Lymphocyte and erythrocyte turnover in thoracic duct lymph in patients with schistosomal hepatosplenomegaly and portal hypertension.

In 60 patients with hepatosplenic schistosomiasis and portal hypertension and in 20 control subjects, the turnover of erythrocytes and lymphocytes circulating in thoracic duct lymph was compared. Despite slight anemia in most patients with schistosomiasis, there was a greatly accelerated extravascular splanchnic circulation rate of erythrocytes. Lymphocytes also circulated more rapidly, but in contrast to erythrocytes, the peripheral blood lymphocyte count was elevated in schistosomal patients. Although thoracic duct lymph flow was increased at all stages of schistosomiasis, it was less rapid in "ascitic" and "varix bleeders" and thus the extravascular circulation turnover of erythrocytes and lymphocytes appeared to decline with chronicity of disease. The more rapid lymphocyte and erythrocyte "turnover," however, was almost entirely due to increased formation of interstitial fluid (greater lymph flow) suggesting that a prime regulator of splanchnic cellular migration was "solvent drag." These findings may derive from deranged portal microvascular dynamics (e.g., increased microvascular pressure, collagen deposition in Disse's space, capillarization of hepatic sinusoids, presinusoidal obstruction) as well as generalized host immunoresponsiveness to schistosomal infection.