Urinary aHGF, IGFBP3 and OPN as diagnostic and prognostic biomarkers for prostate cancer.

AIM: Serum PSA screening for prostate cancer (PCa) is controversial. Here, we identify three urinary biomarkers - aHGF, IGFBP3 and OPN - for PCa screening and prognostication. METHODS: Urinary aHGF, OPN and IGFBP3 from healthy men (n = 19) and men with localized (n = 65) and metastatic (n = 36) PCa were quantified via ELISA. Mann-Whitney nonparametric t-test and the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analyses were used to analyze associations. RESULTS: Mean aHGF and IGFBP3 levels were significantly elevated in PCa patients versus controls (p = 0.0006 and p = 0.0012, respectively), and the area under the curve of the receiver operating characteristic curve (indicator of diagnostic accuracy) for aHGF and IGFBP3 was 0.75 and 0.74, respectively. OPN levels were significantly higher in metastatic groups (p = 0.0060) versus localized and controls (area under the curve = 0.68). CONCLUSION: Urinary aHGF and IGFBP3 exhibit the capacity for diagnostic discrimination for PCa, whereas OPN may indicate presence of metastatic disease.

Urinary excretion of IGFBP-1 and -3 correlates with disease activity and differentiates focal segmental glomerulosclerosis and minimal change disease.

The glomerular microenvironment is influenced by circulating growth factors that are filtered from the blood stream and pass the glomerular filtration barrier. In this study, we wanted to explore the role of IGF-binding proteins (IGFBPs) in two diseases that concern podocytes. We analyzed glomerular expression and urinary excretion of IGFBP-1, -2, and -3 in patients with focal segmental glomerulosclerosis (FSGS) or minimal change disease (MCD). We found that patients with active FSGS excrete high amounts of podocalyxin positive cells as well as IGFBP-1 and -3. In human podocytes, we can induce mRNA expression of IGFBP-3 in response to TGF-beta and in human microvascular endothelial cells expression of IGFBP-1 and -3 in response to TGF-beta and Bradykinin. We conclude that the local expression of IGFBPs in podocytes and endothelial cells might contribute to the pathogenesis of glomerular disease and that IGFBP-1 and -3 are potential non-invasive markers of FSGS.

Growth hormone treatment improves markers of systemic nitric oxide bioavailability via insulin-like growth factor-I.

CONTEXT AND OBJECTIVE: Impaired nitric oxide (NO) bioavailability and low levels of circulating endothelial progenitor cells (EPC) are correlated to an increased risk for development of cardiovascular diseases. We investigated whether improved systemic NO bioavailability and increased levels of EPC after GH treatment are related and mediated by the IGF-I. DESIGN, PATIENTS, AND RESULTS: Healthy middle-aged volunteers (n = 16) were treated for 10 d with recombinant human GH. Before and after GH treatment, we analyzed markers of NO bioavailability and EPC levels. GH treatment was responded by significant increases in plasma IGF-I levels. Urinary cGMP levels were increased and diastolic blood pressure reduced after GH treatment (P < 0.05). Likewise, plasma nitrate and nitrite levels were increased, whereas the NO synthase inhibitor asymmetric dimethylarginine was reduced. Correspondingly, IGF-I treatment increased expression of the asymmetric dimethylarginine-metabolizing enzyme dimethylarginie dimethylaminohydrolase-1 and dimethylarginie dimethylaminohydrolase-2 in cultured human endothelial cells. IGF-I levels correlated with cGMP concentrations (r = 0.51; P < 0.05). EPC numbers were increased after GH treatment and correlated with markers for NO bioavailability. These findings were also observed in mice treated with GH for 7 d. GH treatment additionally increased aortic endothelial NO synthase expression of mice. Importantly, blocking of the IGF-I receptor in vivo abolished the GH-mediated effects on markers of increased NO bioavailability. CONCLUSIONS: GH treatment induced markers of increased NO bioavailability and enhanced circulating EPC numbers in healthy volunteers. Animal data demonstrate increased NO availability to be mediated via an increase in IGF-I plasma levels. Thus, GH treatment enhances systemic NO bioavailability via IGF-I and may be beneficial in certain cardiovascular diseases.

