CD40LG and plasma cell myeloma: There was 100% agreement on the need to have available guidelines for the management of immunodeficiency in hematological patients; to perform a baseline immunological evaluation in patients with chronic lymphocytic leukemia (CLL), multiple myeloma (MM), lymphoma and hematopoietic stem cell transplantation (HSCT) recipients; and to quantify serum IgG, IgA and IgM levels when SID is suspected.