RESUMO
Background: Malabsorption of levothyroxine (LT4) is a common problem faced in clinical practice. It is usually solved, if there are no complexities including gastrointestinal absorption disorder, by taking medicines on an empty stomach and avoiding foods interfering with LT4. Herein we present a rare case of a patient exhibiting malabsorption of LT4 with decreased membranous expression of ileal transporters. Case: The 22-Year-old female presented with sustained hypothyroid status despite medication of 7.8 µg/kg LT4. Medical history and LT4 absorption test (the absorption rate 8.4%) excluded pseudomalabsorption. No organic gastrointestinal disorder was found in the patient by blood chemistry, endoscopies, and abdominal computed tomography scan. The immunohistochemical analysis showed decreased membranous expression of LAT1 and LAT2 in distal ileum and ascending colon in the patient compared to 20 controls who have no thyroid disease. The expression of MCT8 in colon appeared at both nucleus and brush border in the patient, while it was limited to brush border in controls. The expression of other transporters was similar between the patient and controls. Conclusion: The changes of the expression of LAT1 and LAT2 in this patient showing LT4 malabsorption might help to understand the role of intestinal transporters in the absorption of LT4 in humans. The functional relevance of the decrement of LAT1 and LAT2 in this patient remains to be elucidated.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Hipotireoidismo/tratamento farmacológico , Transportador 1 de Aminoácidos Neutros Grandes/metabolismo , Síndromes de Malabsorção/diagnóstico , Tiroxina/farmacocinética , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Hipotireoidismo/metabolismo , Hipotireoidismo/patologia , Transportador 1 de Aminoácidos Neutros Grandes/genética , Síndromes de Malabsorção/genética , Síndromes de Malabsorção/metabolismo , Prognóstico , Tiroxina/uso terapêutico , Distribuição Tecidual , Adulto JovemRESUMO
OBJECTIVE: Peripheral blood mononuclear cells (PBMC) in culture release a biologically active human chorionic gonadotropin (hCG). This effect is detectable during pregnancy with a maximum between the 16th and 19th week. HCG plays an important role for the corpus luteum rescue during the early gestational age and possibly for the immunotolerance. This study was performed to investigate the relationships between the productivity of cultured PBMC of pregnant women and the ability to maintain early pregnancy, and whether 12-o-tetradecanoyl-phorbol-13-acetate (TPA) increases hCG sectetion by cultured PBMCs. MATERIALS AND METHODS: PBMC were obtained from 20 pregnant women between 16th to 19th week of gestation , and cultured with TPA. Culture cells were harvested and hCG mRNA were extracted and RT-PCR were performed. Culture supernatants were collected and hCG concentration were determined by commercial RIA methods. RESULTS: The mean age was 31.0 years old, 19 of 20 (95%) pregnant women's PBMC secereted hCG and expressed hCG mRNA, but in control group exept male hepatitis B patient, none of them produced hCG. TPA activated expression of hCG in PBMC in linear manner. CONCLUSION: Pregnant women's cultured PBMC secreted hCG, but not in non-pregnant or male. We could confirm the mRNA of hCG in PBMC as well in the placental control. The productivity of hCG in PBMC might be closely related with maintenance of early pregnancy.