Influence of acute exercise on urinary protein, creatinine, insulin-like growth factor-I (IGF-I) and IGF binding protein-3 concentrations in children.

Insulin-like growth factor-I (IGF-I) is a polypeptide hormone and present in human urine. Insulin-like growth factor binding protein-3 (IGFBP-3) is the major form of binding protein in human circulation and functions as a carrier for IGF-I. Our goal was to determine the effects of volleyball exercise on the concentrations of urine protein, creatinine, IGF-I, and IGFBP-3 in children and to find out whether these effects differ between boys and girls. Volunteer children (13 females and 14 males), aged 10-13 years old were included in this work. Weight and height of the subjects were measured, and urine samples of their were collected before and after 2 hours of exercise. Urinary protein, creatinine, IGF-I and IGFBP-3 levels were analysed. Urinary protein, creatinine and IGF-I concentrations were increased after two hours of exercise wheres urinary IGFBP-3 concentrations did not change. In addition, no statistically significant difference in all parameters analysed was observed between boys and girls of similar age and body mass index.

IGFs and IGF-binding proteins in short children with steroid-dependent nephrotic syndrome on chronic glucocorticoids: changes with 1 year exogenous GH.

OBJECTIVE: Children with steroid-dependent nephrotic syndrome (SDNS), despite being in remission on glucocorticoids, continue to have growth retardation and short stature. The mechanism is uncertain as both chronic glucocorticosteroids and the nephrotic syndrome may independently affect growth. We investigated the changes in the IGFs and IGF-binding proteins (IGFBPs) in a group of short SDNS children, and studied the changes prospectively with 1 year's treatment with GH. DESIGN AND METHODS: Total and 'free' IGF-I, IGFBP-3 and acid-labile subunit (ALS) were studied in eight SDNS boys (mean age=12.6 years; mean bone age=9.1 years) on long term oral prednisolone (mean dose 0.46 mg/kg per day) before, during, and after, 1 year's treatment with GH (mean dose 0.32 mg/kg per week). Pretreatment comparisons were made with two control groups, one matched for bone age (CBA; mean bone age=9.2 years), and another for chronological age (CCA; mean chronological age=13 years). Subsequently, three monthly measurements of serum and urine IGFBPs were carried out in the GH-treated SDNS patients using Western ligand blot and Western immunoblot. RESULTS: Pre-treatment serum total IGF-I levels and the IGF-I/IGFBP-3 ratio were elevated significantly in SDNS compared with CBA, and were similar to CCA. Serum free IGF-I levels were elevated significantly compared with both control groups, but serum IGFBP-3 did not differ significantly. Urinary IGFBP-2, IGFBP-3 and ALS were detectable in the SDNS children only. With GH treatment, IGF-I and IGFBP-3, but not IGF-II, increased significantly compared with pre-treatment values, and returned to baseline after cessation of GH treatment. Urinary IGFBPs did not change significantly with GH treatment. CONCLUSIONS: There is persistent urinary loss of IGFBP-2, IGFBP-3 and ALS in children with SDNS in remission with growth retardation. However, the significant elevation in serum IGF-I suggests that glucocorticoid-induced resistance to IGF is the main factor responsible for the persistent growth retardation in these children. Exogenous GH was able to overcome this resistance by further increasing serum IGF-I.

Proteolysis of insulin-like growth factor-binding protein-3 is increased in urine from patients with diabetic nephropathy.

