Plasma DNA as cell death marker in elderly patients.

Plasma DNA increases where cell death occurs in vivo. To investigate its significance in elderly patients, plasma DNA was assayed in 79 institutionalized patients over 68 years of age. The patients were divided into two groups: group I comprises 39 patients suffering from various acute or chronic illnesses; group II comprises 40 patients without chronic disease, and free of any clinical or biological symptoms of any infectious or inflammatory process. Plasma DNA was higher in group I than in group II (p < 0.0001) and in group II than in a control group of middle-aged subjects (p < 0.05). In group I, increase in plasma DNA concentration was found in various pathological situations associated with cell death phenomena, including infections, cancers with metastasis, hepatitis, irreversible cardiac failure, severe respiratory insufficiency and thrombophlebitis. Plasma DNA concentrations were not correlated with erythrocyte sedimentation rate, fibrinogen concentration, hemoglobin concentration or leukocyte count. In group I, as well as in the overall population, survival after 1 month was significantly reduced in patients with increased concentrations of plasma DNA. In conclusion, plasma DNA as a marker of cell death phenomena occurring in vivo, could be helpful for follow-up and management of elderly patients.