How to quantify the expression of CD45 isoforms from bulk RNA-seq data

Question

[eager_underdog]

I used Salmon to quantify transcripts from bulk RNA-seq data and generated gene-level quantifications with the summarizeToGene function from the taximeta package.

Now I'm interested in quantifying the expression of specific CD45 isoforms, such as CD45RA and CD45RO, from my data. Can anyone recommend a suitable tool or method for doing this?

Thanks in advance!