The insulin-like growth factor (IGF) system has been implicated in the development of experimental diabetic nephropathy. IGF-binding protein-3 (IGFBP-3) modulates IGF actions, and proteolysis decreases its binding affinity for IGFs. The aim of this study was to explore the possibility that proteolysis of IGFBP-3 may be altered in diabetic nephropathy and may therefore modify the intrarenal effects of IGFs. IGFBP-3 proteolysis in urine from diabetic patients with normo- [albumin excretion rate (AER), <20 microg/min], micro- (AER, 20-200 microg/min), and macroalbuminuria (AER, >200 microg/min) was studied in 34 patients with noninsulin-dependent diabetes mellitus (NIDDM), 14 patients with insulin-dependent diabetes mellitus, and 9 controls. Urine samples were analyzed by Western ligand blotting and IGFBP-3 immunoblotting. Protease activity was quantitated using [125I]IGFBP-3 as a substrate. WLB showed three main bands (40-46, 35, and 26 kDa) in control urine and a fainter 18-kDa band. All but the 35-kDa band were immunoreactive with the IGFBP-3 antiserum. The same pattern of IGFBPs was seen in urine from normoalbuminuric diabetic patients. However, the urine of diabetic patients with micro- and macroalbuminuria contained little or no intact 40- to 46-kDa IGFBP-3. In patients with noninsulin-dependent diabetes mellitus, urinary IGFBP-3 protease activity in micro- (n = 13) and macroalbuminuric patients (n = 12; mean +/- SD[SCAP], 75 +/- 25% and 84 +/- 24%) was significantly higher than that in normoalbuminuric patients (29 +/- 9%; P = 0.0001). Similar results were observed in patients with insulin-dependent diabetes mellitus. Proteolytic activity in diabetic urine was due to a serine protease. In conclusion, diabetic nephropathy was associated with IGFBP-3 proteolysis in urine. As similar changes were not observed in patients' sera, this is likely to reflect changes in the kidney or urinary tract, resulting in increased local IGF bioavailability, and therefore may contribute to the structural changes of diabetic nephropathy.

Evaluation of the components of insulin-like growth factor (IGF)-IGF binding protein (IGFBP) system in adolescents with type 1 diabetes and persistent microalbuminuria: relationship with increased urinary excretion of IGFBP-3 18 kD N-terminal fragment.

OBJECTIVE: IGFs and their binding proteins (IGFBPs) have an important role in controlling glucose homeostasis and there is evidence to support their involvement in complications related to type I diabetes. The aim of this study was to evaluate the components of the IGF-IGFBP system in adolescents with type 1 diabetes that had developed persistent microalbuminuria (MA). DESIGN AND PATIENTS: A cohort of 49 adolescents with type 1 diabetes were enrolled in the study. Patients were evaluated at baseline and 1 year later (follow-up). Twenty-six patients with persistent urinary albumin excretion (UAE) of more than 20 microg/min/1.73 m2 (21.6-109. 4 microg/min/1.73 m2) in three different nocturnal urinary collections within 6 months were considered to have MA (baseline mean: 41.9 +/- 22.3 microg/min/1.73 m2; follow-up: 55.9 +/- 24.8 microg/min/1.73 m2). Twenty-three patients with UAE of less than 20 microg/min/1.73 m2 were assigned to the group without MA (baseline mean: 8.6 +/- 3.7 microg/min/1.73 m2; follow-up: 11.8 +/- 4.2 microg/min/1.73 m2). Fasting serum levels of IGFBP-1, IGFBP-2, IGFBP-3, IGF-I and free-IGF-I were determined using appropriate immunoenzymatic, radioimmuno- or immunoradiometric assays. Overnight 12-h urinary collections were obtained and assessed for IGFBP-3 levels, determined by immunoradiometric assay. Urinary and circulating immunoreactive IGFBP-3 forms were determined by Western-immunoblotting (WIB) analysis using a specific polyclonal antibody and monoclonal antibodies directed against N-terminal and C-terminal epitopes of IGFBP-3. IGFBP-3 protease activity was determined using protease assay and by analysis of the intact over the fragmented immunoreactive forms of IGFBP-3 determined by WIB analysis. RESULTS: Patients with MA showed higher levels of urinary IGFBP-3 (649 +/- 440 ng/h/m2) than patients without MA (398 +/- 229 ng/h/m2; P < 0.05). Urinary levels of IGFBP-3 were directly correlated to UAE (P < 0.001). WIB analysis, using monoclonal antibodies directed against characterized N-terminal and C-terminal IGFBP-3 epitopes, determined that the immunoreactive form of IGFBP-3 found in urine from patients with diabetes was an N-terminal 18 kD fragment. Serum IGFBP-3 levels were lower in patients with MA (baseline: 3613 +/- 598 microg/l; one year follow-up: 3347 +/- 624 microg/l) compared with patients without MA (baseline: 4701 +/- 1484 microg/l; follow-up: 4177 +/- 703 microg/l; P < 0.001). In serum from patients with MA, intact IGFBP-3 was decreased, as indicated by WIB analysis. Conversely, IGFBP-3 proteolysis was increased in patients with MA (baseline: 131 +/- 21% of control; follow-up: 130 +/- 23% of control), compared to patients with normal UAE (baseline: 96 +/- 23% of control; follow-up: 96 +/- 14% of control; P < 0.001). Serum IGFBP-3 protease activity was directly correlated to urinary IGFBP-3 levels (P < 0.001). Serum IGFBP-1 levels were increased in patients with MA (baseline: 36 +/- 20 microg/l; follow-up: 36 +/- 17 microg/l) compared with patients without MA (baseline: 17 +/- 11 microg/l; follow-up: 18 +/- microg/l; P < 0.05). Serum IGFBP-2 levels were also persistently increased in patients with MA (baseline: 503 +/- 134 microg/l; follow-up: 484 +/- 166 microg/l) compared with patients without MA (baseline: 375 +/- 83 microg/l; follow-up: 390 +/- 85 microg/l; P < 0.05). On the other hand, free IGF-I levels were decreased in patients with MA (baseline: 2.3 +/- 1. 5 microg/l; follow-up: 2.5 +/- 1. (ABSTRACT TRUNCATED)

