Getting multiple contact by email to then retrieve value of custom field

I am using the PHP iSDK, I have created an affiliate portal on a wordpress site, essentially the way it works is when an affiliate submits a lead it store this information in the wp database as well as infusionsoft. In the portal affiliates can view the leads they submitted, these values are pulled from the wp database. However what I would like to do is set it up for my client so that he can put a value in the “Loan Status” custom field i have created and then have this value displayed in the appropriate loan in the table in the portal.
using
path = _SERVER[‘DOCUMENT_ROOT’];
$path .= “/scripts/isdk.php”;
require_once ($path);
$app = new iSDK();
if ($app->cfgCon("*****")) {
$returnFields = array(’_LoanStatus’);
$conDat = $app->dsLoad(“Contact”, 43434, $returnFields);
}

I am able to retrieve the value from that custom field, but that is obviously just for that contact by its Id, I have tried to get contact by email but doing so does not return the value of the custom field. Is there a way I can pull the email from the wordpress database, pass that variable into the script and then search for those contacts via email to then get each of their custom field (_LoanStatus) so i can then echo it in the table?

Sorry for the delay in getting to your question. Can you show us what code you are using for the finding the contact by email? You should be able to still get the custom field when getting a contact by email.