Using Miller:
mlr --tsv --implicit-csv-header --headerless-csv-output \ put -S '$1=gsub($1,"[+].+$","")' then uniq -a inputfile and the output is:
ICR1 + ICR1 + ICR1 + IRT1 + IRT1 + IRT1 + LSR1 - LSR1 - LSR1 - NME1 + NME1 + NME1 + PWR1 - PWR1 - PWR1 - Q0017 - Q0017 - Q0020 - Q0020 - Q0020 -