Urinary growth hormone (GH), insulin-like growth factor I (IGF-I), and IGF-binding protein-3 measurements in the diagnosis of adult GH deficiency.

The diagnosis of GH deficiency (GHD) in the elderly is based at present on the peak GH concentration during a stimulation test. We have now evaluated the performance of urinary GH (uGH), urinary insulin-like growth factor I (uIGF-I), and urinary IGF-binding protein-3 (uIGFBP-3) in the diagnosis of GHD in this group. Twenty GHD elderly patients with a history of pituitary disease and a peak GH response to arginine stimulation of less than 3 ng/mL (15 men and 5 women; age, 61.1-83.4 yr) and 19 controls (12 men and 7 women; age, 60.8-87.5 yr) were studied. GH secretion was assessed by 24-h profile and expressed as the area under the curve (AUCGH). Serum (s) IGF-I and sIGFBP-3 were measured in a single morning, fasted sample. Urinary GH, uIGF-I, and uIGFBP-3 were measured in a 24-h urine sample collected over the same interval as the GH profile, and results were expressed as total amount excreted in 24 h (tuGH24, nanograms; tuIGF-I24, nanograms; tuIGFBP-3(24), micrograms). Data are presented as the mean +/- SD, except for AUCGH, tuGH24, and tuIGFBP-3(24), which are presented as the geometric mean (-1, +1 tolerance factor). AUCGH, sIGF-I, and sIGFBP-3 were significantly lower in GHD subjects than in controls. Total uGH24 was lower in GHD subjects, but tuIGF-I24 and tuIGFBP-3(24) excretion were not different in the two groups. AUCGH provided the best separation between GHD and control subjects, whereas there was substantial overlap for sIGF-I, sIGFBP-3, and tuGH24. In both groups sIGF-I was correlated to sIGFBP-3 (GHD, r = 0.75; controls, r = 0.65; both P < 0.01), whereas tuIGF-I24 was not correlated to tuIGFBP-3(24) in either group. Moreover, tuIGF-I24 and tuIGFBP-3(24) were not related to their respective serum concentrations in either group. Total uGH24 was correlated with AUCGH only in controls (r = 0.54; P < 0.05). These data demonstrate that urinary GH and urinary and serum IGF-I and IGFBP-3 are not suitable diagnostic markers for GHD in elderly subjects.

