PREFIX : <http://example.org/ns#>
PREFIX fn: <http://www.w3.org/2005/xpath-functions#>

SELECT ?x
WHERE {
##  ?item :q ?q  OPTIONAL {    { ?item :p ?p .FILTER(?p!=?q) } }

    ?item1 :q ?q
        FILTER(?p!=?q)
      ?item2 :q ?q .
}