c++ excel blank cells

// Get Data
string itemPartNumber;
int itemQuantity;
int iLoop = 2; // Skip the column title
bool exitLoop = false;

ClearList(ref bomList);  //Clear my destination list

while (!exitLoop)
{
    var itemPn = xlsSheet.Cells[iLoop,1].Value2;
    var itemQu = xlsSheet.Cells[iLoop,2].Value2;

    exitLoop = (itemPn == null);
    if (!exitLoop)
    {
        itemPartNumber = (string) itemPn;
        itemQuantity = Int32.Parse(itemQu.ToString());
        ComponentPNQ itemList = new ComponentPNQ(itemPartNumber, itemQuantity);
        bomList.Add(itemList);
        iLoop++;
    }
}