Makro-TSH - ett ovanligt in vitro-fenomen som kan ge felaktig diagnos. Samarbete mellan kliniker och laborativ verksamhet viktigt
Sammanfattning
During investigation of thyroid function it is not unusual to find an abnormal value for serum TSH with normal values for peripheral
thyroid hormones. However this does not always reflect a functional thyroid disturbance. Analytical interference of TSH measurement is an
example when antibodies in the patient’s serum interfere with the measurement of TSH giving a false high serum TSH value. Another
unusual case is macro-TSH that represents a macromolecular complex between TSH and immunoglobulin that decreases its renal
clearance giving a spuriously elevated serum TSH value. By discussing a patient with macro-TSH we would like to remind the clinicians
about the importance to have a direct communication with the clinical chemistry department especially when a patient without any clinical
signs for thyroid disease has an elevated isolated TSH.