < 0.0001 and P < 0.01, respectively). Twenty-five percent of the growth retarded patients had classic GH deficiency (GHD) and percent increases of IGF-I and IGFBP-3 in the generation tests (164 +/- 86% and 80 +/- 49%, respectively) which were similar to those of the remaining growth-retarded children.

CONCLUSION

The greater percent increases of IGF-I and IGFBP-3 in the generation tests of the growth retarded beta-thal patients, both with and without GHD, strongly suggest impaired GH secretion rather than GHIS as the cause of their growth retardation. We conclude that the IGF-I and IGFBP-3 generation tests are useful tools for the study not only of GHIS but also of GH secretory disorders in patients with beta-thal and short stature that can easily be performed in an outpatient setting as an initial test to identify the patients that may benefit from GH therapy.

The effect of 3 years of recombinant growth hormone therapy on glucose metabolism in short Chinese children with beta-thalassemia major

Growth retardation and diabetes mellitus are common in children and adolescents with beta-thalassemia major despite hypertransfusion regimen and iron chelation therapy. The purpose of this study was to investigate the effects of growth hormone (GH) treatment on glucose metabolism in children with beta-thalassemia major. GH therapy for 3 years improved the height SD scores of eight short prepubertal Chinese children with beta-thalassemia major from -2.15 +/- 0.90 to -1.14 +/- 0.78 (paired t-test, p = 0.01) without excessive advancement in bone age (ABA/CA = 0.95 +/- 0.27). There was no deleterious effect on glucose metabolism with no change in fasting blood sugar, serum fructosamine, fasting and stimulated insulin to intravenous glucose infusion (sum of 1+3 min insulin, In 1+3'; incremental insulin 0-10 min area above fasting concentrations, deltaInAUC0-10'; ratio of incremental 0-10 min insulin area above fasting concentrations over glucose area above fasting concentrations, delta0-10'AUCIn/G; ratio of incremental 0-10 min insulin over peak glucose above basal 0-10 min, delta0-10'InAUC/deltaGPeak), and glucose disappearance coefficient (Kg). Short term GH therapy improves the height of children with beta-thalassemia major but the effect of treatment on final height still needs to be determined.

Growth hormone treatment in short children with beta-thalassemia major

The effect of one year recombinant human growth hormone (rhGH) treatment on growth rate and bone age was studied in ten short prepubertal children with beta-thalassemia major (age range 7.10-12.03 yr) with normal GH response to provocative stimuli. rhGH was given subcutaneously every day in a dose of 28 IU/m2/week. In the 10 children who completed 12 months of treatment the growth velocity increased from 4.22+/-0.81 cm/yr (-1.38+/-0.80 SDS for CA) to 7.61+/-1.16 cm/yr (+2.27+/-1.64 SDS for CA). IGF-I was low before treatment, 138.3 +/-38.9 ng/ml, and rose significantly to 232.2+/-122.1, 243.2+/-98.4 and 227.5+/-86.2 at 3, 6 and 12 months post-treatment, respectively (p<0.01). Bone maturation was accelerated in proportion to the increase in chronological age. The mean pre-treatment bone age in the ten children was 8.20+/-1.97 and increased to 9.55+/-1.80 yr after one year of treatment. Our data demonstrate that GH treatment of thalassemic children with normal GH reserve and low serum IGF-I concentrations with supraphysiological doses of rhGH for one year can cause a significant increase in serum IGF-I levels and growth velocity, but it remains to be elucidated whether long-term administration will affect the final height.

High prevalence of thyroid dysfunction in adult patients with beta-thalassemia major submitted to amiodarone treatment

Amiodarone may induce hyper- or hypothyroidism. Patients with beta-Thalassemia Major (beta-Thal) have an increased prevalence of primary hypothyroidism and often require amiodarone for hemosyderotic cardiomyopathy. Aim of this study was to retrospectively evaluate thyroid function in beta-Thal adult patients on long-term amiodarone. The study group consisted of twenty-two (21 males, 1 female; age: 23-36 yr) beta-Thal patients submitted to long-term (3-48 months) amiodarone therapy from January 1991 to July 1996. Controls included 73 beta-Thal patients (23 males and 50 females aged 25-35 yr) not treated with amiodarone. In all cases serum free thyroid hormones, thyrotropin and thyroid autoantibodies were evaluated. A higher prevalence of overt hypothyroidism (5/22 [22.7%]) as compared to controls (3/73 [4.1%], p=0.02) was found in beta-Thal patients < or = 3 months after starting amiodarone, while the prevalence of subclinical hypothyroidism was similar in amiodarone-treated (18.2%) and untreated (15%) beta-Thal patients. Overt hypothyroidism resolved spontaneously after amiodarone withdrawal in 1 case, while the remaining patients were maintained euthyroid on amiodarone by L-thyroxine administration. After 21-47 months of amiodarone therapy, 3 patients (13.6%) developed thyrotoxicosis (2 overt and 1 subclinical), which remitted shortly after amiodarone withdrawal. No case of hyperthyroidism was observed in beta-Thal controls (p=0.012 vs amiodarone-treated patients). In conclusion, amiodarone administration is often associated in adult beta-Thal patients to a rapid progression of the pre-existing subclinical hypothyroidism, but transient thyrotoxicosis may also be observed after a longer period of therapy. These findings should be carefully considered in the management of these patients.

