A study of the geographic distribution and associated risk factors of leg ulcers within an international cohort of sickle cell disease patients: the CASiRe group analysis

Controversies in the pathophysiology of leg ulcers in sickle cell disease

Patients with sickle cell disease (SCD) often experience painful vaso-occlusive crises and chronic haemolytic anaemia, as well as various acute and chronic complications, such as leg ulcers. Leg ulcers are characterized by their unpredictability, debilitating pain and prolonged healing process. The pathophysiology of SCD leg ulcers is not well defined. Known risk factors include male gender, poor social conditions, malnutrition and a lack of compression therapy when oedema occurs. Leg ulcers typically start with spontaneous pain, followed by induration, hyperpigmentation, blister formation and destruction of the epidermis. SCD is characterized by chronic haemolysis, increased oxidative stress and decreased nitric oxide bioavailability, which promote ischaemia and inflammation and consequently impair vascular function in the skin. This cutaneous vasculopathy, coupled with venostasis around the ankle, creates an ideal environment for local vaso-occlusive crises, which can result in the development of leg ulcers that resemble arterial ulcers. Following the development of the ulcer, healing is hindered as a result of factors commonly observed in venous ulceration, including venous insufficiency, oedema and impaired angiogenesis. All of these factors are modulated by genetic factors. However, our current understanding of these genetic factors remains limited and does not yet enable us to accurately predict ulceration susceptibility.

Sickle cell leg ulcer successfully managed by hyperbaric oxygen: a case report

Sickle cell leg ulcers (SCLUs) are usually chronic, painful, and devastating complications of sickle cell disease. Skin vaso-occlusion with compromised blood flow, chronic inflammation, and endothelial dysfunction is thought to be the underlying mechanism. It is usually slow to heal, and it may become chronic and superinfected. The management of SCLUs is usually challenging and requires a multidisciplinary team. Multiple systemic and local therapies have been tried in SCLU treatment. However, the outcome is variable: currently, there are no official recommendations for the best effective treatment. Herein, we report a 34-year-old male patient with non-transfusion-dependent sickle cell disease who was suffering from a chronic left ankle ulcer and was successfully managed with hyperbaric oxygen therapy, resulting in a complete resolution of this devastating complication.

Leg Ulcers in Sickle Cell Disease: A Multifactorial Analysis Highlights the Hemolytic Profile

Sickle cell disease (SCD) is characterized by the presence of the variant S hemoglobin (HbS). The homozygous genotype (HbSS) is sickle cell anemia (SCA), while the double heterozygous of HbS and HbC (HbSC) is defined as SC hemoglobinopathy. The pathophysiology is based on chronic hemolysis, inflammation, endothelial dysfunction, and vaso-occlusion, which results in vasculopathy and serious clinical manifestations. Sickle leg ulcers (SLUs) are cutaneous lesions around the malleoli frequent in 20% of Brazilian patients with SCD. SLUs present a variable clinical and laboratory pattern modulated by several characteristics that are not fully understood. Hence, this study aimed to investigate laboratory biomarkers and genetic and clinical parameters associated with the development of SLUs. This descriptive cross-sectional study included 69 SCD patients, 52 without SLU (SLU-) and 17 with active or previous SLU history (SLU+). The results showed a higher incidence of SLU in SCA patients and there was no observed association of α-3.7 Kb thalassemia in SLU occurrence. Alterations in NO metabolism and hemolysis were associated with clinical evolution and severity of SLU, in addition to hemolysis modulating the etiology and recurrence of SLU. Our multifactorial analyses demonstrate and extend the role of hemolysis driving the pathophysiological mechanism of SLU.

Factors Associated with Leg Ulcers in Adults with Sickle Cell Disease in Brazil

OBJECTIVE

To define the prevalence of leg ulcers and identify the clinical and laboratory factors associated with leg ulcers in adult participants.

METHODS

The authors conducted a cross-sectional study of 1,109 patients who were 18 years or older with SS or Sβ0-thalassemia genotypes from a Brazilian cohort. Investigators assessed the prevalence of factors associated with leg ulcers from 2013 to 2017.

