Traditional laboratory measures of cardiovascular risk in hereditary spherocytosis

Cerebrovascular Complications of Anemia

PURPOSE OF THE REVIEW

Anemia has been called the fifth cardiovascular risk factor. It is one of the most prevalent pathologies worldwide. In this article, we aimed to perform a narrative review of the main cerebrovascular complications of anemia and its influence on stroke prognosis.

RECENT FINDINGS

Both hypoproliferative anemia (thalassemia, iron deficiency anemia, etc.) and hyperproliferative anemia (sickle cell disease, paroxysmal nocturnal hemoglobinuria, hereditary spherocytosis, etc.) are associated to cerebrovascular disease ranging from transient ischemic attack to ischemic stroke and hemorrhagic stroke with both intraparenchymal hemorrhage and subarachnoid hemorrhage or cerebral venous thrombosis. Anemia is associated to a worse prognosis in patients with cerebrovascular disease In some cases, like sickle cell disease, pathophysiological mechanisms and therapeutic guidelines are well established, while in others, due to their rarity, there are still lack of robust data. More studies are needed to clarify how the prognosis of stroke patients with anemia could be improved.

The hemostasis system in children with hereditary spherocytosis

INTRODUCTION

Patients with hereditary spherocytosis (HS) are characterized by having an increased risk for thrombosis. An early manifestation of thrombotic complications can occur even in childhood, especially after surgery. Hypercoagulability can be associated with hemolytic crises.

AIM

The aim of this study was to investigate the hemostatic state in children with HS using global hemostasis assays.

METHODS

The hemostatic status of 62 children (38 boys and 24 girls; age range: 0.5 to 17 years) with HS during and without hemolytic crisis was assessed using clotting times (APTT, TT, and PR), fibrinogen and D-dimer levels, and global hemostasis, thromboelastography (TEG) and thrombodynamics (TD) assays. One hundred and two healthy children undergoing annual medical examination were enrolled as a control group.

RESULTS

TEG and TD parameters were increased in the children with HS compared to the control group (60 ± 5 mm vs. 53 ± 4 mm, p < 0.05 for TEG maximum amplitude; 28 ± 3 μm/min vs. 24 ± 2 μm/min, p < 0.05 for TD clot growth rate), while APTT, TT and PR were not significantly different between the two groups. Patients with HS were divided into 2 groups: those during hemolytic crisis (28 patients) and those without hemolytic crisis (34 patients). TEG and TD parameters were increased in those during hemolytic crisis compared to the steady state HS group (62 ± 5 mm vs. 57 ± 4 mm, p < 0.05 for TEG maximum amplitude; 31 ± 4 μm/min vs. 26 ± 3 μm/min, p < 0.05 for TD clot growth rate). The D-dimer levels were increased in 4 HS patients, for whom the activation of blood clotting was noted. Fibrinogen levels were decreased in patients with HS compared to the control group (2.1 ± 0.4 mg/ml vs. 2.6 ± 0.4 mg/ml, p < 0.05). Other tests were within the reference ranges for both groups.

CONCLUSIONS

The global hemostasis tests TEG and TD revealed hypercoagulability in patients with HS. More dramatic changes were observed in patients experiencing a hemolytic crisis.

Splenectomy had no significant impact on lipid metabolism and atherogenesis in Apoe deficient mice fed on a severe atherogenic diet

BACKGROUND

For a long time, our major understanding of the spleen is to function as a blood filter for the removal of aged erythrocytes and circulating microorganisms. Splenectomy, therefore, has been widely performed in case of trauma and a variety of hematologic disorders. Although some studies have indicated an increased rate of developing hyperlipidemia and atherosclerotic cardiovascular diseases in splenectomized patients, our recognition of the splenic regulation on lipid metabolism and atherogenesis is still lacking. Here we explored this issue in Apoe deficient (Apoe-/-) mice fed on an atherogenic diet containing 0.5% cholesterol and 20% fat.

METHODS

7-week-old male Apoe-/- mice were randomly divided into splenectomy group and sham operation group. After 1-week recovery from the surgery, mice were subjected to the atherogenic diet for the next 8 weeks.

RESULTS

The atherogenic diet induced a severe hypercholesterolemia (about 1500 mg/dl), steatohepatitis and accelerated atherogenesis in the Apoe-/- mice. Splenectomy, compared to sham operation, did not alter plasma lipid levels or lipoprotein profiles; it also did not alter hepatic or adipose lipid deposition. Meanwhile, splenectomy did not alter atherosclerotic plaque burden or composition; it also did not alter aortic gene expression associated with macrophage inflammatory responses.

CONCLUSIONS

Our data suggested that splenectomy had no significant impacts on lipid metabolism and atherogenesis in Apoe-/- mice fed on a severe atherogenic diet.

Effect of total splenectomy in the lipid profile in mice

PURPOSE

To analyze total splenectomy effect on the lipid profile - total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), very-low-density lipoprotein cholesterol (VLDL) and triglycerides levels, in Balb/c mice.

METHODS

Thirty Balb/c male mice, one (1) month old and average weight 26.2g ± 4.0 were used in the experiment. They were distributed into three groups of 10 animals each: a control group (non-operated), a simulation group (spleen manipulation) and the splenectomy group. The animals were subjected to blood sampling to measure plasma lipid levels, at three different times: before surgery, days 30 and 75 of the experiment.

RESULTS

Increased total cholesterol and LDL were observed in the control group from the start to end of the experiment. The simulation group showed increased rates of VLDL and triglycerides at the 30th and 75th days. Splenectomized animals showed no significant change.