Magnetic resonance imaging evaluation of the pituitary gland and hypothalamus in thalassaemic children with elevated serum ferritin levels

OBJECTIVE

Despite modern treatment with hypertransfusion and chelation therapy, growth retardation continues to be observed in a significant proportion of thalassaemic children. The underlying reason remains unclear, but hypothalamic-pituitary axis disorder has been implicated. We aimed to assess iron overloading in the hypothalamus and pituitary gland in thalassaemic children with elevated serum ferritin, with and without growth retardation.

METHODOLOGY

Twelve thalassaemic children on hypertransfusion and chelation therapy with high serum ferritin were investigated with magnetic resonance imaging (MRI). Five children, all over 10 years of age, had growth retardation. Gradient recalled echo sequence was used to highlight any susceptibility effect that could be due to iron in the hypothalamus or pituitary gland.

RESULT

There was no evidence of abnormal hypointense signal in the hypothalamus or pituitary gland in the patients studied, regardless of the presence of growth retardation.

CONCLUSION

There was no apparent characteristic MRI appearances of iron deposition in the hypothalamus or pituitary gland in thalassaemic children with high serum ferritin.

Amenorrhea in beta-homozygous thalassemia major

Hemolytic anemias, and, in particular, beta-homozygous thalassemia, derange all vital organs. A shift of the survival curve to the right has been achieved, thanks to the intensive programs of blood transfusion; iron chelation; infectious control; and, most recently, bone marrow transplantation. Metabolic and endocrine abnormalities do occur, albeit in less severe forms in comparison to available data from 10 to 20 years ago, for example, osteopenia. The most commonly encountered hormonal disorder is the attenuation of gonadal function on a downstream basis, linked to iron deposition in the hypothalamic-pituitary gonadotropin axis. A transition, from low-amplitude endogenous GnRH pulses to apulsatility of LH patterns, precedes the inability of the pituitary gonadotrope to respond to the GnRH decapeptide administered either as an acute bolus injection or in a pulsatile manner for up to 7 days.

Growth, puberty and endocrine function in beta-thalassaemia major

Although delay in onset of puberty is a common cause of growth failure in adolescent thalassaemic patients, growth retardation could also be due to iron overload, the toxic effects of desferrioxamine, or the development of other endocrinopathies such as GH insufficiency or primary hypothyroidism. Abnormal body proportions with truncal shortening are commonly seen and could be due to the disease itself, iron toxicity, delay in puberty or the toxic effects of desferrioxamine. The absence of a pubertal growth spurt during spontaneous or induced puberty is detrimental to the achievement of a normal final adult height. Low serum IGF-I and normal GH reserve in short thalassaemic children imply that a state of relative GH resistance exists. The rise in IGF-I and improvement in growth with GH therapy suggest that this GH resistance is only partial. Although the results of short-term GH therapy are encouraging, the impact of treatment on final height of non-GH deficient short thalassaemic children remains uncertain. Multiple endocrinopathies, including hypogonadism, hypothyroidism and diabetes mellitus, occur mainly in older patients who tend to have high serum ferritin levels. Prognosis for survival is greatly improved if the serum ferritin is kept below 2000 micrograms/l by regular chelation. Chelation therapy initiated early before the accumulation of a significant iron burden or dosages of desferrioxamine in excess of 50 mg/kg/day should be avoided. Serum ferritin should be checked regularly and the "toxicity index" should be used to monitor chelation therapy. In cases of delayed puberty, sexual development should be induced at an appropriate age.