RESULTS

The prevalence of leg ulcers was 21%. Increasing age (odds ratio [OR], 1.07; range, 1.06-1.09), male sex (OR, 2.03; range, 1.44-2.87), treatment with chronic transfusion therapy (OR, 1.88; range, 1.15-3.03), higher indirect bilirubin levels (OR, 1.48; range, 1.02-2.16), and low hemoglobin levels (OR, 2.17; range, 1.52-3.11) were associated with leg ulcers. Participants who self-reported as Black (OR, 6.75; range, 2.63-21.32), mixed (OR, 3.91; range, 1.55-12.20), and other/unknown (OR, 3.84; range, 1.04-15.24) were more likely to have leg ulcers compared with those who self-reported as White.

CONCLUSIONS

The prevalence of leg ulcers in this Brazilian cohort was higher than the prevalence reported in developed countries. Known factors such as age and male sex were corroborated. The increased bilirubin level and decreased hemoglobin levels among participants with leg ulcers support the hypothesis that hemolysis is correlated with leg ulcer pathogenesis. Self-reported black skin color was an independent predictor of leg ulcers and warrants further study to understand the etiology and implications of this finding.

Hemoglobin and End-Organ Damage in Individuals with Sickle Cell Disease

Background

Sickle cell disease (SCD) is an inherited, chronic, multifaceted blood disorder. Patients with SCD develop anemia, which has been associated with end-organ damage (EOD).

Objectives

This retrospective, observational, repeated-measures study systematically characterizes the relationship between hemoglobin (Hb) level and EOD in adolescent and adult patients with SCD.

Methods

The study population comprised patients with SCD aged ≥12 years with available Hb data from a US provider-centric health care database. For each patient, each Hb value over time was included as a separate observation. Study outcomes-the onset of any new EOD, including chronic kidney disease, pulmonary hypertension, stroke, and leg ulcer-were ascertained during the 1-year period after each Hb assessment. The association between Hb levels and risk of new EOD was estimated using multivariable generalized estimating equations.

Results

A total of 16,043 unique patients with SCD contributed 44,913 observations. Adjusted odds of any EOD during the 1-year follow-up were significantly lower with higher Hb level. Risk reductions with higher Hb levels for chronic kidney disease, pulmonary hypertension, and leg ulcer were comparable. The risk of new EOD was significantly lower among adolescent and adult patients with higher Hb levels.

Conclusions

In patients with SCD, higher Hb levels are associated with a reduced risk of developing EOD. Therapeutic strategies that result in higher Hb levels may offer clinical and economic value for patients with SCD. (Curr Ther Res Clin Exp. 2023; 84:XXX-XXX).

Clinical and laboratory characterization of adult sickle cell anemia patients in Kinshasa

BACKGROUND

Sickle cell anemia (SCA) is a monogenic hemoglobinopathy associated with severe acute and chronic complications, with the highest incidence worldwide in Sub-Saharan Africa. The wide variability in clinical manifestations suggest that a uniform response to hydroxurea may not be attained. In view of a potential treatment with hydroxyurea (HU), we assessed the variability of clinical and hematological manifestations in a cohort of adults with SCA in Kinshasa, capital of the DR Congo in Central Africa.

METHODS

A cross-sectional study was conducted in a hospital dedicated to SCA management in Kinshasa. Clinical history of patients was recorded, a complete physical examination performed. The diagnosis was confirmed by means of DNA analysis. A full blood count and hemolysis markers were measured. The severity of the disease was evaluated by means of a previously reported score.

RESULTS

The study group consisted of 166 genetically confirmed SCA patients. The SCA severity was mild in 28.9%, moderate in 64.5% and severe in 6.6%. The disease severity score increased with patient's age (p ≤ 0.001). The severity was higher in males compared to females (p = 0.012). In males, the severity score was correlated with the presence of priapism (p = 0.045), a manifestation not previously incorporated in the severity score. The severity score was inversely correlated with the fetal hemoglobin (HbF) rate (p = 0.005). Malnutrition (BMI <18.5 kg/m2) was present in 47% of patients and was related to the male sex, hip disease (aOR 3.11; p = 0.019) and severe phenotype (aOR 3.53; p = 0.012). Leg ulcers were more frequent in males than in females (p = 0.001; OR 24.3) and were correlated with the number of days of hospitalization (p = 0.029). Hip disease was related to the increasing age (p = 0.008).

