COVID-19 outcomes in sickle cell disease and sickle cell trait

Throughout the Coronavirus Disease 2019 (COVID-19) pandemic, understanding the effects of COVID-19 on persons with Sickle Cell Disease (SCD) and Sickle Cell Trait (SCT) has garnered interest. Patients with SCD diagnosed with COVID-19 utilize the emergency department and are hospitalized at significantly higher rates compared to the general population, with vaso-occlusive crisis and acute chest syndrome as the leading presentations. Whether SCD alone increases the likelihood of severe COVID-19 illness remains uncertain; however, potential risk factors for severe disease among patients with SCD include older age, frequent acute care visits for pain, haemoglobin SC disease, and pre-existing end-organ disease. SCT status may also influence COVID-19 outcomes, particularly among those with pre-existing co-morbidities. Corticosteroids in patients with SCD and COVID-19 should be used with extreme caution given strong associations between corticosteroid exposure and severe vaso-occlusive crisis, with prophylactic transfusion administered if corticosteroids are deemed necessary. Hydroxyurea may be protective in COVID-19.     

Splenic function in persons with sickle cell trait at moderately high altitude

We investigated the possibility that persons with sickle cell trait who reside chronically at moderately high altitude might develop impaired splenic reticuloendothelial function. Seventeen healthy young black men with sickle trait who had lived at greater than or equal to 1,609 m for greater than or equal to 10 years participated in the study along with 25 matched control subjects with normal hemoglobin. Splenic function was assessed by radionuclide liver-spleen scanning and by red cell pit counts. No evidence of impaired splenic function was found in the sickle trait group. The data suggest that long-term residence at moderately high altitude does not place persons with sickle cell trait at risk for splenic dysfunction.     

Splenic sequestration associated with sickle cell trait and hereditary spherocytosis.

Coexistence of sickle cell trait and hereditary spherocytosis (HS) is unusual, and only 16 cases have been reported in the literature. These patients have the same clinical and hematological features as individuals having HS alone. We report a serious complication, acute splenic sequestration crisis (ASSC), occurring in two patients with sickle cell trait and HS. One patient experienced four episodes of ASSC during an 11-year span, while the other had two episodes of this complication during a 4-year period. Red blood cell studies and membrane protein analysis confirmed the diagnosis of HS as a consequence of spectrin deficiency. Splenectomy resulted in marked clinical and hematological improvement in both patients. Histological examination of spleens following splenectomy confirmed that significant erythrostasis and sickling had indeed occurred. ASSC can occur in patients with coexistence of sickle cell trait and HS, and this potentially life-threatening complication should be considered in this condition.     

Sickle cell trait in a white Jewish family presenting as splenic infarction at high altitude

We report the presence of sickle cell trait in several members of a white Jewish family. The trait was discovered when the propositus developed massive splenic infarction at high altitude. No erythrocyte markers characteristic of African ancestry were detected in any of the family members. This is the first bona fide documentation of sickle trait among white Jews.     

Coagulation changes in individuals with sickle cell trait

Sickle cell disorders, such as Hb SS and Hb SC, are associated with a hypercoagulable state that may contribute to the vaso-occlusive episodes observed in the disorders. To what extent increased coagulation activity occurs in individuals with sickle cell trait has had limited study. Because such information may help clarify clinical and pathologic findings that may occur in these individuals and may be useful in clarifying the hypercoagulable state in sickle cell disease, we have examined individuals with Hb AS to determine the extent that increased coagulation activity does occur. We measured d-dimers, thrombin-antithrombin (TAT) complexes, prothrombin fragment 1.2 (F1.2), absolute blood monocyte levels, proteins C and S, and isotypes of antiphospholipid antibodies in individuals with Hb AS and in matched controls (Hb AA). Results showed that d-dimers, TAT, and F1.2 were increased significantly above normal levels. Absolute blood monocyte levels were increased. The d-dimers, TAT, F1.2, and monocyte counts showed significant increasing trends through groups of increasing severity (Hb AA, Hb AS, Hb SC, and Hb SS). Our study shows that individuals with Hb AS have increased coagulation activity, with d-dimers, TAT, and F1.2 being consistent indicators. The measures of coagulation activity in Hb AS are lower than in patients with Hb SC and Hb SS disease. These results extend our previous observation that the degree of coagulation activation parallels the degree of disease severity among sickle cell genotypes. The findings suggest that monocytosis, with the possible expression of monocyte-derived tissue factor, and the associated hypercoagulable state are driven by disease severity.     

