Reticulated platelets and thrombopoietin in schistosomiasis patients

Abstract

Schistosomiasis mansoni is a non-cirrhotic liver disease. In cirrhosis patients with portal hypertension, a decreased number of reticulated platelets associated with increased thrombopoietin serum levels were reported. We previously reported a 120/nl platelet cutoff level as a marker of clinically significant portal hypertension in schistosomiasis patients. To evaluate reticulated platelet counts and thrombopoietin serum levels (TPO) in schistosomiasis patients and correlate them with portal hypertension markers. Thirty-three schistosomiasis patients without co-morbidities were endoscopically classified as those with (n = 19) or without (n = 14) clinically significant portal hypertension. Flow cytometric determination of reticulated platelets was performed using CD41 antibody and thiazol orange. Ultrasonographic examinations were performed according to the Niamey protocol. TPO and hyaluronic acid serum levels were determined in duplicate using ELISA methods. The platelet number of 120/nl discriminates the two groups with 100% accuracy and 100% positive and negative predictive values, and correlates with spleen length and portal and splenic vein diameters. Differences in reticulated platelets and hyaluronic acid serum levels between both groups were significant (P = 0.025 and 0.012, respectively), but thrombopoietin serum levels were not (P = 0.769). Schistosomiasis patients with portal hypertension have increased reticulated platelets associated with normal TPO serum levels.

Hemostatic Dysfunction Is Increased in Patients with Hepatosplenic Schistosomiasis Mansoni and Advanced Periportal Fibrosis

“…Levels of protein C and antithrombin were significantly lower in our patients compared to the healthy controls, presumably reflecting hepatic dysfunction caused by portal hypertension and advanced periportal fibrosis [10], [20]–[22]. Although bleeding events in hepatosplenic schistosomiasis are associated with portal hypertension [20], the deficient production of coagulation factors does not seem to aggravate the situation due to a balance between the reductions in pro- and anti-coagulation proteins.…”

“…Köpke-Aguiar et al [20] also reported that levels of thrombopoetin and reticulated platelets are normal in schistosomiasis patients with portal hypertension and that the bone marrow produces normal amounts of platelets. Thrombocytopenia in schistosomiasis patients may occur because of splenic retention due to poor portal blood drainage, or because platelets are trapped in the sinusoidal spaces of the fibrotic liver [20]. Our study confirms that thrombocytopenia is common in patients with hepatosplenic schistosomiasis, and that this tends to be higher in the advanced stages of periportal fibrosis.…”

“…The thrombocytopenia in hepatosplenic schistosomiasis is compensated, at least in part, by increased levels of von Willebrand factor that enable platelets to adhere and aggregate at sites of vascular injury [5], [18], [19]. Köpke-Aguiar et al [20] also reported that levels of thrombopoetin and reticulated platelets are normal in schistosomiasis patients with portal hypertension and that the bone marrow produces normal amounts of platelets. Thrombocytopenia in schistosomiasis patients may occur because of splenic retention due to poor portal blood drainage, or because platelets are trapped in the sinusoidal spaces of the fibrotic liver [20].…”

Correlation Between Platelet Count and Both Liver Fibrosis and Spleen Diameter in Patients With Schistosomiasis Mansoni

“…The strong correlation between the number of platelets and the spleen diameter observed in SM could also be strengthened by the absence of other factors that induces thrombocytopenia, which are found in the cirrhosis (25) . For example, in this parasitic disease the production of thrombopoietin is higher that described in the cirrhotic patients, as well as in the SM antibodies antiplatelets are not observed as found in the HCV chronic liver disease (11,25) . Recently, a smaller number of platelets and larger spleen diameter have been described in patients with SM and with esophageal varices in comparison to those without varices (1) .…”

“…Indeed, Koepke-Aguiar et al (11) found more severe thrombocytopenia in patients with advanced forms of hepatosplenic schistosomiasis with portal hypertension. In addition, studying 47 patients with SM and 13 controls, Lambertucci et al (12) found a mean number of 194 x 10 9 /L platelets in the controls and 44 x 10 9 /L in patients with severe periportal fibrosis, as assessed by ultrasound.…”