Insulin and IGF binding by IGFBP-3 fragments derived from proteolysis, baculovirus expression and normal human urine.

Recombinant human IGFBP-3 was proteolysed with different concentrations of plasmin for various periods of time. The major IGFBP-3 fragment resulting from this digestion migrated at ca. 15 kDa in nonreducing SDS-PAGE. Following the identification of this fragment as an N-terminal IGFBP-3 fragment, by use of N-terminus-specific monoclonal antibody and amino acid sequence analysis, we constructed and expressed a similar fragment in a baculovirus expression system. The fragments resulting from plasmin digestion, as well as the baculovirus-expressed recombinant human IGFBP-3(1-97), retain weak IGF binding and show specific insulin binding on cross-linking and western ligand blot. RhIGFBP-3(1-97) can inhibit insulin receptor autophosphorylation in insulin receptor-overexpressing NIH 3T3 cells. Insulin and IGF binding to IGFBP-3 fragments could be further demonstrated in normal urine. These data indicate the physiological significance of IGFBP-3 fragments derived from proteolysis in vivo.

Urinary growth hormone excretion in post-menarcheal adolescent girls with type 1 diabetes.

The aim of the present study was to compare measurements of urinary growth hormone (GH), serum insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP3) between two groups of post-menarcheal girls, 13-18 y of age, one comprising 64 type 1 diabetic patients and the other 64 healthy girls matched for age and stage of puberty. GH was determined on two occasions in nocturnal urine samples by using a modification of an immunoradiometric method for serum. Significantly higher urinary GH concentrations but lower IGF-I and IGFBP3 levels were found in diabetic girls than in controls (p < 0.001). A significant correlation was found between urinary GH concentrations and the daily dose of insulin (U kg[-1]) (r = 0.426, p = 0.003). Urinary GH concentrations were also significantly related to HbA1c (r = 0.380, p = 0.003). In conclusion, disturbances of the GH-IGF-I axis may be evaluated by the use of non-invasive urinary GH measurements, which is a simple alternative to frequent sampling of serum GH. Increased GH secretion seems to be related to a great need for insulin and poor metabolic control. More knowledge about underlying causal factors in the disturbed GH-IGF-I axis is required.

Concentrations of specific epithelial growth factors in the urine of interstitial cystitis patients and controls.

PURPOSE: Interstitial cystitis (IC) is a chronic bladder disease for which the etiology is unknown. Because the bladder epithelium is often abnormal in IC, we determined whether the levels of specific urine growth factors postulated to be important for bladder epithelial proliferation are altered in IC. MATERIALS AND METHODS: ELISAs were used to determine levels of epidermal growth factor (EGF), insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3), and heparin binding epidermal growth factor-like growth factor (HB-EGF) in urine specimens from women with IC, asymptomatic women without bladder disease, and women with bacterial cystitis. RESULTS: Urine HB-EGF levels were specifically and significantly decreased in IC patients as compared to asymptomatic controls or patients with bacterial cystitis, whether expressed as concentration (amount per volume of urine) or the amount relative to urine creatinine in each specimen. In contrast, urine EGF, IGF1, and IGFBP3 levels were all significantly elevated in IC patients compared to asymptomatic controls. Further, the amounts of urine EGF and IGF1 were also elevated in IC patients as compared to patients with bacterial cystitis, and urine IGFBP3 levels were significantly elevated when expressed per milligram of urine creatinine. CONCLUSIONS: These findings indicate that complex changes in the levels of urine epithelial cell growth factors (EGF, IGF1, and HB-EGF) and a growth factor binding protein (IGFBP3) are associated with IC. While EGF, IGF1, and IGFBP3 levels are either the same or increased in the urine of IC patients as compared to patients with bacterial cystitis or asymptomatic controls, HB-EGF levels are significantly decreased in the urine of IC patients. Understanding the reasons for these changes may lead to understanding the pathogenesis of this disorder.

