Does platelet activity play a role in the pathogenesis of idiopathic ischemic priapism?

ABSTRACT Purpose Mean platelet volume (MPV) is used to measure platelet size and is defined as a potential marker of platelet reactivity. Higher MPV levels have been defined as a risk factor for increased incidence of intravascular thrombosis and its associated diseases. We aimed to determine whether a relationship exists between the MPV and veno-occlusive component of idiopathic ischemic priapism (IIP). Materials and methods Between 2010 and 2014, 38 subjects were analyzed in two groups. One was composed of 15 patients with diagnosis as IIP in our institute, and the other contained 23 healthy control subjects. Complete blood count reports were retrospectively evaluated in both groups. MPV, platelet count (PLT), platelet distribution width (PDW), white blood cells (WBC), red blood cells (RBC), hemoglobin (Hb), reticulocyte distribution width (RDW) were measured in both groups. : Results The mean ages were similar in IIP patients (45.86±15.82) and control subjects (47.65±10.99). The mean MPV values of IIP patients were significantly higher than control subjects (p<0.05). In contrast, also PLT counts were significantly lower in IIP patients, compared to control subjects (p<0.05). The mean hemoglobin and WBC values were significantly lower in control group (p<0.05). There was no significant difference of RBC, PDW and RDW values in both groups. Conclusions We found that the MPV was significantly higher in IIP patients compared to control subjects. The high MPV levels may have contributed to the veno-occlusive etiopathogenesis of IIP disease. We strongly suggest further prospective studies to recommend the use of MPV in routine practice.

Hematological parameters in sick cell anemia patients with and without priapism

Priapism was associated with certain hematological parameters in sickle cell anemia [SCA] patients in one report but not in another. We studied differences in haematological parameters between SCA patients with and without priapism. Eighteen patients with SCA who presented with acute priapism during the years 2001-2004 were compared with age- and sex-matched SCA patients without priapism with respect to hematocrit, reticulocyte count, level of irreversibly sickled cells [ISC], percentage of haemoglobin F [Hb F], total leukocyte and platelet counts. SCA patients with priapism had a mean hematocrit of 0.28 L/L which was significantly higher than the mean hematocrit value of 0.24 L/L [P<0.05] in patients without priapism. The mean reticulocyte count of 8% in patients with priapism was significantly lower than mean reticulocyte count of 12% [P<0.05] in patients without priapism. The level of ISC of 3% in patients with priapism was significantly lower than the level of 6.5% [P<0.05] in patients without priapism. There was no statistically significant difference in the mean levels of Hb F [7% vs. 6%]. Patients with priapism had a mean leukocyte count and mean platelet count that did not significantly differ from values in patients without priapism. SCA patients with priapism had a lower rate of hemolysis, resulting in a higher hematocrit and greater blood viscosity, which increased the risk of corpora cavernosal sickling and blockade. Hence, a relatively high hematocrit is a risk factor for the development priapism in patients with sickle cell anemia