Induction prior to bone marrow transplantation in hematological malignancies often includes total radiotherapy and chemotherapy. This treatment leads to death of blood cells and release of multiple factors (interleukin, interferon, cytokine, etc.) modulating the immune response. Some drugs used in a chemotherapy can clearly induce capillary leak (gemcitabine). If a leak occurs after an induction radio-chemotherapy, the risk of serious complications is enormous because the regulatory mechanisms are disrupted (loss of platelets, of white blood cells and interference of many immunological factors whose action are not always clear).
Bevacizumab is a monoclonal antibody (IgG1) that binds VEGF (Vascular Endothelial Growth Factor) and prevents the proliferation of small vessels (capillaries). This drug is used in cancers of the bowel, breast, lung and kidney. New studies are made on lymphomas and other tumors, often in combination with other chemotherapy drugs
The role of MGUS in the SCLS is not clear. It results from the production of an abnormal immunoglobulin by a clone of plasma cells. This protein does not induce a capillary leak. But it reflects a more complex immunological disorder not yet clearly understood. The idea to remove the paraprotein (MGUS) is good in itself. Indeed if we can get rid of the clone of plasma cells, one can hope to eliminate the immunological disorder. In my case, I tried chemotherapy with high-dose Thalidomid and I had two attacks of SCLS during treatment; one of these was a very serious leak. Then I tried the combination Thalidomid & corticosteroids as the classical chemotherapy against multiple myeloma. Unfortunately MGUS did not disappear and I had to stop the treatment because of severe side effects of Thalidomid (polyneuropathy) and corticosteroids (neuro-psychological disorders, diabetes, infections).
Finally, the best _current_ treatment of SCLS is the monthly injection of polyclonal immunoglobulins (IVIG).