Experience with thalassemia major in Al Baha

In a two-year retrospective review of the thalassemia program in our hospital, relevant clinical and laboratory items of information were extracted and analyzed. There were 12 regular attendants; seven males and five females, with a mean age of 6.9 +/- 3.3 years and a mean age at the time of diagnosis of 18.6 +/- 8.7 months. Mean hemoglobin at diagnosis was 6.5 +/- 1.1 g/dL and MCV was 67.9 +/- 4.6 fL. Predominant hemoglobin was HbF (30% to 98%). Presenting features included pallor, abdominal distention, hepatomegaly, splenomegaly and occasional fever. Mean pretransfusion hemoglobin was 8.3 +/- 1.5 g/dL and mean post-transfusion hemoglobin was 12.2 g/dL. Only two (16.7%) had weight less than the 5th percentile; six (50%) had weight >/=25th percentile while eight (66.7%) had height >/=10th percetile. Mean weight gain per year was 1.3 +/- 0.82 kg and linear growth rate was 4.27 +/- 1.66 cm. One patient was positive for hepatitis C virus (detected by antibody) and another was positive for both hepatitis B (both antigen and antibody) and C. Apart from admissions for routing blood transfusion, none of the patients were hospitalzed for any other morbid events in two years. High serum ferritin level (1482 +/- 766 mg/L) despite subcutaneous desferrioxamine remains a problem.

Fertility in beta thalassaemia major: a report of 16 pregnancies, preconceptual evaluation and a review of the literature

OBJECTIVES

To examine the pregnancies, mode of delivery and outcomes, review the literature on fertility and discuss preconceptual guidance for women with beta thalassaemia major.

DESIGN

An observational study.

SUBJECTS

Sixteen women with beta thalassaemia major.

SETTING

Two collaborating London teaching hospitals.

MAIN OUTCOME MEASURES

Pre-pregnancy assessment, pregnancy course, mode of delivery, gestational age at delivery and birthweight.

RESULTS

There were 16 pregnancies in 11 women. Three of these pregnancies were terminated. Of the 13 deliveries, there were two normal deliveries, one forceps delivery and 10 caesarean sections. The main findings in a further five women seeking fertility treatment were of hypogonadotrophic hypogonadism, diabetes and cardiomyopathy.

CONCLUSIONS

Pregnancy in women with beta thalassaemia major does not appear to have a deleterious effect on the course of the disease. No increased obstetric complications were encountered except for the high caesarean section rate, essentially due to cephalopelvic disproportion. A high incidence of cardiomyopathy and diabetes dictates a careful assessment before embarking on ovulation induction to treat the hypogonadotrophic hypogonadism which is common in these women.

Short stature in homozygous beta-thalassaemia is due to disproportionate truncal shortening

BACKGROUND AND OBJECTIVE

Growth failure in homozygous beta-thalassaemia has been recognized for many years, and has persisted despite major treatment advances. In this cross-sectional study, sitting and standing height were measured to determine whether growth failure was disproportionate.

DESIGN

Patient data were analysed in three age groups, 2-10 years, 11-18 years and 19 and over. Sitting height and subischial leg length were also determined in a cohort of parents (n = 19) and normal Greek adolescents (n = 32).

PATIENTS AND MEASUREMENTS

Of the known 156 patients with homozygous beta-thalassaemia in the State of Victoria, 154 (98.7%) attend our institution. Sitting and standing heights were measured, using Harpenden stadiometers, in 57 of 60 (95%) patients aged 2-18 years and in a random selection of 51 of 89 patients aged 19 and over (57%). Measurements are expressed as mean +/- SDS. Other data analysed included serum concentrations of ferritin, zinc, copper, FSH, LH, oestradiol and testosterone, according to standard laboratory assays, together with pubertal status and bone age in patients aged less than 19 years.

RESULTS

Standing height standard deviation scores in the 2-10 age group were -0.687 +/- 0.861 (n = 9), in the 11-18 age group were -1.838 +/- 1.413 (n = 48) and in the age group 19 and over were -1.175 +/- 1.126. In individuals aged 2-10 years, sitting height standard deviation scores (SDS) were -1.56 +/- 1.02, in individuals 11-18 years were -3.76 +/- 1.51 (n = 48), and in individuals 19 years and over were -2.77 +/- 1.20 (n = 51), compared with subischial leg length SDS which were, in individuals aged 2-10 years 0.214 +/- 0.91; in 11-18 years, -0.063 +/- 1.347, and in individuals 19 and over, 0.37 +/- 1.18. These data show that the reduction in standing height was the result of truncal shortening. Mean sitting height SDS was significantly lower in children with homozygous beta-thalassaemia, compared with their parents (P < 0.001), and in a subgroup of Greek adolescents with homozygous beta-thalassaemia compared with age and sex matched normal Greek adolescents (P < 0.001). No correlation was found between truncal shortening and other clinical and biochemical variables measured.