A comparison of different methods for diagnosing acromegaly.

OBJECTIVE: The present study was designed to assess the diagnostic value of different single measurements in comparison to the classic time-consuming method, the oral glucose tolerance test (OGTT), in acromegaly. DESIGN, PATIENTS AND MEASUREMENTS: IGF-I, free IGF-I, 24-hour-urinary GH (uGH), serum IGFBP-3 and 24-hour-urinary IGFBP-3 (uIGFBP-3) were measured in 12 patients with untreated active acromegaly, in 29 patients who had been treated but were not cured, in 13 patients with cured acromegaly and in 14 healthy control subjects, and compared with the results of the OGTT. RESULTS: In all patients with active acromegaly, whether they had been treated or not, nadir GH in OGTT was > 3 mU/l, whereas nadir GH was < 1.8 mU/l in the cured patients and the control subjects. In patients with untreated active acromegaly IGF-I, free IGF-I, uGH and IGFBP-3, but not uIGFBP-3, were significantly higher than in healthy individuals (P < 0.0001). Only IGF-I values did not overlap with the control group. In those patients with acromegaly who had been treated but not cured these parameters overlapped with the control group. In patients with acromegaly there was a significant correlation between nadir GH levels in OGTT and IGF-I (r = 0.71), free IGF-I (r = 0.76), IGFBP-3 (t = 0.73) and uGH (r = 0.81) (P < 0.0001), but no correlation with uIGFBP-3. CONCLUSIONS: Only be means of the OGTT could patients with active acromegaly be completely distinguished from the control subjects and from cured patients. IGF-I, free IGF-I, IGFBP-3 and uGH were useful in the diagnosis of acromegaly, but of limited value in the follow-up of acromegalic patients after treatment. The determination of free IGF-I, which has yet not been investigated in acromegaly, offered no advantage over that of total IGF-I and IGFBP-3; uIGFBP-3 was not useful in the diagnosis of acromegaly.

Urinary IGF and IGF binding protein-3 in children with disordered growth. The North West Paediatric Endocrine Group.

OBJECTIVE: Both IGF-I and IGFBP-3 reflect spontaneous GH secretion in healthy individuals. We have evaluated the clinical usefulness of urinary IGF-I and IGFBP-3 measurements in the diagnosis of children with disordered growth. DESIGN: Serum IGF-I and IGFBP-3 radioimmunoassays (RIA) were developed, and modified for quantitation in urine. The relationship between serum and urine levels, and the performance of these tests in the diagnosis of GH deficiency (GHD) were examined. PATIENTS: Sixty-nine children (age 9.5 +/- 3.6 years; 37 boys, 32 girls) provided a timed overnight urine collection and a serum sample collected on the same morning. Subjects were defined as GHD (n = 22) or short normal (SN; n = 47) on the basis of medical history, clinical examination, auxology and peak response to a GH stimulation test (< 20 mU/L in GHD patients). MEASUREMENTS: IGF-I and IGFBP-3 in serum and urine were measured by RIA, urinary GH (uGH) by immunoradiometric assay (IRMA) after dialysis and urinary creatinine by the alkaline picrate method. Urine results were expressed as total amount excreted (tulGFBP-3 (microgram), tulGF-1 (ng), tuGH (ng), tuCrt (mmol). RESULTS: Urine IGF-I and IGFBP-3 excretion correlated significantly to serum levels of IGF-I and IGFBP-3 and also to tuGH excretion. There was a strong positive relationship between both urinary peptides and tuCrt, which suggested that renal filtration was the source of these peptides in urine. In addition, there were significant correlations with age, bone age and height SD score, of similar magnitude to those for tuGH. In prepubertal children, serum IGF-I and IGFBP-3 were significantly lower in GHD compared with SN children, while in puberty only serum IGFBP-3 was significantly lower in GHD. There was no difference however, in tulGF-I or tulGFBP-3 between GHD and SN children either prepubertally or in puberty with near complete overlap of the values between groups. CONCLUSIONS: Measurements of tulGF-I and tulGFBP-3 have no place in the diagnosis of childhood GHD. Nonetheless, the significant correlations between serum and urinary IGF-I and IGFBP-3 levels and their correlation to uGH indicate that these peptides could be used as non-invasive physiological markers of the GH-IGF axis.

