[Serum neopterin in dilated cardiomyopathy]

RIA was used to measure the level of neopterine and beta 2-microglobulin in the sera of 43 patients with a verified diagnosis of dilated cardiomyopathy (DCMP). In DCMP patients, the mean level of neopterine was 11.25 +/- 1.05 nM/l and was significantly higher than in donors (5.6 +/- 0.5 nM/l). The concentration of neopterine exceeding 9 nM/l was discovered in 55% of DCMP patients. The rise of neopterine concentration was particularly marked in patients with inflammatory reaction in the myocardium according to endomyocardial biopsy. In that patients' group, the mean level of neopterine was 12.9 +/- 2.02 nM/l while the rise of its concentration over 9 nM/l was recorded in 9 (81%) of 11 patients examined. The correlation was established between the rise of the concentration of neopterine and beta 2-microglobulin. In patients with the concentration of neopterine over 9 nM/l, the mean level of beta 2-microglobulin constituted 3.33 +/- 0.32 mg/l and in patients with the normal concentration of neopterine, it amounted to 1.91 +/- 0.18 mg/l. The growth of the concentration of beta 2-microglobulin in the groups of patients under comparison was seen in 79 and 14% of cases, respectively. It is concluded that neopterine measurements are advisable in the laboratory diagnosis of myocarditis in DCMP patients. Potential mechanisms of the rise of neopterine formation are discussed from the standpoint of hyperinterferonemia.