Splenic infarction associated with sorafenib use in a hepatocellular carcinoma patient

Sorafenib,a multitargeted tyrosine kinase inhibitor,has been shown to improve survival in patients with advanced hepatocellular carcinoma(HCC).As the clinical use of sorafenib increases,many adverse effects have been reported,such as hand-foot skin reaction,diarrhea,anorexia,asthenia,alopecia,weight loss,hypertension and arterial thromboembolism.However,there are no prior reports of splenic infarction as an adverse effect of sorafenib.Here,a case of splenic infarction in a patient with HCC who was treated w...     

Hemoglobin S levels in sickle cell trait individuals

Changes in Department of Defense regulations now permit persons with sickle cell trait to serve in all service branches. However, for purposes of the regulation, sickle cell trait is defined as 41% or less S hemoglobin. Our screening experience, based on 397 individuals with sickle cell trait, with quantitative scan of cellulose acetate electrophoretic sheets, indicates that 20-40% (depending on definition of terms) of individuals with sickle cell trait would be excluded by this criterion.     

Splenic infarction in a pregnant woman with systemic lupus erythematosus

Here we describe a 20-year-old pregnant woman with systemic lupus erythematosus who had high anticardiolipin antibodies and presented with splenic infarction.     

Impact of sickle cell trait on the thrombotic risk associated with non-O blood groups in northern Nigeria

Background

The non-O blood group is an established risk factor for deep vein thrombosis (DVT), while controversy surrounds the role of sickle cell trait (SCT) as a risk factor for DVT. We hypothesised that if SCT is a risk factor for DVT, individuals with non-O blood groups and SCT (Hb AS) would have a higher risk of DVT than their counterparts with non-O blood groups and normal haemoglobin phenotype (Hb AA).

Materials and methods

We retrospectively analysed the prevalence of SCT and non-O blood groups among 148 DVT patients with control subjects in order to determine the role of SCT as a risk factor for DVT and its impact on the risk of DVT among patients with non-O blood groups.

Results

In comparison with control subjects, DVT patients had significantly higher prevalences of SCT (35.1% vs 27.7%, p=0.04) and non-O blood groups (68.9% vs 45.9%, p=0.02). The odds ratios for DVT due to SCT, non-O blood groups with normal Hb phenotype (Hb AA) and non-O blood groups with SCT (Hb AS) were 1.3, 2.4 and 3.5, respectively.

Discussion

These results suggest that SCT by itself is a weak risk factor for DVT but it has the potential of escalating the DVT risk among patients with non-O blood groups. The combined effects of elevated clotting factors (non-O group effect) and increased clotting factor activation (SCT effect) were responsible for the escalated DVT risk among patients with co-inheritance of non-O blood groups and SCT. Co-inheritance of SCT and non-O blood group is, therefore, an important mixed risk factor for DVT. This should be taken into account when assessing DVT risk profiles of patients in Africa and other parts of the world where the SCT is prevalent.     

Myocardial infarction in sickle cell anemia

A review of the electrocardiograms (ECG) of 108 patients with sickle cell anemia found only 3 with patterns consistent with myocardial infarction. Two of the 3 patients with ECG infarct patterns had postmortem examination confirmation of the infarction. These two patients had no significant coronary atherosclerosis nor did the other six autopsied patients in the present series. Literature reports of postmortem examinations on patients with sickle cell anemia confirm the scarcity of coronary atherosclerosis and myocardial infarction in these patients. Forty of the 108 ECGs showed signs of left ventricular hypertrophy and 20 others had nondiagnostic ST and T wave abnormalities. Nine showed first degree AV block and four right bundle branch block.     