CONCLUSIONS

Short stature in our patients with homozygous beta-thalassaemia is due to disproportionate truncal shortening. The aetiology of truncal shortening in this patient group is likely to be multifactorial, although hypogonadism and chelation therapy may be contributory factors.

Circadian growth hormone secretion in short multitransfused prepubertal children with thalassaemia major

Growth hormone (GH) secretion was determined by evaluating circadian GH profiles for 24 h and GH responses to clonidine stimulation test and insulin-stimulated hypoglycaemia (ITT), in nine prepubertal children with beta-thalassaemia major (TM) and 17 with non-GH deficient short stature (NGHDSS). The TM children were multitransfused and had early and intensive chelation therapy. All patients had normal hypoglycaemia to ITT, with peak GH levels of 15.71 +/- 5.86 ng/ml for children with NGHDSS and 13.91 +/- 7.20 ng/ml for children with TM. Peak GH levels during a clonidine test were 17.54 +/- 5.30 and 17.15 +/- 1.38 ng/ml, respectively. The GH peak parameters such as the number of peaks, the integrated GH concentration and the area under the curve (AUC) were similar in both groups of children and reflected the total 24-h secretion and the daily and nocturnal secretion separately. An abnormal 24-h GH profile compatible with the diagnosis of endogenous neurosecretory GH dysfunction was found in only two out of nine children with TM and in four out of seven children with NGHDSS.

CONCLUSION

Our data suggest that growth hormone neurosecretory dysfunction is not a universal finding in children with thalassaemia major but might depend on the degree of iron deposit in the pituitary.

Growth hormone treatment of short Chinese children with beta-thalassaemia major without GH deficiency

OBJECTIVE

Despite regular transfusion and desferrioxamine treatment, growth failure is commonly seen in adolescent children with beta-thalassaemia major. The growth failure has been thought to be due to GH resistance rather than GH deficiency. We investigated the effect of GH on short non-GH deficient children with beta-thalassaemia.

DESIGN

Recombinant human GH was given in a dose of 0.14 IU/kg/day subcutaneously in an open study.

PATIENTS

Fifteen prepubertal Chinese children with beta-thalassaemia major (ranging from 7.16 to 14.7 years in age) with height -1.5 SD or more below the population mean for age and a growth velocity of less than 5 cm/year were treated with growth hormone for one year. All children had peak GH response > 15mlU/l to insulin induced hypoglycaemia and normal thyroid function and adrenal reserve.

MEASUREMENTS

Anthropometric measurements were performed every 3 months. Morning urine was tested twice weekly for glycosuria. Blood count, renal and liver function tests, fasting blood glucose, IGF-I and fructosamine levels were assessed at entry and every 3 months during treatment. Fasting insulin was measured before and after 3 and 12 months of GH treatment. Skeletal maturity was assessed before and after one year of treatment.

RESULTS

Treatment was stopped in two children after 6 months because of poor growth response and noncompliance with treatment and in one child at 9 months because of bone marrow transplantation. In the 13 children, the growth velocity increased from 3.6 +/- 0.7 cm/year to 8 +/- 1.2 cm/year after one year of GH treatment (P < 0.001). IGF-I was low before treatment (10.1 +/- 2.7 nmol/l), rising significantly to 15.8 +/- 4.8, 18.4 +/- 4.6, 19.3 +/- 6.4 and 21.9 +/- 7.5 nmol/l at 3, 6, 9 and 12 months of treatment (P < 0.005). The mean pretreatment bone age in the 13 children was 9.58 +/- 1.41 years and increased to 10.53 +/- 1.43 years after one year of treatment (delta BA/CA 0.95 +/- 0.3 years). None of the patients developed glycosuria or hypertension. There was no significant change in blood count, renal and liver function, thyroid function, fasting blood glucose or insulin concentrations during treatment.

CONCLUSION

Growth failure in these children with normal GH reserve and low serum IGF-I concentrations would suggest GH insensitivity. Supraphysiological doses of exogenous GH can cause a significant increase in serum IGF-I levels and a significant improvement in short-term growth of short children with beta-thalassaemia major.

A cross-sectional study of growth, puberty and endocrine function in patients with thalassaemia major in Hong Kong

METHODOLOGY

A cross-sectional study of growth, puberty and endocrine function was performed on 35 girls and 33 boys with thalassaemia major.

