High Immune Responsiveness in a Family with Multiple Paraproteinaemia and Autoimmune Thyroid Disease

Abstract

Immune responsiveness was investigated in a family comprising 12 first-and seconddegree relatives, one of whom had K-myelomatosis, one IgA-A paraproteinaemia, two Graves' disease and a further two thyroid antibodies without disease. Relatives by marriage served as controls. Parameters of immune capacity studied were the humoral and cellular immune response to haemocyanin of Helix pomatia (HPH), dinitrochlorobenzene (DNCB) skin reactivity and in vitro lymphocyte proliferation capacity to phytohaemagglutinin (PHA). Mean antibody titres to HPH were higher in the family than in the control group in all main Ig classes and IgG subclasses after primary and secondary immunization, and the difference was statistically significant for IgG, IgG, and IgG, titres. This could not have been predicted from the (normal) serum Ig levels in this family. In vitro lymphocyte proliferation capacity to HPH after primary and secondary immunization was also significantly increased. DNCB skin reactivity also tended to be high in the family, whereas PHA-induced lymphocyte proliferation was normal. These findings support the idea that myelomatosis clusters in families with immune dysregulation.