CONCLUSION

Total splenectomy did not induce increased plasma lipids levels of in Balb/c mice.

Peter S, Sharma M, Davidoff AM, Nottage K, Bernabe K, Wilson DB, Dutta S, Glader B, Crary SE, Dassinger MS, Dunbar L, Islam S, Kumar M, Rescorla F, Bruch S, Campbell A, Austin M, Sidonio R, Blakely ML. Clinical outcomes of splenectomy in children: report of the splenectomy in congenital hemolytic anemia registry

The outcomes of children with congenital hemolytic anemia (CHA) undergoing total splenectomy (TS) or partial splenectomy (PS) remain unclear. In this study, we collected data from 100 children with CHA who underwent TS or PS from 2005 to 2013 at 16 sites in the Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium using a patient registry. We analyzed demographics and baseline clinical status, operative details, and outcomes at 4, 24, and 52 weeks after surgery. Results were summarized as hematologic outcomes, short-term adverse events (AEs) (≤30 days after surgery), and long-term AEs (31-365 days after surgery). For children with hereditary spherocytosis, after surgery there was an increase in hemoglobin (baseline 10.1 ± 1.8 g/dl, 52 week 12.8 ± 1.6 g/dl; mean ± SD), decrease in reticulocyte and bilirubin as well as control of symptoms. Children with sickle cell disease had control of clinical symptoms after surgery, but had no change in hematologic parameters. There was an 11% rate of short-term AEs and 11% rate of long-term AEs. As we accumulate more subjects and longer follow-up, use of a patient registry should enhance our capacity for clinical trials and engage all stakeholders in the decision-making process.

Mechanisms linking red blood cell disorders and cardiovascular diseases

The present paper aims to review the main pathophysiological links between red blood cell disorders and cardiovascular diseases, provides a brief description of the latest studies in this area, and considers implications for clinical practice and therapy. Anemia is associated with a special risk in proatherosclerotic conditions and heart disease and became a new therapeutic target. Guidelines must be updated for the management of patients with red blood cell disorders and cardiovascular diseases, and targets for hemoglobin level should be established. Risk scores in several cardiovascular diseases should include red blood cell count and RDW. Complete blood count and hemorheological parameters represent useful, inexpensive, widely available tools for the management and prognosis of patients with coronary heart disease, heart failure, hypertension, arrhythmias, and stroke. Hypoxia and iron accumulation cause the most important cardiovascular effects of sickle cell disease and thalassemia. Patients with congenital chronic hemolytic anemia undergoing splenectomy should be monitored, considering thromboembolic and cardiovascular risk.

Risk factors for thromboembolism and pulmonary artery hypertension following splenectomy in children with hereditary spherocytosis

BACKGROUND

The aim was to study risk-factors for vascular thrombosis and incidence of pulmonary artery hypertension (PAH) in splenectomized children with hereditary spherocytosis (HS) at a single center.

PROCEDURE

Pre- and post-splenectomy hemoglobin and platelet counts were recorded. Post-splenectomy lipid-profile, fibrinogen, D-dimer, CRP and anti-coagulant-protein levels were compared to established controls. Echo-Doppler was performed for PAH.

RESULTS

Twenty-six children with HS had undergone splenectomy; the mean age at surgery was 7.9 ± 3.7 years. Nineteen of the 26 were prospectively investigated at a median duration of 4.5 years (range: 4 months to 19 years) following splenectomy. Thrombocytosis was observed in 19 (73%), whereas no patient had erythrocytosis at the last follow-up visit. Total cholesterol, LDL-C, HDL-C, and triglyceride levels were not deranged (P ≥ 0.3). Mean CRP levels (males: 2.8 ± 0.5; females: 2.1 ± 0.5 mg/L) were significantly higher than described for normal children (P < 0.001). Six (23%) patients had a positive D-dimer assay. Protein S, anti-thrombin-III and fibrinogen were in range. A single patient had a borderline low protein C activity. Lupus anticoagulant and anti-cardiolipin antibody assays were negative. The mean tricuspid regurgitant jet velocity (TRJV) was 1.8 ± 0.55 meter per second (range: 0-2.4). None had a TRJV ≥2.5 meter per second to suggest PAH.

CONCLUSIONS

There was no evidence of PAH, dyslipidemia, elevation of fibrinogen or a reduction in anti-coagulant proteins, at a median follow-up duration of 4.5 years following splenectomy in children with HS. However, elevated CRP level (42%), persistent thrombocytosis (73%) and elevated D-dimer levels (23%) were observed. These have been recognized as risk factors for cerebrovascular and coronary heart disease.

Comparative effectiveness of different types of splenectomy for children with congenital hemolytic anemias

OBJECTIVE

To compare the effectiveness of different types of splenectomy in children with congenital hemolytic anemias.

STUDY DESIGN

We constructed key questions that addressed outcomes relevant to clinicians and families on effects of partial or total splenectomy, including hematologic effect, splenic function, and the risk of adverse events. We identified from Pubmed and Embase 703 studies that evaluated different types of splenectomy and accepted 93 studies that satisfied entry criteria. We graded the quality of each report and summarized the overall strength of research evidence for each key question.

RESULTS

We did not identify any randomized clinical trials. All types of splenectomy have favorable clinical outcomes in most diseases. We did not identify any hematologic advantage of laparoscopy compared with laparotomy. Adverse events are uncommon in most studies and are minimized with use of laparoscopy.

CONCLUSIONS

There is a need for randomized clinical trials and improved data collection of different types of splenectomy in congenital hemolytic anemias. Outcomes studied should address the concerns of families and clinicians to assess the risks and benefits of various treatments.