RESULTS

Despite regular transfusion and chelation therapy, 75% of the girls and 62% of the boys over the age of 12 years were below the third percentile for height. Hypogonadotropic hypogonadism was found in a similar percentage of patients. Moderate to marked zinc deficiency secondary to chelation therapy was considered unlikely because normal serum zinc levels were found in all but three of our patients, but we could not exclude the possibility of a marginal status of zinc nutrition causing growth failure. Growth hormone deficiency and diabetes mellitus were sometimes encountered but hypothyroidism, hypoparathyroidism and adrenal insufficiency were rare among our patients. Most of the patients with growth failure had normal growth hormone (GH) response to insulin induced hypoglycaemia. The serum insulin-like growth factor-1 (IGF-1) levels were low in our patients and no significant difference in the serum IGF-1 levels was found between prepubertal children with or without growth failure (0.4 +/- 0.1 mU/mL vs 0.37 +/- 0.11 mU/mL, P = 0.39). Similarly, no difference in the serum IGF-1 levels was found between pubertal children with or without growth failure (0.48 +/- 0.2 U/mL vs 0.56 +/- 0.14 U/mL, P = 0.26).

CONCLUSIONS

Delayed sexual maturation and a possible defect in growth unrelated to the GH-IGF-1 axis may be responsible for the growth failure in adolescent children with thalassaemia major.

Relationship of endocrinopathy to iron chelation status in young patients with thalassaemia major

Disturbances of growth and development in patients with thalassaemia receiving hypertransfusion programmes are well recognised and are most likely to be due to iron overload. The extent of endocrine dysfunction was investigated in a group of 18 patients thought to have been treated by acceptable modern standards, 11 of whom could be considered as well chelated. Assessment of growth and puberty showed a wide variation in height SD scores with five patients having significantly short stature. Most patients are progressing through puberty normally with the exception of two boys with marked pubertal delay. The most prominent finding was that growth hormone responses to glucagon stimulation were significantly impaired in all of the patients with iron overload. Basal endocrine assessment showed primary hypothyroidism in two patients aged 16.8 and 12.9 years with plasma thyroxine-concentrations of 86 and 59 nmol/l (normal range 65-165 nmol/l) and plasma thyroid stimulating hormone 10.2 and 30.3 mU/l (normal range 0.5-5 mU/l). One patient had diabetes mellitus. These results show that even when ideal management is sought a significant amount of endocrine damage occurs; surveillance of these patients is thus essential.

In-vitro response of erythroid progenitors from children with thalassaemia major to human growth hormone and insulin-like growth factor I

OBJECTIVE

Most short-statured children with beta-thalassaemia major have markedly reduced levels of circulating insulin-like growth factor I (IGF-I). Both human growth hormone (hGH) and IGF-I enhance the in-vitro growth of erythroid progenitors, with hGH exerting its effects via paracrine production of IGF-I. The aim of this study was to characterize further the hGH-IGF-I axis abnormalities in thalassaemia major by evaluating the erythroid potentiating effects of both peptides in cultures of thalassaemic and control erythroid progenitors.

DESIGN

Ten short-statured thalassaemic children and nine age-matched healthy donors were evaluated for the in-vitro response of their peripheral blood erythroid progenitors to stimulation with hGH and IGF-I.

MEASUREMENTS

The frequency of erythroid progenitors in serum-free cultures of thalassaemic and control peripheral blood mononuclear cells was enumerated following 14 days of incubation in the presence of hGH or IGF-I.

RESULTS

Biosynthetic hGH induced a similar dose-dependent magnitude of colony enhancement in cultures of erythroid progenitors from thalassaemic children, as compared to controls. Significant enhancement of colony growth was detected at 42 mU/l hGH, with a maximal effect detected at 83 mU/l of this hormone (173 +/- 8 vs 153 +/- 9% of baseline erythroid progenitors in patients versus controls, respectively). Enhancement of both thalassaemic and control erythroid precursors by hGH was completely abrogated by monoclonal antibodies (alpha IR-3) directed against the IGF-I membrane receptor, thereby confirming the normal capacity of thalassaemic accessory cells to produce IGF-I in response to hGH. Biosynthetic IGF-I also enhanced the growth of thalassaemic and control erythroid precursors to 172 +/- 17 and 159 +/- 10% of baseline at 100 and 10 U/l, respectively.

CONCLUSIONS

Our detection of a normal capacity of thalassaemic peripheral blood target cells to response to hGH and IGF-I suggests that these patients do not suffer from a specific defect in receptor and/or post-receptor mechanism(s) involving the response of these cells to both peptides. The normal responsiveness of thalassaemic target cells to hGH and IGF-I suggests that both peptides may be useful in the treatment of growth retardation in thalassaemia.

