PCV = positive crankcase ventilation. Air is recirculated from the valve cover to the intake hose to prevent buildup of hydrocarbon residue (which causes sludge) inside the engine.

It's not the type of filter that dictates whether you need to place a breather on the PCV valve. It's the tube. If you replace your stock intake tube with an aftermarket one that has no bung for the PCV hose, then you need a breather. You can't just seal up the PCV connection on the valve cover (or wherever it is, on your engine) as this is bad for your engine.

Of course, it's also bad to have a breather, as this vents unburned hydrocarbons into the atmosphere... causing more pollution. Thus, most modern intake pipes have bungs for these hoses.