A business meeting of the working group was held in June 2023 where the following topics were discussed:

• The rules for workshop organization were refreshed
• The provision of workshop materials (serum and DNA samples) was discussed again
• Organization of the next GIWP workshop
• ISBT-oriented publications (HNA-3 as erythrocyte antigen)
• Education officer

As the Steering Committee has already decided to organize an international granulocyte immunology workshop every two years, the next workshop will take place in 2024. The 2024 workshop will be organized by Dr. Daisuke Takahashi from Japan.

The meeting reiterated that all new applicants to the IGIW workshop must submit at least 50 mL of a characterized serum in addition to the required documentation.

A rule for the publication of new antigens was then discussed. For each new antigen related to HNA that has not yet been reported, the presence of a new antigen must be confirmed by three different reference laboratories.

It was requested (as a multicentre activity) to evaluate the presence of CTL-2 on erythrocytes. A further working group meeting was to be held after completion of the test to discuss the results. However, no results are yet available.