CONTEXT AND OBJECTIVES Sickle cell disease (SCD) is the most common genetic disorder among people of African descent, affecting approximately 3,500 newborns each year in Brazil. Hydroxyurea (HU) is the only effective drug to treating patients with SCD, thereby reducing morbidity and mortality. The objective was to analyze the effects of HU on SCD patients at our institution. DESIGN AND SETTING Retrospective study conducted at a sickle cell centre in Ribeirão Preto, São Paulo, Brazil. METHODS We analyzed clinical and laboratory data on 37 patients. The hematological parameters and clinical events that occurred during the year before and the first year of treatment with HU were analyzed. The mean dose of HU was 24.5 ± 5.5 mg/kg/day. RESULTS There were rises in three parameters: hemoglobin (8.3 g/dl to 9.0 g/dl, P = 0.0003), fetal hemoglobin (HbF) (2.6% to 19.8%, P < 0.0001) and mean cell volume MCV (89 to 105 fl, P = 0.001); and reductions in the numbers of leukocytes (10,050/µl to 5,700/µl, P < 0.0001), neutrophils (6,200/µl to 3,400/µl, P = 0.001), platelets (459,000/µl to 373,000/µl, P = 0.0002), painful crises (1.86 to 0.81, P = 0.0014), acute chest syndromes (0.35 to 0.08, P = 0.0045), infections (1.03 to 0.5, P = 0.047), hospitalizations (1.63 to 0.53, P = 0.0013) and transfusions (1.23 to 0.1, P = 0.0051). CONCLUSION The patients presented clinical and hematological improvements, with an increase in HbF and a reduction in the infection rate, which had not been addressed in most previous studies.

Microparticles (MPs) are present in healthy subjects and their concentration increases in patients at high risk of thrombosis. We evaluated 10 patients with sickle cell anemia (SCA) treated with hydroxyurea (HU) and 13 SCA patients without this treatment. MP concentrations were determined by flow cytometry. Coagulation was evaluated using the thrombin-antithrombin complex (TAT) and D-dimers. Total MP concentrations were increased in the HU-treated group (265 × 106/ml vs. 67.45 × 106/ml; p = 0.0026), as well as MPs derived from RBC (67.83 × 106/ml vs. 26.31 × 106/ml; p = 0.05), monocytes (51.31 × 106/ml vs. 9.03 × 106/ml; p = 0.0084), monocytes with tissue factor (TF) expression (2.27 × 106/ml vs. 0.27 × 106/ml; p = 0.0058), endothelium (49.42 × 106/ml vs. 7.23 × 106/ml; p = 0.007) and endothelium with TF (1.42 × 106/ml vs. 0.26 × 106/ml; p = 0.0043). Furthermore, the concentrations of TAT (7.56 vs. 10.98 µg/l; p = 0.014) and D-dimers (0.65 vs. 1.29 µg/ml; p = 0.007) were reduced with HU. The MP elevation may suggest a direct cytotoxic effect of HU. Another explanation is a cell surface increase secondary to a megaloblastic process, resulting in increased vesicle release. In our opinion, the known benefits of HU on SCA patients, along with the reduction in coagulation activation, surpass its potential detrimental effect on MPs. Future studies should elucidate the role of MPs and demonstrate their significance in different contexts. © 2014 S. Karger AG, Basel

CONTEXT: Rhabdomyolysis is a severe and life-threatening condition in which skeletal muscle is damaged. Acute renal failure due to rhabdomyolysis has been widely described and its main pathophysiological mechanisms are renal vasoconstriction, intraluminal cast formation and direct myoglobin toxicity. OBJECTIVE: To report on a case of acute renal failure (ARF) induced by rhabdomyolysis due to strenuous exercise and alcohol abuse and to describe the pathophysiology of this type of ARF. CASE REPORT: A 39-year-old man arrived at the hospital emergency service with swollen legs and lower extremity compartment syndrome. He was oliguric and had serum creatinine and urea levels of 8.1 mg/dl and 195 mg/dl, respectively. The diagnosis of rhabdomyolysis was made through clinical and laboratory findings (creatine kinase activity of 26320 IU/l). The initial treatment consisted of fluid replacement and forced diuresis. The specific treatment for compartment syndrome, such as fasciotomy, was avoided in order to prevent infection. Partial recovery of renal function was recorded, after ten hemodialysis sessions. Complete recovery was observed after two months of follow-up.

The objective of this study was to verify the evolution of pregnancies in sickle cell patients followed at one institution over a period of 12 years (January 2000 to June 2012). The study evaluated 34 pregnant women with sickle cell disease with a mean age of 23.9 ± 5.3 years. The incidence of obstetric complications, non-obstetric complications linked to sickle cell disease and complications in the newborn were analyzed. A total of 26% of the cases reported previous miscarriages, 20% had preterm labor, 10% had pre-eclampsia, and 5% had gestational diabetes. Forty-one percent of the deliveries were cesarean sections and 29% of patients required blood transfusions. In respect to sickle cell disease, 62% of patients had vaso-occlusive crises, 29% had acute chest syndrome, 23% had urinary tract infection, 15% had impaired cardiac function and 6% developed pulmonary hypertension. Only one patient died in the postnatal period due to acute chest syndrome. The mean gestational age was 37.8 ± 2.63 weeks, and mean newborn weight was 2.809 ± 643.8 g. There were seven fetal losses, including three stillbirths and four miscarriages. The impact of transfusion therapy on the incidence of maternal–fetal complications during pregnancy was evaluated. Pregnancy in sickle cell patients is still associated with complications. Although no statistical difference was observed between transfused and non-transfused women, there were no deaths (fetal or maternal) in transfused patients whereas one maternal death and three stillbirths occurred in non-transfused women. A larger study of sickle cell pregnant women will be necessary to elucidate the actual role of transfusion during pregnancy in sickle cell disease.

Intrahepatic cholestasis (SCIC) is an uncommon but potentially fatal complication of sickle cell disease (SCD), with a high death rate, observed mainly in patients with homozygous sickle cell anemia. Herein, we describe a case of severe SCIC treated successfully with aggressive manual exchange transfusion (ET). The patient was admitted with enlarged liver and signs of hepatic failure, such as hyperbilirubinemia and coagulopathy. There was no evidence of viral hepatitis or biliary obstruction. We performed several sessions of ET in order to reduce the percentage of HbS to levels inferior to 30%, which was successfully accomplished. The patient had a complete recovery of hepatic function. This case has shown that ET is an effective treatment of SCIC and should be introduced early on the onset of this severe complication.