Acute renal infarction in sickle cell disease

End organ failure in sickle cell disease has classically been attributed to changes in the microvasculature. A case is reported in which sudden and complete loss of blood flow to the left kidney occurred during a painful crisis in a woman with homozygous SS disease. The findings are most consistent with occlusion of the renal artery.     

Dyspareunia is associated with chronic pain in premenopausal women with sickle cell disease

Objectives: Pain is common in women with sickle cell disease (SCD), but the prevalence of dyspareunia in this unique patient population is unknown. In this study, we sought to determine whether chronic pain is associated with an increased prevalence of dyspareunia in premenopausal women with SCD.

Methods: A cross-sectional study of premenopausal women with SCD was systematically assessed for symptoms of dyspareunia and chronic pain using a standard questionnaire. These results were correlated with each subject's clinical pain phenotype determined by a review of the patient's electronic medical record.

Results: Ninety-one premenopausal women with SCD were examined. Thirty-two percent of the women reported dyspareunia. Women with dyspareunia were more likely to have a history of chronic pain (90% versus 61%, p?=?.006), report more pain days per week (median (interquartile range): 6 (4–7) vs. 3 (0–7), p?=?.005)), and had a higher oral morphine equivalent dose (145 (45–226) mg vs. 60 (9–160) mg, p?=?.030). Using a multivariable classification tree analysis, number of days of pain experienced per week was an important predictor of dyspareunia (p?=?.001).

Conclusion: Dyspareunia is common in women with SCD, and more common in women with SCD and chronic pain. Providers should assess women with SCD for dyspareunia, especially those with a chronic pain syndrome.     

Erythrocyte type 1 equilibrative nucleoside transporter expression in sickle cell disease and sickle cell trait

Hypoxia-mediated red blood cell (RBC) sickling is central to the pathophysiology of sickle cell disease (SCD). The signalling nucleoside adenosine is thought to play a significant role in this process. This study investigated expression of the erythrocyte type 1 equilibrative nucleoside transporter (ENT1), a key regulator of plasma adenosine, in adult patients with SCD and carriers of sickle cell trait (SCT). Relative quantitative expression analysis of erythrocyte ENT1 was carried out by Western blot and flow cytometry. Patients with SCD with steady state conditions, either with SS or SC genotype, untreated or under hydroxycarbamide (HC) treatment, exhibited a relatively high variability of erythrocyte ENT1, but with levels not significantly different from normal controls. Most strikingly, expression of erythrocyte ENT1 was found to be significantly decreased in patients with SCD undergoing painful vaso-occlusive episode and, unexpectedly, also in healthy SCT carriers. Promoting hypoxia-induced adenosine signalling, the reduced expression of erythrocyte ENT1 might contribute to the pathophysiology of SCD and to the susceptibility of SCT individuals to altitude hypoxia or exercise to exhaustion.     

Red cell exchange in sickle cell disease

Red cell exchange transfusion is frequently of use in the management of patients with sickle cell disease either electively or therapeutically. Modern cell separators allow this procedure to be performed rapidly, effectively and safely. These machines have a number of advantages over manual exchange procedures. The patient remains isovolaemic, there is little loss of plasma or platelets, the procedure is relatively short and in elective circumstances can be performed on an outpatient basis. In this series 66 exchanges were performed on 21 patients with an overall increase in HbA of 70%. The COBE Spectra gave a mean increase in HbA of 77%, with the majority of patients achieving an HbA of > 90% post exchange. Automated redcell exchange was well tolerated by most patients, and adverse effects were limited to symptoms of hypocalcaemia which were easily treated, and to transfusion reactions. Cell separators can therefore be recommended for exchange transfusion in patients with sickle cell disease, who require an increase in HbA levels either prophylactically or therapeutically. They are safe, effective, easy and quick to use.