CONCLUSION

In this selected, hospital-based populations of adults with SCA, severe disease was rare, which may be due to survival bias. However, two thirds had moderate severity of the disease, mostly with a low HbF, and they may benefit from HU treatment. In the Central-African setting the separation between vaso-occlusive and hyperhemolytic sub-phenotypes was not applicable.

Prevalence of people with sickle cell disease and leg ulcers in Brazil: Socioeconomic and clinical overview

Objective

To identify the prevalence of people with leg ulcers resulting from sickle cell disease, as well as to describe the clinical, social, economic, and demographic conditions of these people.

Method

Descriptive study, carried out at the Minas Gerais Hematology and Hemotherapy Center Foundation. The study population consisted of individuals over the age of 18 with a diagnosis of sickle cell disease in the State of Minas Gerais, Brazil. Data collection was performed from August 2019 to April 2020 through interviews. For the prevalence calculation, a census was taken of 5,379 people over the age of 18 with sickle cell disease, 77 of whom had active leg ulcers. Descriptive data analysis was performed using SPSS software (version 20.0, Chicago, IL, USA).

Results

The prevalence of people with leg ulcers in Minas Gerais, Brazil was 1.4%. Of the 72 respondents, the average age was 39 years (range 18–64 years), 41.7% were single, 48.6% said they were black, 84.7% lived in their own house, 38.9% were retired, 61.1% had an income of one minimum wage. The median years of education was 10.5, 50% cited the church as a place for leisure activities, 79.2% denied smoking. Regarding pain, the median score was 3, the median baseline hemoglobin was 7.7 g/dL, and 91.7% had the HbSS genotype. The median age of the first ulcer was 18 years, 77.8% of active ulcers were recurrent, and 59.7% had only one active ulcer. The median time of existence of the ulcer was 3 years. The ulcer prevented 80.6% of people from doing some activity. Prejudice was experienced by 48.6% of the participants.

Conclusion

The estimated prevalence of leg ulcers was lower than what it reported in the literature, however, the recurrence and the duration of ulcers were high. These findings bring reflection about the assistance to people with leg ulcer.

A Description of the Hemolytic Component in Sickle Leg Ulcer: The Role of Circulating miR-199a-5p, miR-144, and miR-126

Sickle leg ulcers (SLU) are malleoli lesions with exuberant hemolytic pathophysiology. The microRNAs are potential genetic biomarkers for several pathologies. Thereby, we aimed to assess the expression of circulating miR-199a-5p, miR-144, and miR-126 in association with hemolytic biomarkers in SLU. This cross-sectional study included 69 patients with sickle cell disease, 52 patients without SLU (SLU-) and 17 patients with active SLU or previous history (SLU+). The results demonstrated elevated expression of circulating miR-199a-5p and miR-144 in SLU+ patients while miR-126 expression was reduced. Circulating miR-199a-5p and miR-144 were associated with hemolytic biomarkers such as LDH, indirect bilirubin, AST, GGT, iron, ferritin, RBC, hemoglobin, and NOm, in addition to association with impaired clinical profile of SLU. Furthermore, in silico analyses indicated interactions of miR-199a-5p with HIF1A, Ets-1, and TGFB2 genes, which are associated with vasculopathy and reduced NO. In contrast, miR-126 was associated with an attenuating clinical profile of SLU, in addition to not characterizing hemolysis. In summary, this study demonstrates, for the first time, that hemolytic mechanism in SLU can be characterized by circulating miR-199a-5p and miR-144. The circulating miR-126 may play a protective role in SLU. Thus, these microRNAs can support to establish prognosis and therapeutic strategy in SLU.

Phenotypic characterisation and associations of leg ulcers in adult sickle cell patients

