我沒有查到相關文本 - 回複：Jiang老師, 7月2日遞的485 PENDING,also filed 131, 這兩天可以回

You don't have to wait for I-485 receipt, as long as you were physically in US when filing I-485, however your AP (I-131) may be deemed void if you leave the country before its issuance, although at least one whose experience beat me.

http://web.wenxuecity.com/BBSView.php?SubID=immigration&MsgID=316214