[Immune reactivity in patients with disorders of lipid metabolism]

The accidental observation of a selective IgM-deficit in a family with hyperlipoproteinaemia type II caused the working hypothese of close interactions of lipometabolism and immunoreactivity. In 69 patients with hyperlipoproteinaemia the quantitative determination of the immunoglobulins G, A and M was performed by the Mancini-test. All decreased values were repeated in a second determination at another moment. In 9 patients with hyperlipoproteinaemia and deficit of immunoglobulins we determined the T-lymphocytes by means of the sheep erythrocyte rosette test, the B-lymphocytes with the help of the method of direct immunofluorescence and the mouse erythrocyte rosette test. Altogether 14 of the 69 patients with hyperlipoproteinaemia showed reproducible deficit of immunoglobulins, which is statistically significant. The immune defect appeared above all as decrease of IgA (11 patients) isolated 8 patients or in combination with IgM-deficit (2 patients) and IgG-deficit (1 patient). 2 resp. 1 patient showed selective IgG- or IgM-deficit. Clinical symptoms of an immune defect were not recognizable anamnestically and prospectively. In the 9 patients who were immunologically further characterized the T-lymphocytes were in the region of the norm or were increased, the subpopulation of B-lymphocytes which reacted with mouse erythrocytes was normal or increased. The classification to the types of hyperlipoproteinaemia of the altogether 14 deficient patients showed the order IIa, IV, IIb. The original working hypothesis could be supported by the present findings, though an obvious clinical importance is not yet to be recognized. Changes of the membrane lipids of lymphocytes, interventions through the prostaglandin system and effect via suppressor cells must be discussed causally.