Sickle leg ulcer (SLU) occurs as a result chronic occlusion of the vasculature with consequent necrosis of the skin and subcutaneous tissue usually in proximity of the malleoli. The description of clinical associations and the simultaneous occurrence of SLU and other complications of SCD compared to the non-SLU patients was the aim of this work. A total of 272 (60.8% males and 39.2% females) patients were captured during this time period out of which 68 (51 males and 17 females) had SLU out of whom 20 patients had bilateral leg ulcers. Prevalence of SLU was 25% and the median age of patients was 25 years, frequency of crisis 2 per annum and 44 (74.6%) had been transfused in the past. Median Hb of the group was 7.6 g/dl and 25% had values lower than 6.5. The occurrence of other complications in SLU patients was as follows; 10 had AVN, 9 priapism, 8 had osteomyelitis, 6 nephropathy, stroke 2, osteoarthritis 4 and cholelithiasis 4. There was a significant relationship between the occurrence of SLU and gender of the patient being more in 67males-Likelihood ratio 4.610 (p = 0.032) and the occurrence of pulmonary hypertension-Likelihood ratio 4.762 (p = 0.029). There was no significant association between the occurrence of SLU and other complications of SCD. Leg ulcer patients have a median age of 25 years with a prevalence of 25% but do not necessarily show other features of severe disease phenotypes. SLU patients were more likely to develop pulmonary hypertension. Further studies on impact of environmental factors on the occurrence of SLU are needed to further evaluate its aetiology.

Global geographic differences in healthcare utilization for sickle cell disease pain crises in the CASiRe cohort

BACKGROUND

Sickle cell disease (SCD) is characterized by frequent, unpredictable pain episodes and other vaso-occlusive crises (VOCs) leading to significant healthcare utilization. VOC frequency is often an endpoint in clinical trials investigating novel therapies for this devastating disease.

PROCEDURE

The Consortium for the Advancement of Sickle Cell Research (CASiRe) is an international collaboration investigating clinical severity in SCD using a validated questionnaire and medical chart review standardized across four countries (United States, United Kingdom, Italy and Ghana).

RESULTS

This study, focused on pain crisis incidence and healthcare utilization, included 868 patients, equally represented according to age and gender. HgbSS was the most common genotype. Patients from Ghana used the Emergency Room/Day Hospital for pain more frequently (annualized mean 2.01) than patients from other regions (annualized mean 1.56 U.S.; 1.09 U.K.; 0.02 Italy), while U.K. patients were hospitalized for pain more often (annualized mean: U.K. 2.98) than patients in other regions (annualized mean 1.98 U.S.; 1.18 Ghana; Italy 0.54). Italy's hospitalization rate for pain (annualized mean: 0.57) was nearly 20 times greater than its emergency room/day hospital only visits for pain (annualized mean: 0.03). When categorized by genotype and age, similar results were seen.

CONCLUSIONS

Geographic differences in pain crisis frequency and healthcare utilization may correlate with variable organization of healthcare systems among countries and should be considered regarding trial design, endpoints, and analysis of results when investigating novel agents for clinical benefit.

Insights into the skin microbiome of sickle cell disease leg ulcers

Leg ulcers are estimated to occur in 1%-10% of North American patients with sickle cell disease (SCD). Their pathophysiology remains poorly defined, but as with other chronic wounds, it is hypothesised that the microbial milieu, or microbiome, contributes to their healing and clinical outcomes. This study utilises 16S ribosomal RNA (rRNA) gene sequencing to describe, for the first time, the microbiome of the SCD leg ulcer and its association with clinical factors. In a cross-sectional analysis of 42 ulcers, we recovered microbial profiles similar to other chronic wounds in the predominance of anaerobic bacteria and opportunistic pathogens including Staphylococcus, Corynebacterium, and Finegoldia. Ulcers separated into two clusters: one defined by predominance of Staphylococcus and smaller surface area, and the other displaying a greater diversity of taxa and larger surface area. We also find that the relative abundance of Porphyromonas is negatively associated with haemoglobin levels, a key clinical severity indicator for SCD, and that Finegoldia relative abundance is negatively associated with CD19+ B cell count. Finally, ratios of Corynebacterium:Lactobacillus and Staphylococcus:Lactobacillus are elevated in the intact skin of individuals with a history of SCD leg ulcers, while the ratio of Lactobacillus:Bacillus is elevated in that of individuals without a history of ulcers. Investigations of the skin microbiome in relation to SCD ulcer pathophysiology can inform clinical guidelines for this poorly understood chronic wound, as well as enhance broader understanding about the role of the skin microbiome in delayed wound healing.

Common, But Neglected: A Comprehensive Review of Leg Ulcers in Sickle Cell Disease

OBJECTIVE

To compile available evidence to better understand the management of leg ulcers in sickle cell disease (SCD), as well as describe potential therapeutic steps that may be required to improve the quality of life of patients with SCD leg ulcers.

