elevated ferritin in and of itself is an acute phase reactant and can be elevated in a number of thing. It is a combination of multiple lab and x-ray findings with the clinical presentation that makes the diagnosis. Again it is fairly unique in its presentation of you know what you are looking for. Other mimics usually declare themselves pretty quickly
Sure and a huge spike in Covid Presumptive cases with large ferritin levels could include a few patient’s that have other causes for their ferritin spikes. Yet for those very sick with covid we see that pattern repeatedly.