Nothing comprehensive that I've ever seen. There are a few in the Mid-East, IST supposedly has one and a few in Latin/South America.

I don't think so , I know of an Amex Lounge in MEX, and GRU and
I think there are some others.

While other SkyTeam carriers flying out of EZE provide SkyTeam Elite+ passengers (whether Elite+ from their program or any other SkyTeam airline) with lounge access when departing on a same-day international SkyTeam flight, CO refuses to provide the same lounge access benefits it provides to BusinessFirst customers at the very same airports. This kind of CO policy leads to some absurd situations at various airports across the world.

For example of absurd situations from this approach by CO, "listen to this." CO Platinums flying KL or AF or any other non-CO SkyTeam airline in coach out of ARN, CPH, OSL, etc., are provided lounge access to the very same facility that CO BF passengers are allowed to use; but if those CO Platinums fly CO in coach from the same airport they will be turned away. Some mornings at ARN -- especially in the summer -- I see this absurdity of a CO Plat flying CO in coach to EWR getting turned away while a CO BF passenger and a CO Plat flying KL or AF in coach gets in just fine -- this is all because CO instructs the lounges to specifically deny CO Plats flying in coach access from the same lounges that BF passengers use because CO does not want to pay for access.

I am on a COPA flight leaving at 5:15 am. Are there lounges open at that time for use? (I also have UA and AA club memberships).

I believe the Amex lounge is open for COPA flights , I though their flight was arount 2 AM ?

Did that lounge re-open yet? Last I was through EZE back in March it was still closed for renovations.

In june, I used Amex lounge, nothing else...

Yeah, it re opened a while ago, it is much bigger , and has 3 areas , the main lounge , the plat section and the Black Card Room

AmExp VIP and other Airport Lounge access
 

Here's the AmExp site page reporting AmExp Platinum info on Airline Lounge Access with major carriers and what appear to be only 3 AmExp operated VIP Lounges. The Priority Pass information is also referenced ... although, since I fly CO exclusively, I have not partaken.

http://www.americanexpress.com/lacid...plounges.shtml

I guess those are the only 3 :
MEX, EZE and GRU

That link is for Latin America and the Caribbean-issued cards. The IST lounge is only for Turkey-issued cards, though it is not AmEx operated, but it is not listed there. AmEx does a very bad job of posting a complete list anywhere, likely because the list varies depending on where one's card is issued.