Naslov
Unusual phenotypes unveiled during the routine polychromatic immunophenotyping of PID patients: getting out of the box is beneficial

Autori
Bulat Lokas, Sandra ; Zenić, Lucija ; Živković, Jelena ; Nogalo, Boro ; Turkalj, Mirjana ; Polančec, Denis.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, ostalo, stručni

Skup
33rd Congress of the International Society for Advancement of Cytometry

Mjesto i datum
Prag, Češka Republika, 28.04.2018. - 02.05.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Flow cytometry, PID, IgA

Sažetak
Introduction: Flow cytometry-based immunophenotyping is the method of choice in investigating changes in immune cell populations in different immunological diseases. Primary immunodeficiencies (PID) are a group of more than 300 chronic disorders caused by genetic defects affecting development and/or function of immune system. Consequently, PID patients are more susceptible to recurrent infections, autoimmune disorders and malignancy. The most common group of PID are antibody deficiencies. Methods: Flow cytometry immunophenotyping of peripheral blood was performed using two 6-colour antibody panels consisted of CD3, CD4, CD8, CD16, CD19, CD27, CD45, CD56 and HLA-DR surface markers in order to analyze T cells, B cells and NK cells. Samples were prepared using lyse+fix /wash protocol. The samples were acquired using the Navios™ flow cytometer (Beckman Coulter, USA). Data was analyzed using the FlowLogic™ software (Inivai Technologies, Australia) Results: Extended analysis was performed on 500 pediatric patients using polychromatic immunophenotyping revealing three interesting immunophenotypes: the CD3dim population (one patient), CD3-CD16lowCD56+ NK cells (more than 10 patients) and the CD3-CD16+CD56+CD19low lymphocytes (more than 10 patients). In some patients the unusual phenotypes were seen in the follow-up analysis, showing an increasing trend. The CD3dim population was detected in a 13 year-old patient diagnosed with selective IgA deficiency and a suspicion of common variable immunodeficency. During three consecutive immunophenotyping within one year, the presence of the CD3dim cells, additionaly characterised as CD8+, CD16+ and CD56dim increased from 3.5% to 6.5% of total lymphocytes. The second phenotype we noticed was CD3-CD16lowCD56+ NK cells, otherwise reported in HIV seropositive patients with NK cell deficiency (Hu et al, J Acquir Immune Defic Syndr Hum Retrovirol, 1995). The clinical relevance of this NK cell subset in pediatric primary immunodeficiency patient is yet to be determined. Finally, in at least 12 patients we detected a peculiar population of NK cells with the CD3-CD16+CD56+CD19lowphenotype. Detailed analysis of medical history of all of these patients is ongoing in order to find correlatation between the phenomenon of the observed phenotypes and clinical outcome. Conclusion: In diagnosis of PID, comprehensive immunophenotyping of whole blood using polychromatic flow cytometry panels is a widely used method. However, a detailed analysis of FCS data should be performed and carefull investigation of patient immunophenotypes implemented to daily routine: plotting markers otherwise reflecting aberrant antigen expression might reveal unusual phenotypes.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

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