Cross-sectional and longitudinal study of the pituitary-thyroid axis in patients with thalassaemia major

OBJECTIVE AND DESIGN

Thyroid dysfunction is known to occur frequently in thalassaemia major, but its prevalence and severity varies in different cohorts, and the long-term natural history is poorly described. We evaluated the pituitary/thyroid axis in thalassaemia major patients in a cross-sectional study and correlated abnormalities with indices of iron overload. Furthermore, the course of thyroid disease in thalassaemia major patients was assessed in a 15-year longitudinal study.

PATIENTS AND MEASUREMENTS

Cross-sectional study: pituitary-thyroid axis function was examined in 37 patients (22 F, 15 M; aged 10-39 years, mean +/- SE = 21 +/- 1.4) out of a total of 43 who attended the Haematology and Endocrinology Clinics of Hadassah Hospital on a regular basis. The mean pretransfusion Hb level was 85 +/- 20 g/l, and all patients except one were treated with desferrioxamine (DF, mean +/- SE dose 20.2 +/- 2.6 mg/kg/day). Twenty-two had hypogonadotrophic hypogonadism (HH). Longitudinal study: 21 thalassaemia major patients were evaluated with TRH tests in 1976 and again in 1985. Fourteen of these and another eight were evaluated in both 1985 and 1991.

RESULTS

Cross-sectional study: no patient had any clinical signs or symptoms of hypothyroidism; however, one had abnormally low T4, borderline low FT4 and normal T3 levels associated with an exaggerated TSH response to TRH consistent with mild hypothyroidism. This patient did not have a previous TRH test, but serial basal determinations over 7 years revealed a progressive decrease in thyroid function. Thirty-six patients had thyroid hormone levels within the normal range. Nine of these (24.3%) had only an exaggerated TSH response to TRH whereas seven others (19%) also had borderline elevated basal TSH levels. TSH response to TRH was not correlated with age, serum ferritin or liver function tests (ALT or GGT). Longitudinal study: mean TSH response to TRH decreased (P < 0.002), and mean T3 levels increased (P < 0.001) between 1975 and 1985. These findings are probably related to the initiation of DF treatment in 1981. During the last 6 years, four patients with previously normal TSH responses to TRH developed elevated peak TSH levels. Mean T3 concentrations decreased and TSH response to TRH increased significantly (P < 0.001 for both).

CONCLUSIONS

(1) In this patient group the thyroid pituitary axis is less sensitive than the gonadal axis to iron-induced damage; only one out of 37 patients developed mild uncompensated hypothyroidism. (2) As opposed to the gonadal axis, the thyroid gland appears to fail before the central components of the axis. (3) Abnormal thyroid function may be reversible in the early stages. (4) Progression is variable, and it may take years to progress from normal to uncompensated hypothyroidism.

Evaluation of hypothalamic-pituitary function in patients with thalassemia major

The increased survival of patients with thalassemia major, made possible by more adequate therapeutic regimens, has emphasized the importance of the endocrine abnormalities often associated with this disease. In twelve thalassemic patients, we evaluated the hypothalamic-pituitary function by measuring plasma levels of anterior pituitary hormones under basal conditions and in the course of provocative tests. An impairment of growth hormone (GH) secretion was demonstrated in a considerable proportion (7/12) of these patients. In some of them failure of GH response to insulin-hypoglycemia and normal hormone rise after growth hormone-releasing hormone indicate a hypothalamic defect. A defective prolactin secretion was observed in the female hypogonadic but not in the male thalassemic patients. This abnormality appears to be dependent on estrogen deficiency rather than on a hypothalamic-pituitary dysfunction. In our series a high prevalence (8/12) of hypogonadism was also noticed. In these cases, the low gonadotropin levels and their unresponsiveness to gonadotropin-releasing hormone are compatible with a hypothalamic and/or pituitary damage. Lastly, the enhanced ACTH responses to the stimuli associated to a reduced cortisol release suggest the existence, in these patients, of a diminished adrenocortical reserve. On the whole, this study has shown several derangements of the hypothalamic-pituitary function in thalassemia. This emphasizes the need for careful endocrine surveillance in this disease.

Treatment with biosynthetic growth hormone of short thalassaemic patients with impaired growth hormone secretion

OBJECTIVE

Impairment of linear growth is a common clinical feature in patients with beta-thalassaemia major. Although growth hormone secretion appears to be normal in many short thalassaemic patients, it proves to be deficient in some of them. In these cases, administration of biosynthetic growth hormone seems justified. The aim of this study was to evaluate the effect of such treatment in a group of patients with beta-thalassaemia major presenting with growth failure and impairment of growth hormone secretion.

