Immunohistological changes in dilated cardiomyopathy induced by immunoadsorption therapy and subsequent immunoglobulin substitution

Background-Immunoadsorption (IA) and subsequent immunoglobulin (Ig) G subst itution represent an additional therapeutic approach in dilated cardiomyopa thy (T)CM). It remains to be elucidated whether this treatment modulates my ocardial inflammation, which is possibly a causal factor of ventricular dys function. Methods and Results-From 25 DCM patients (EF < 30%), 12 patients were rando mized for IA therapy and subsequent IgG substitution at 1-month intervals u ntil month 3. Before (<7 days) and after IA therapy, right ventricular biop sies were obtained from all patients. Biopsies were also obtained at interv als of 3 months from 13 patients without IA/IgG treatment (controls). IA/Ig G treatment induced improvement in left ventricular ejection fraction from 21.3 +/- 1.7% (+/- SEM) to 27.0 +/-1.3% (P <0.01 versus baseline/controls) and reduction of the beta -receptor autoantibody serum levels (P <0.01 vers us baseline/controls). The number of CD3 cells decreased from 5.7 +/-0.8 to 2.9 +/-0.5 cells/mm(2) (P <0.01 versus baseline/controls). This decline wa s paralleled by a decrease in CD4 (P <0.01 versus baseline/controls) and CD 8 (P <0.05 versus baseline/controls) lymphocytes. The number of leukocyte c ommon antigen-positive cells (leukocytes) was reduced from 20.0 +/-3.2 to 9 .9 +/-2.8 cells/mm2 (P <0.01 versus baseline/P <0.05 versus controls). HLA class II expression decreased from 2.1 +/-0.7% to 1.1 +/-0.4% (P <0.05 vers us controls/baseline). The number of immunopositive cells and the expressio n of HLA class II in controls remained stable. In both groups, the degree o f fibrosis remained unchanged. Conchsions-IA and subsequent IgG substitution mitigate myocardial inflammat ion in DCM.