Abstract
Purpose :
To explore whether single cell analysis allows a more detailed characterization of the IGH clonality, gene usage and the correlation with MYD88 mutational status.
Methods :
Vitreous fluid or CSF (n = 12) from 9 cases with PVRL and 3 cases with chronic inflammation based on cytological examination and 12 months’ follow-up were recruited in accordance with the Singapore Personal Data Protection Act. Single B (CD19/20+, CD3-) cells were isolated using DEPArray™Nxt technology, followed by the single cell IGH sequencing and MYD88 mutation analysis.
Results :
Compared with bulk cell sequencing, single cellular characterization displayed more heterogeneous IGH profiles of targeted vitreous/CSF B cells. Higher frequency of the dominant IGH clone in PVRL patients was observed compared with chronic inflammation patients (p=0.0089, Figure 1A). Majority cases (66%) who were diagnosed as PVRL showed the IGHV3 and IGHV4 as dominant clone (Figure 1B). We screened each single B cells (n=61) isolated from PVRL cases for both IGH sequencing and MYD88 mutation. The presence of MYD88 L265P mutation was more frequently detected in the single B cells with IGHV5 (100%), IGHV4 (71%) and IGHV3-7 (68%) gene sequencing (Figure 1C).
Conclusions :
Single cells analysis of vitreous fluid or CSF displayed the complexity of tumor B cell population in PVRL, as well as the bias in the IGH gene sequencing and MYD88 mutational status in cellular level, which adds unique ontogenetic information for disease prognosis and development.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.