“It is one of the leading LPO’s” or it should be “LPO”.
It is one of the leading LPOs.
You may see some people using an apostrophe in cases like this, but there is no reason for it.
Only use an apostrophe to create a plural if inserting a s causes confusion. For example: “How many a’s and i’s are in the following paragraph?” or “Microsoft Word thinks you must include a comma before all “which’s” in its grammar check.”