Rituximab may help aPL patients, says research

A pharmaceutical used to treat arthritis and cancer, called rituximab, might assist patients with antiphospholipid antibodies (aPLs) who experience aPL-related clinical problems that do not react to anticoagulation.

Appearing in the journal, Arthritis and Rheumatism, the study on rituximab was conducted by researchers from the Hospital for Special Surgery.

"This is the first study to systematically analyse rituximab in aPL-positive patients. Rituximab may have a role in treating a subgroup of aPL patients," said Dr Doruk Erkan, senior author of the study and an associate attending rheumatologist at Hospital for Special Surgery in New York City, US.

Researchers have known for a long time that inflammation and the formation of blood clots can be caused by aPLs, which increase the production of particular proteins.

Some aPL-positive people are healthy, however others have antiphospholipid syndrome (APS) and have arterial thrombosis, venous thrombosis or foetal loss.

People with non-criteria APS manifestations can have low cardiac valve disease, platelet counts (thrombocytopenia), memory problems (cognitive dysfunction), skin ulcers and kidney disease (aPL-nephropathy).

Rituximab can obliterate B-cells and is at present used in patients with leukemia and rheumatoid arthritis.

"The idea is if you kill the inflammatory B-cells, they can not secrete the antiphospholipid antibody that can cause problems," stated Dr Erkan.

In the past research has shown that B-cells, a type of white blood cell, exude aPLs and that abolishing B-cells can thwart the development of APS in mice.

The rheumatology experts concluded that the drug may be a likely treatment for some non-criteria APS manifestations.

This is great news because while anticoagulation treatments can help with some of the complications experienced by APS patients, they are not viable when treating the non-criteria APS manifestations.

Low platelet counts and the destruction of red blood cells causing anemia, cardiac heart valve disease, memory problems and kidney disease do not typically react to anticoagulation therapy, explained Dr Erkan.

"Our future goal is confirming our results with a randomised controlled trial and we also need to try to identify which patients will respond to rituximab. We need to find the predictors of response," concluded the expert.

Posted by Fiona Griffiths