Naslov
Dealing with interferences caused by presented M- protein

Autori
Dojder, Ana ; Vuljanić, Dora ; Kuktić, Ivona ; Radišić Biljak, Vanja ; Šegulja, Dragana ; Nikolac Gabaj, Nora ; Šimundić, Ana-Maria

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Clinical Chemistry and Laboratory Medicine / Plebani, Mario - Berlin : Walter de Gruyter, 2019, EA8-eA8

Skup
5th EFLM Conference on Preanalytical Phase

Mjesto i datum
Zagreb, Hrvatska, 22.03.2019. - 23.03.2019

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
preanalytical phase, bilirubin, interference, multiple myeloma, M-protein

Sažetak
Background M-proteins are endogenous interferents. Although M-protein interference has long been recognized, detection and management of samples affected by M-protein interference remains a challenge for laboratories worldwide. Here we present a case of M-protein interference on direct bilirubin measurement and how to deal with it in order to report accurate and reliable results to the requesting physician. Material and methods A 76 year old female patient with a previously known diagnosis of multiple myeloma has had her regular check-up. Her serum proteins were 95 g/L at the time. Concentrations of direct and total bilirubin analyzed by AU860 (Beckman Coulter, USA) analyzer were -12.3 and 8.5 µmol/L, respectively. Since M-protein interference was suspected, sample was diluted with distilled water (1:10 ratio) to gain the lower concentration of M-proteins, treated with PEG to precipitate them, and treated with HBT to exclude the heterophilic interference. Once interference was confirmed, sample was sent to two other laboratories and analyzed on two different analyzers: Cobas 6000 (Roche, Switzerland) and Architect c8000 (Abbott, USA). Results The direct bilirubin concentration in diluted sample was 3.0 µmol/L. It was 4.0 µmol/L after PEG precipitation and -2.0 µmol/L after HBT treatment. Direct bilirubin concentration on different platforms were as follows: 1.6 µmol/L on Cobas 6000 and 2.8 µmol/L on Architect, revealing no interference. Conclusion In case when the interference of M- proteins is suspected, PEG precipitation and sample dilution with distilled water is sufficient to confirm interference. If accurate result is necessary, sample should be analyzed on a different instrument where interference is not present. HBT treatment is not effective in eliminating M-protein interference. Communication with a patient and a requesting physician is vital for proper management of this type of interference.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

POVEZANOST RADA