DATA SOURCES

MEDLINE, PubMed, EMBASE, and Web of Science databases.

STUDY SELECTION

A comprehensive search was conducted to retrieve relevant studies using the keywords "sickle cell disease and leg ulcer," "ulcer treatments, diagnosis and sickle cell," and "wound sickle cell." Studies published through July 2020 were included.

DATA EXTRACTION

Two independent authors selected all studies that assessed the relationship between leg ulcer and SCD identified from online databases.

DATA SYNTHESIS

The authors have summarized updated information on pathophysiology (vasculopathy linked to chronic hemolysis and endothelial dysfunction), diagnosis, and available treatment options to unravel the dermohematologic connection between leg ulcers and SCD.

CONCLUSIONS

It is the authors' hope that this detailed discussion of the information available on leg ulcers and SCD will lead to a better appreciation of this clinical problem by the clinicians and researchers and in turn have a long-term positive effect on the quality of life of patients with SCD. Researchers should design new trials considering these insights and potential therapeutic approaches based on current knowledge.

PROFILE OF WOMEN WITH LEG ULCERS DUE TO SICKLE CELL DISEASE

Objective: to characterize the profile of women with leg ulcers resulting from sickle cell disease treated at a public health institution in Brazil. Method: historical cohort study conducted in the outpatient sector with a sample of women with sickle cell disease and leg ulcer, followed from 1998 to 2014. The data were extracted from the medical record and included sociodemographic, clinical and ulcer-related variables, and underwent descriptive statistical analysis. Results: of the 17 women, 64.7% were cured, 58.8% were aged between 30 and 39 years, 64.7% declared themselves brown, 70.6% were without partners, 41.2% had incomplete elementary education, 52, 9% had an income of 2 to 3 minimum wages, 70.6% were eutrophic and 82.4% used vitamin supplements. Women had a total of 29 ulcers, 52.9% had a single ulcer, 41.4% were located in the malleolar region, 55.17% were between 2 and 36 months, all classified as stage 3. The treatment was with coverings and Unna’s boot. Conclusion: the women received care from specialist nurses and most were cured with up to eight months of follow-up, which required a nursing consultation, including clinical evaluation, topical treatment and application of compression therapy.

PERFIL DE MULHERES COM ÚLCERAS DA PERNA DECORRENTES DE DOENÇA FALCIFORME

Objetivo:caracterizar o perfil de mulheres com úlceras da perna decorrentes da doença falciforme atendidas em uma instituição pública de saúde do Brasil. Método: estudo de coorte histórica realizado no setor ambulatorial com amostra de mulheres com doença falciforme e úlcera da perna, acompanhadas de 1998 a 2014. Os dados foram extraídos do prontuário e contemplaram variáveis sociodemográficas, clínicas e relacionadas à úlcera, e passaram por análise estatística descritiva. Resultados: das 17 mulheres, 64,7% obtiveram cura, 58,8% tinham idade entre 30 e 39 anos, 64,7% se autodeclaram pardas, 70,6% estavam sem parceiros, 41,2% possuíam ensino fundamental incompleto, 52,9% tinham renda de 2 a 3 salários mínimos, 70,6% eram eutróficas e 82,4% faziam uso de suplementos vitamínicos. As mulheres apresentaram o total de 29 úlceras, 52,9% tinham úlcera única, 41,4% localizadas na região maleolar, 55,17% com existência entre 2 e 36 meses, todas classificadas em estágio 3. O tratamento foi com coberturas e bota de Unna. Conclusão: as mulheres receberam cuidados de enfermeiros especialistas e a maioria obteve a cura com até oito meses de acompanhamento que demandou a consulta de enfermagem, contemplando a avaliação clínica, o tratamento tópico e aplicação da terapia de compressão.

