My herbal therapeutics class recommends Devil's Claw (Harpagophytum procumbens) for pain and inflammation, Boswellia serrata for anti-inflammatory actions and modulating the immune system, nettle leaf (Urtica dioica folia) for inflammation and to help remove uric acid from the system. Licorice and rehmannia can be useful in an acute attack. There are others, of course, but these are just a few suggestions.
I haven't matched these with blood group B. It just happened that I had my folder in front of me when I read your post.