I'm also using the E-5186 and my RSRQ can go to -3dB which might be an indication of LTE-A but I was getting that even before the coverage map indicated I should have LTE-A.
That's the thing, I'm not 100% sure. My RSRQ is -3dB, the map says I'm in an LTE-A area and my fastest speedtest was 100Mb/s so I have a strong gut-feeling I'm getting LTE-A but would love something that tells me if that is indeed the case...