Extracorporeal losses of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in adult patients on CAPD.

The effects of extracorporeal (urinary plus peritoneal) losses of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) on their respective serum levels were studied in 10 adult patients (aged 42-74 years) with end-stage renal failure and residual renal function of 0-4.5 mL/min. All patients had been on continuous ambulatory peritoneal dialysis (CAPD) for a period of 2-27 months. Morning serum, 24-hour urine, and 8-hour overnight peritoneal concentrations of IGF-I and IGFBP-3 were measured by radioimmuno- (Incstar) and immunoradiometric (Active) assays. CAPD patients showed extracorporeal losses (mean +/- SEM) of 118.7 +/- 10.6 micrograms (urinary 6.4 +/- 2.8 and peritoneal 112.3 +/- 8.5 micrograms) of IGF-I/24 hour and 1.5 +/- 0.1 mg (urinary 0.2 +/- 0.1 mg and peritoneal 1.3 +/- 0.1 mg) of IGFBP-3/24 hour. Extracorporeal losses of IGF-I accounted for about 4% of the daily production rate of this polypeptide, and the peritoneal and urinary concentrations of IGFBP-3 did not exceed 4% and 14%, respectively, of their serum levels. Serum concentrations of IGF-I (227.7 +/- 64.2 micrograms/L) and IGFBP-3 (5.3 +/- 2.4 mg/L) were not significantly correlated with extracorporeal, peritoneal, or urinary losses of these proteins or with residual renal function. We suggest that extracorporeal losses of IGF-I and IGFBP-3 in adult patients on CAPD do not influence their serum levels and that IGF-I may therefore be used as a marker of malnutrition.

Detection of human growth hormone doping in urine: out of competition tests are necessary.

The misuse of human growth hormone (hGH) in sport is deemed to be unethical and dangerous because of various adverse effects. Thus, it has been added to the International Olympic Committee list of banned substances. Until now, the very low concentration of hGH in the urine made its measurement difficult using classical methodology. Indeed, for routine diagnosis, only plasma measurements were available. However, unlike blood samples, urine is generally provided in abundant quantities and is, at present, the only body fluid allowed to be analysed in sport doping controls. A recently developed enzyme-linked immunosorbent assay (Norditest) makes it now possible, without any extraction, to measure urinary hGH (u-hGH) in a dynamic range of 2-50 ng hGH/l. In our protocol, untreated and treated non-athlete volunteers were followed. Some of them received therapeutical doses of recombinant hGH (Norditropin) for one week either intramuscularly (three increasing doses) or subcutaneously (12 i.u. every day). The u-hGH excretion after treatment showed dramatic increases of 50-100 times the basal values and returned to almost the mean normal level after 24 h. u-hGH was also measured in samples provided by the anti-doping controls at major and minor competitions. Depending on the type of efforts made during the competition, the hGH concentration in urine was dramatically increased. Insulin-like growth factor binding proteins and beta 2-microglobulins in urine and/or in blood could be necessary for the correct investigation of any hGH doping test procedure.

Characterization of a low molecular mass form of insulin-like growth factor binding protein-3 (17.7 kilodaltons) in urine and serum from healthy children and growth hormone (GH)-deficient patients: relationship with GH therapy.