Age of first pain crisis and associated complications in the CASiRe international sickle cell disease cohort

Pain is a hallmark of Sickle Cell Disease (SCD) affecting patients throughout their life; the first pain crisis may occur at any age and is often the first presentation of the disease. Universal newborn screening identifies children with SCD at birth, significantly improving morbidity and mortality. Without early screening, diagnosis is generally made after disease manifestations appear. The Consortium for the Advancement of Sickle Cell Research (CASiRe) is an international collaborative group evaluating the clinical severity of subjects with SCD using a validated questionnaire and medical chart review, standardized across 4 countries (United States, United Kingdom, Italy and Ghana). We investigated the age of first pain crisis in 555 sickle cell subjects, 344 adults and 211 children. Median age of the first crisis in the whole group was 4 years old, 5 years old among adults and 2 years old among children. Patients from the United States generally reported the first crisis earlier than Ghanaians. Experiencing the first pain crisis early in life correlated with the genotype and disease severity. Early recognition of the first pain crisis could be useful to guide counseling and management of the disease.

Enhanced Hypercoagulability in Sickle Cell Anaemia Patients with Chronic Leg Ulcers

Sickle Cell Anaemia (SCA) is associated with a hypercoagulable state resulting in a predisposition to venous thromboembolism. With improvements in the quality of care, more patients with SCA survive into adulthood with an associated increase in the frequency of end-organ damage and chronic complications such as chronic leg ulcers (CLUs). These ulcers rarely occur in the first decade of life and are recurrent, painful, and slow-to-heal. This study tested the hypothesis that coagulation is enhanced in SCA patients with CLU. 145 participants (50 SCA with CLU, 50 SCA without CLU, and 45 with haemoglobin AA) were assessed to determine their coagulation profile using selected tests of coagulation. The SCA with the CLU group had the lowest mean haemoglobin (Hb) concentration. SCA patients with and without CLUs had elevated mean platelet counts, shorter mean aPTT, and marginally prolonged mean PT  compared to HbAA patients. SCA with CLUs patients had a significantly shortened aPTT than those without CLUs (p = 0.035) and HbAA (p = 0.009). There were significant differences in the mean PT between SCA with CLUs patients and HbAA (p = 0.017); SCA without CLU and HbAA (p = 0.014). SCA with and without CLUs patients had higher mean D-dimer levels compared to HbAA. There was a negative correlation between Hb concentration and duration of CLU (r = -0.331, p = 0.021). In conclusion, our study demonstrates a heightened hypercoagulability in SCA patients with CLUs. We did not test for platelet activation, and it is not clear what role, if any, the enhanced hypercoagulability plays in the pathogenesis of CLUs in SCA. It will be useful to ascertain if antiplatelet agents or/and anticoagulants quicken the healing of CLUs in SCA patients.

Prevalence and Predictive Factors for Leg Ulcers in Sickle Cell Disease Patients in Saudi Arabia: A Cross-Sectional Observational Study

Introduction

Saudi Arabia has a high prevalence of sickle cell disease (SCD). Leg ulceration is one of the complications associated with SCD. There is a gap in the literature in regard to the prevalence of leg ulcers among SCD patients in Saudi Arabia.

Objectives

The primary objective of this study was to evaluate the lifetime prevalence of leg ulcers in SCD patients in our population and to study the predictive factors of leg ulcers by using sociodemographic factors, clinical manifestations of SCD, and other relevant factors like hydroxyurea.

Methods

A cross-sectional study design was utilized. Data collection was done using an electronic survey to collect self-reported information for the prevalence of leg ulcers and possible associated factors. The survey was distributed using social media platforms. Chi-square test was used to test for the presence of an association between having leg ulcers and sociodemographic variables as well as SCD related history. Furthermore, binary logistic regression was utilized to determine factors predicting the incidence of leg ulcers among SCD.

Results

A total of 790 valid responses were included in the study. Among these, 646 were included in the analysis of leg ulcers prevalence. From them, 52 (8%) SCD patients reported a history of leg ulcers. The male to female ratio was (9.7% vs 7.2%). The age group most affected by leg ulcers was those older than 50 (16.7%). There was no significant association between a history of leg ulcers and sociodemographic variables. The only predictive factors for leg ulcers were having six to eight vaso-occlusive crises per month and having more than eight vaso-occlusive crises per month.

Conclusion

Leg ulcers among SCD patients in Saudi Arabia were considerably prevalent (8%). There was no statistically significant correlation between leg ulceration and sociodemographic variables. Leg ulcers were more likely in patients with a history of highly frequent vaso-occlusive crises. No association was found between the incidence of leg ulcers and other complications of sickle cell disease or hydroxyurea.