DESIGN

Recombinant human growth hormone, 0.6 U/kg body weight per week, given subcutaneously in three divided doses, was administered for 12 months.

PATIENTS

Eight prepubertal patients with beta-thalassaemia major, presenting with severe growth retardation and impaired growth hormone secretion in response to provocative stimuli (insulin-induced hypoglycaemia, L-dopa and growth hormone-releasing hormone), were investigated.

MEASUREMENTS

Height and pubertal stage of the patients, as well as plasma levels of insulin-like growth factor I, were determined before, during and after biosynthetic growth hormone treatment.

RESULTS

During the first 6 months of therapy, a significant increase of growth velocity was observed, from a mean pretreatment value of 2.1 +/- 0.45 cm/year to a value of 4.8 +/- 0.66 cm/year (P less than 0.002). Mean growth rate at 12 months (4.1 +/- 0.50 cm/year), though slightly decreased in comparison to that recorded at 6 months, was still significantly higher than basal (P less than 0.001). A significant increase in plasma levels of insulin-like growth factor I was recorded during treatment (2.82 +/- 0.47 vs 0.96 +/- 0.22 U/ml, P less than 0.005). No side-effects, adverse reactions or alterations in routine laboratory examinations ensued during or after therapy.

CONCLUSIONS

It appears from these data that biosynthetic growth hormone administration is worth serious consideration in patients with beta-thalassaemia major presenting growth retardation and impaired growth hormone secretion.

Growth hormone response following growth hormone releasing hormone injection in thalassemia major: influence of pubertal development

Thirty-five patients with thalassemia major, aged 7 to 21 years, were studied to define the relationship between the pubertal development and the growth-hormone (GH) secretion during sleep, after administration of GH-releasing factor (hpGRF 1-44), and betaxolol-glucagon or arginin-insulin. Pubertal development was classified as being appropriate or delayed for chronological age. GH response to pharmacological stimuli and during sleep was not linked to the pubertal development according to the chronological age. The peak of GH secretion after GHRH injection was significantly delayed in thalassemic patients with retarded puberty. The integrated secretion of GH during the 120-min test was slightly but not significantly reduced in these patients. The prepubertal pattern of GHRH response was restored in the patients receiving substitutive therapy by HCG or testosterone. The alteration of GH response to GHRH in thalassemic patients is likely to be only due to delayed puberty and decreased endogeneous GHRH secretion since it is corrected by androgen or gonadotropin replacement.

Hypogonadism in beta-thalassemic adolescents: a characteristic pituitary-gonadal impairment. The ineffectiveness of long-term iron chelation therapy

The pituitary-gonadal function was studied in 18 beta-thalassemic female adolescents, 8 with delayed puberty and 10 with primary amenorrhea,treated with repeated transfusions and long-term iron chelation therapy by subcutaneous infusion. A 100 micrograms gonadotropin-releasing hormone (GnRH) test, a double-bolus GnRH test after estradiol administration in non-responders, a 400 micrograms thyrotropin-releasing hormone (TRH) test and a 'high dose' human menopausal gonadotropin (hMG) test were performed. LH and FSH peak levels were significantly lower in thalassemic patients than in controls, both in the 100 micrograms GnRH test (LH was 4.3 +/- 0.7 mIU/ml vs 40.8 +/- 6.0 mIU/ml and FSH 3.3 +/- 0.5 mIU/ml vs 9.6 +/- 1.1 mIU/ml, respectively) and in the double-bolus GnRH test (LH was 2.3 +/- 0.2 mIU/ml vs 59.0 +/- 4.9 mIU/ml and FSH 1.8 +/- 0.3 mIU/ml vs 14.0 +/- 1.0 mIU/ml). The mean prolactin response to the TRH test was 27.8 +/- 3.2 ng/ml. After the 'high dose' hMG test 12 out of 14 admitted patients showed a poor response, lower than 250 pg/ml. Our data suggest that the hypogonadotropic condition of the thalassemic adolescents is due to pituitary hyporesponsiveness to GnRH and that most of these patients also have an impairment of ovarian function. Both conditions are a consequence of iron deposits in glands. Moreover, there is evidence that pituitary-gonadal function cannot be preserved by long-term iron chelation therapy.

