Measurement of carbohydrate-deficient transferrin (CDT) in a general medical clinic: is this test useful in assessing alcohol consumption.

The aim of this study was to measure serum carbohydrate-deficient transferrin (CDT) in consecutive patients attending a general medical clinic with a range of alcohol intakes to determine its value in assessing such intake. Eighty-one consecutive patients (42 male, 39 female) aged 20-85 years (median = 49.5 years) attending an out-patient clinic were selected for the study. Each patient completed an alcohol diary detailing the units of alcohol consumed in the previous week, a CAGE questionnaire and an alcohol history, and underwent conventional blood tests including mean corpuscular volume (MCV), liver function tests, and gamma-glutamyl transferase (GGT). CDT was estimated using an enzyme immunoassay (CDTect, Pharmacia). The group comprised of 17 teetotallers, 28 light (<100 g/week), 23 moderate (100-400 g/week), and 13 heavy (>400 g/week) drinkers. Median serum CDT for heavy drinkers (25.5 U/l) was significantly higher than for the rest (median = 17 U/l, Kruskal-Wallis test, P = 0.01). Serum CDT correlated significantly with the CAGE score (Mann-Whitney test, P = 0.01), but poorly with alcohol diary records (r = 0.1, P = 0.4). However the correlations between GGT and diary records (r = 0.43, P = 0.001) and MCV with diary records (r = 0.5, P < 0.001) were significant. Sensitivity, specificity, and positive predictive value for elevated serum CDT were 69, 81 and 41% respectively in detecting heavy drinking. The positive predictive values for the various parameters were 43% for elevated serum GGT, 41% for raised erythrocyte MCV, and 75% for a positive score on the CAGE questionnaire. When a combination of the markers CDT, GGT, and MCV was used, elevation in two of the three markers detected heavy drinking with sensitivity of 85%, specificity of 88%, and positive predictive value of 61%. We conclude that, in out-patients with a wide range of alcohol intakes conventional markers such as serum GGT and erythrocyte MCV were more suitable than serum CDT for assessing alcohol intake. Serum CDT when used in combination with serum GGT and erythrocyte MCV was useful in detecting heavy drinking. The importance of careful history-taking including a standardized questionnaire is emphasized.

Diagnostic pitfall; interpretation of CA 19-9 concentrations in the presence of hepatic dysfunction.

A 50 year old man is described with hepatic dysfunction and chronic pancreatitis in whom greatly increased concentrations of the pancreatic tumour marker CA 19-9 combined with an abnormal appearance at endoscopic retrograde cholangiopancreatography lead to the false suspicion of pancreatic carcinoma. CA 19-9 concentrations should be interpreted with caution in patients with intrinsic liver disease or biliary obstruction.

Fine adjustment of thyroxine replacement dosage: comparison of the thyrotrophin releasing hormone test using a sensitive thyrotrophin assay with measurement of free thyroid hormones and clinical assessment.

Thyroxine replacement therapy for 21 adult patients with primary hypothyroidism was adjusted to the dosage at which each patient had a normal thyrotrophin (TSH) response to thyrotrophin releasing hormone (TRH). Clinical assessment and measurement of TSH (by sensitive immunoradiometric assay), free thyroxine (FT4) and free tri-iodothyronine (FT3) were made at this dosage and at higher and lower doses of thyroxine. Clinical observations, FT3 and FT4 assays were relatively insensitive to small alterations of thyroxine dosage, in contrast to which basal TSH measurements correlated well with TRH responsiveness and were sensitive to fine adjustments of thyroxine dosage.

Sheehan's syndrome presenting with type III hyperlipoproteinaemia.

A patient is described in whom the presenting feature of hypopituitarism was the development of palmar xanthomata associated with type III hyperlipoproteinaemia. Treatment of her secondary hypothyroidism with thyroxine caused resolution of the xanthomata and hyperlipidaemia, but the underlying compositional abnormality of the lipoproteins could still be observed.

Economy and efficiency in routine thyroid-function testing: use of a sensitive immunoradiometric assay for thyrotropin in a general hospital laboratory.

We measured thyrotropin (TSH) with a sensitive immunoradiometric assay (IRMA) in 2329 consecutive serum samples received for thyroid-function tests from hospital and general practice. Of these, 185 (7.9%) had TSH values less than 0.2 milli-int. unit/L: 33 (1.4%) were hyperthyroid, 20 (0.9%) were being treated for hyperthyroidism, 115 (4.9%) were receiving L-thyroxin, and 17 (0.7%) were clinically euthyroid but had severe non-thyroidal illnesses. In the first 506 serum samples, we also measured free thyroxin, free triiodothyronine (FT3), and total thyroxin. Thyroliberin (thyrotropin-releasing hormone, TRH) tests performed on 84 patients showed that an undetectable initial TSH (usually ascribable to therapy with thyroxin) predicted a flat TRH response. All untreated thyrotoxic patients had undetectable TSH. Experience confirmed that this TSH assay, in conjunction with a supplementary assay of FT3 when the TSH concentration is less than twice the limit of detection, is efficient and economical for routine evaluation of thyroid function in an unselected population.