visual message
at first glance, like most others, it took me a few to figure out what it was. then i was like "ok, i get it transparent cafe...coffee cup...maybe that's a coffee bean in the bkgrd..ok..i got it.."
however, later on i read your post that it is actually for a support forum for those who have had transplants, need a transplant or know ppl in either of those situations...NOW the story has changed.
logos are tricky; sometimes they warrant a very straightforward literal translation and then other times, they have the freedom of being kind of vague and interpretive.
problem is, right now, your subject matter - transplants, is a rather serious-based topic and having a "coffee / tea" themed logo could be seen as taking an important topic as non-serious.
i know with the name having "cafe" in it...automatically, one wants to think coffee, tea, starbucks, dunkin...anything relating to such, which could work for you. but i think you also need to take the transplant aspect into consideration and instead of the round object (bean?) in the background, maybe replace that with an image that could represent the "transplant" part of the name, which actually, is the most important of the two because that's the primary focus...those who have had, or need, transplants. Just a thought....