The insulin-like growth factor binding proteins (IGFBPs) are the carriers for insulin-like growth factor (IGF0-I and IGF-II. IGFBP-3 is GH-dependent and circulates associated with IGFs and an acid-labile subunit to form a 150-kilodalton (kDa) complex. In human serum, two immunoreactive molecular weight forms of IGFBP-3 have been identified. In human urine, radioimmunoassayable levels of IGFBP-3 have been detected. The objectives of this study were to characterize the molecular weight forms of IGFBP-3 in urine and serum of healthy children and adults and in children with GH deficiency (GHD), to quantify the urinary molecular weight forms of IGFBP-3, and to evaluate the relationship of these forms with GH therapy. Urine and serum were obtained from 12 prepubertal children with GHD, before and after 6 months of GH therapy, from 30 prepubertal healthy children, and from 8 healthy adults. Western immunoblotting (WIB) with IGFBP-3 antiserum (alpha IG-FBP-3g1) showed that in urine the most representative IGFBP-3 was a 17.7-kDa form. The 17.7-kDa IGFBP-3 was high in urine of healthy children compared with healthy adults and was low in children with GHD but increased after GH therapy. Urinary IGFBP-3 immunoreactive profile was determined by neutral-size exclusion chromatography, followed by IGFBP-3 RIA analysis of the fractions. Urine showed a major peak of IGFBP-3 immunoreactivity around 17 kDa. The 17-kDa urinary IGFBP-3 chromatographic peak averaged 8461 +/- 367 ng/12 h.m2 of body surface in healthy children, 3415 +/- 739 in adults (P < 0.001), 2294 +/- 354 in children with GHD before GH therapy (P < 0.001), and 7940 +/- 1874 in children with GHD after GH therapy. Urinary IGFBP-3 was also measured by RIA in unfractionated urine; healthy children showed levels significantly higher (14575 +/- 460 ng/12 h.m2) than adults (7823 +/- 1083, P < 0.001) and higher than children with GHD before GH therapy (4710 +/- 703, P < 0.001). Again, however, immunoreactive IGFBP-3 increased after GH treatment (12294 +/- 3394). In the serum of the healthy children we characterized by specific IGFBP-3 WIB analysis, a 17.7-kDa immunoreactive form of IGFBP-3 that was absent in the serum of healthy adults and low in patients with GHD, increased during GH therapy. Serum samples were subjected to neutral-size exclusion chromatography and the fractions were analyzed by WIB.(ABSTRACT TRUNCATED AT 400 WORDS)

Fetal urinary insulin-like growth factor I and binding protein 3 in bilateral obstructive uropathies.

Fetal urinary concentrations of insulin-like growth factor I (UIGF-I) and binding protein 3 (UIGFBP-3) were determined in patients with prenatal diagnosis of bilateral obstructive uropathy. Patients were retrospectively assigned to three groups, on the basis of outcome: group 1, termination of pregnancies (n = 11) with sonographic evidence of severe oligohydramnios or renal dysplasia, confirmed at histological examination; group 2, patients (n = 10) with postnatal plasma creatinine > 50 mumol/l at the age of 1 year (1 yr-pCreat); and group 3, patients (n = 16) with 1 yr-pCreat < or = mumol/l. The results show a significant increase in UIGF-I and UIGFBP-3 in groups 1 (18,159 +/- 9083 pg/ml; 2657 +/- 669 ng/ml) and 2 (1574 +/- 847 pg/ml; 176 +/- 50 ng/ml) in comparison with group 3 (35 +/- 6 pg/ml; 21 +/- 2 ng/ml). UIGF-I and UIGFBP-3 were significantly correlated with postnatal plasma creatinine, and were both sensitive (90 per cent; 80 per cent) and specific (88 per cent; 88 per cent) for prediction of elevated 1 yr-pCreat (> 50 mumol/l). Fetal urinary IGF-I and IGFBP-3 are increased in severe fetal bilateral obstructive uropathy, possibly reflecting tubular dysfunction or/and increased synthesis consequent upon fetal kidney injury. Their predictive value for postnatal renal function needs further assessment.