Comparison of two immunoassays in the determination of IGF-I levels and its correlation with oral glucose tolerance test (OGTT) and with clinical symptoms in acromegalic patients.

The aim of our study was to evaluate two different methodologies in IGF-I levels determination, its correlation with GH nadir in OGTT <1 and <0.4 ng/ml and with clinical symptoms in acromegalic patients. We analyzed 37 patients. Sixteen patients had not undergone any kind of treatment (Group 1). Twenty-one patients underwent surgery as primary treatment, and after that, some of them another kind of treatment (except pegvisomant) (Group 2). Serum IGF-I levels were measured by Immulite-1000 (IMM) and by an immunoradiometric assay (DSL) and, GH by immunochemiluminometric assay. IGF-I levels by IMM and by DSL showed a significant difference. When we analyzed in both groups the concordance by crosstabs-Kappa coefficients, between different parameters, GH nadir <1 and <0.4 ng/ml with IGF-I by DSL and IMM showed concordance in group 1, but in group 2 only GH nadir <1 and <0.4 ng/ml had a weak concordance with IGF-I by IMM. When we analyzed clinical symptoms in the patients and, GH nadir <1 and <0.4 ng/ml and IGF-I levels by both methodologies, more than 90% of clinically active patients had abnormal GH response or/and elevated IGF-I levels in group 1, but less than 70% in group 2. In the 8 patients under medical treatment, GH nadir was higher than 0.4 ng/ml in all patients, and IGF-I levels were elevated in 8/8 by DSL and in 6/8 by IMM. In conclusion, discrepant GH and IGF-I levels in the diagnosis and follow-up of patients with acromegaly requires consideration of many factors that influence these parameters.

Enanismo asociado a panhipopituitarismo con neurohipófisis ectópica, sin diabetes insípida / Dwarfism associated at panhypopituitarism with ectopic neurohypophysis without diabetes insipidus

We are introducing a patient of 22 years old who suffers from Dwarfness and primary Amenorrhea. She showed dosages of basal somatotrophin and post estimulation of 0.5 ng/ml or less, somatomedin (IGF1): 2.40 ui/ml, rudiment uterus and annexes with normal karyotype 46xx. RMN of Sella Turcica and adjacencies showed; a posterior pituitary lobe ectopy, with the conservation of his hypothalamic conexion and hormonal deficit of L.A. (suprarenal, gonadal and somatotrophic axes). The use of RMN allowed us to evaluate and thus reached a precise diagnosis in reference to the hypothalamic lesion.