The odd couple = the weird husband and wife?

I believe that this has already been explained to you. The Odd Couple was a vey successful play on Broadway by Neil Simon, from which an equally successful motion picture was made. The central characters of the play were bachelors who shared an apartment. One was loud, obnoxious, lazy except in his job (he was a sports writer) and a slob. The other was a prim, fastidious man who was obsessed with cleanliness and keeping the apartment neat and fashionable. The two characters were opposites, and so they were "the odd couple."

This expression has now entered the language to mean any unlikely pair which are nevertheless associated with one another. I'm not going to read your link for more context--the context is obvious to anyone familiar with the cultural antecedants of the locution "the odd couple."

The "odd couple" in this case are "autoimmunity" and "immunodeficiency".

two unlike people, places or things that interact with each other = odd couple.

Thanks.
It's a title, so I'd better be more careful.

Thank you all.