Use of anti-idiotypic antibodies to demonstrate rheumatoid factor producing bone marrow cells in essential mixed cryoglobulinaemia.

Specific cells producing rheumatoid factor (RF) were demonstrated in a bone marrow preparation of a patient with essential mixed cryoglobulinaemia. This was achieved by the use of labelled anti-idiotypic antibodies raised against purified RF from the patient's circulating cryoglobulin. This technique may be applicable to other diseases in which specific antibodies are pathogenetically implicated. The more precise demonstration of specific antibody-producing marrow cells may in addition have therapeutic implications.