ABSTRACT
Objective To investigate the interference of thyroglobulin antibodies ( TgAb ) on the measurement of thyroglobulin ( Tg) by 2 chemiluminescence immunoassays ( CLIAs) .Methods Data of 199 315 individuals with determined TgAb and Tg , including physical checkup subjects , differentiated thyroid carcinoma ( DTC) patients and patients with other diseases , were retrospectively collected in Peking Union Medical College Hospital from November 2012 to April 2015.The correlation between serum Tg level and serum TgAb concentration was analyzed and the positive rate of TgAb in physical checkup subjects was calculated.Furthermore, 290 serum samples with different TgAb concentration were applied in the recovery test by adding in confirmed serum Tg .The correlation between the recovery of confirmed serum Tg and TgAb concentrations was evaluated using Pearson correlation analysis .Results The serum Tg was all decreased with the elevated TgAb concentration in each group of subjects .The positive rate of TgAb was 10.84%(8 416/77 634) in physical checkup subjects .It was higher in females than in males and was increased with age.Recovery test showed that the average recoveries of confirmed serum Tg in TgAb-negative serum were 107.28%(86.30%-117.60%) and 107.94% (85.60%-124.10%) respectively in Roche and Beckman systems.But in TgAb-positive serum samples , the average recoveries in Roche and Beckman systems were 88.59% (35.85% -141.53%) and 95.77% (36.48% -131.78%) respectively, and 12.63%(24/190) and 13.68%(26/190) samples displayed a recovery less than 80%.The recovery rate of confirmed serum Tg showed a significantly negative correlation with elevated TgAb concentration , with r=-0.239 (P=0.001) in Roche and r=-0.251 (P<0.001) in Beckman.Conclusions TgAb-positive serum, especially with high concentration of TgAb , significantly interfered the measurement of Tg .Thus, serum TgAb should be determined together with serum Tg to explore whether there was an interference .To avoid misdiagnosis and inappropriate therapy , clinician should be informed once serum TgAb displayed positive.
ABSTRACT
Objective To clarify the possible gene mutations in luteinizing hormone(LH) receptor gene in a boy with LH independent precocious puberty and probe the mechanism the of diseases caused by LH receptor activating mutations. Methods ( 1 ) Describe the clinical manifestations and laboratory data in a 5-year-old boy with LH independent precocious puberty. (2) Peripheral leukocytes were collected from the proband, his parents and other 20 normal puberty developed males. PCR and direct DNA sequence of 11 exons in LH receptors gene were conducted. Results (1) The proband was diagnosed to have LH independent precocious puberty according to the clinical symptoms and the laboratory tests. (2) A germ-line heterozygous point mutation in the 11 exon of LH receptor gene was found in the proband and his mother:c1193 T→C leading to amino acid change with M398T, which causes consecutively an activation of the LH receptor. (3) Other nucleotide changes in the proband and other normal males include c935 A→ G (N312S) and c1065 T→C(same sense mutation). Conclusions (1) A germ-line heterozygous point mutation in the LH receptor gene with M398T leads to consecutively activation of the LH receptor and LH independent precocious puberty. (2) The same point mutation does not have any influence on the puberty development, menstruation and productive functions of the proband's mother. (3) The LH receptor gene has possible polymorphism in the Han ethnic population.
ABSTRACT
Objective To analyse the clinical significance of LHRH exciting test in the differential diagnosis of constitutional delayed puberty (CDP) and hypogonadotropic hypogonadism (HH). Methods Eighty-one cases from 1982 to 1998 were investigated and followed up. They were all at genital stage Ⅰ. After injection of 100 ?g LHRH, the blood samples (3 ml) were taken at -15, 0, 15, 30, 45, 60, 90 and 120 min. The serum LH and FSH levels were determined by radioimmunoassay. Then they were followed up every 3-24 months. After they received LHRH exciting test, they were followed up until over 18 years old. According to their puberty development status, they were divided into 3 groups, normal group (n=34),CDP group (n=16) and HH group (n=31),andthemeanage,whenthey received LHRH exciting test, was (10.2?0.9, range 9-14) years, (16.0?1.0, range 14-18) years and (17.1?1.4, range 16-22) years respectively. Results There were no significant differences in serum LH baseline level and peak time in normal, CDP and HH groups, but the serum LH peak level, LH increment (peak LH level minus baseline LH level), LH increment ratio (peak level/baseline level of LH) and the area under LH curve (AUC LH ) of normal group were significantly higher than those of CDP group and HH group (all P