Neurosecretory dysfunction of growth hormone secretion in thalassemia major

The growth retardation of children with thalassemia major is multifactorial. Along the endocrine axis of growth hormone (GH), serum somatomedin has been shown to be deficient and GH response to GH-releasing hormone impaired, while GH response to provocative stimuli is normal. We studied the spontaneous secretion of GH in seven patients with thalassemia major and growth retardation. Three of the patients were hypothyroid, and the other four were euthyroid. Spontaneous secretion of GH in all seven patients was subnormal: the number of pulses, the mean pulse amplitude, and the integrated concentration of GH were all lower than in 14 age- and sex-matched (10 pubertal and 4 prepubertal) control subjects. GH response to provocative stimuli was normal in the euthyroid patients. This pattern of response corresponds with the definition of neurosecretory dysfunction of GH secretion. It is concluded that the growth retardation of patients with thalassemia major is partly due to neurosecretory dysfunction of GH secretion.

Hematoporphyrin can inhibit the metabolism and growth of embryonic chicken cartilage in vitro

Hematoporphyrin (HP) derivatives have been recognized chiefly as growth inhibitors of neoplastic tissues within the context of tumor phototherapy. We investigated the possibility that HP may also modify the growth potential of rapidly growing nonneoplastic tissues and describe the effect of HP on the metabolism and growth of embryonic chick cartilage in vitro. In the embryonic chick pelvic rudiment prolonged organ-culture bioassay, pelvic rudiment growth was significantly inhibited when HP 0.01 mmol/L was added to the culture medium (after 5 days in organ culture, weight increment in presence of serum + 136% +/- 12% v + 90% +/- 8% in presence of serum plus HP 0.01 mmol/L and + 43% +/- 10% in presence of serum plus HP 0.025 mmol/L, P less than .001). Inhibition of cartilage growth was irreversible if HP was added to the culture medium without serum for 2 days, but partial reversibility was observed when hypophysectomized rat serum was present during that period. Therefore, the protective effect of serum was apparently unrelated to pituitary-dependent growth factors. Binding of HP to albumin did not eliminate its inhibitory effects. Uridine incorporation into RNA and, to a lesser extent, sulfate incorporation into proteoglycans were reduced in cartilage incubated overnight with HP. Our study shows that HP can exert partially reversible inhibition of cartilage metabolism and growth suggesting potentially novel tissue actions for this compound.

Results of long-term subcutaneous desferrioxamine therapy

Regular subcutaneous desferrioxamine therapy has prolonged the life and reduced the incidence of cardiac, endocrine and liver complications of iron overload in patients with thalassaemia major and other refractory transfusion-dependent anaemias. Its full impact will be apparent only when patients who began this treatment as children 10 years ago reach adult life. The major problems with s.c. DF therapy are its cost and the difficulty of patient compliance with a painful and cumbersome method of administration. Attempts to maintain normal iron stores in these patients has resulted in significant toxicity caused by the excessive use of DF. Although recent studies have shown that long-term subcutaneous calcium diethylene triamine penta-acetic acid (Ca-DTPA) can be used as an effective alternative to s.c. DF (Wonke et al, 1988), this treatment presents additional potential problems of zinc depletion which can be prevented only by careful management. The prospects of an inexpensive, orally active iron chelator are now real (Kontoghiorghes and Hoffbrand, 1988) and it is to be hoped that long-term results at least as good as those with s.c. DF will be achievable. Such oral chelators may be available to a far wider group of patients, than s.c. DF, and the problems of cost and compliance may be diminished.

Effect of human chorionic gonadotropin on growth velocity and biological growth parameters in adolescents with thalassaemia major

The effect of long-term human chorionic gonadotropin (HCG) therapy on the linear growth and biological growth parameters was studied in six thalassaemic boys aged 14.5-15.5 years old with hypogonadotropic hypogonadism. A significant (P less than 0.001) increase in growth velocity (from 3.3 +/- 0.3 to 7.6 +/- 0.6 cm/year) was found after 6-12 months of therapy, without acceleration of bone age. A striking improvement in pubertal development was observed. The treatment significantly increased growth hormone (GH) response to L-dopa administration (P less than 0.025) as well as sleep GH secretion (P less than 0.025). Serum growth factors, evaluated as thymidine activity during deep sleep, increased (P less than 0.001), but somatomedin C (Sm-C) levels did not. Prior to treatment, baseline and peak values of plasma growth hormone releasing hormone (GH-RH) following L-dopa were low. After HCG therapy, GH-RH response to L-dopa increased significantly (from 9.2 +/- 5.6 to 20.2 +/- 6.2 pg/ml; P less than 0.05), but remained (P less than 0.001) lower than in normal prepubertal children. This study suggests that in thalassaemia major an impaired GH-RH release can be observed, in addition to the described alteration in Sm-C generation.