Acute leukemia in a patient with sickle-cell anemia treated with hydroxyurea

Sickle cell disease and acute leukemia: one case report and an extensive review

Population-based studies and case reports suggest that there may be an increased risk of acute leukemia associated with sickle cell disease (SCD). Following the description of a new case report, an extensive review of the literature identified 51 previously described cases. Most cases study showed myelodysplastic features confirmed, when available, by genetic markers such as chromosome 5 and/or chromosome 7 abnormalities and TP53 gene mutations. The increased risk of leukemogenesis is certainly multifactorial and related to the pathophysiologic mechanisms of the clinical manifestations of SCD. Chronic hemolysis and secondary hemochromatosis may cause increased chronic inflammation, resulting in persistent marrow stress, which could potentially compromise the genomic stability of the hematopoietic stem cells generating genomic damage and somatic mutations over the course of SCD and its treatment, resulting in a clone that led to acute myeloid leukemia.

Pure Erythroid Leukemia in a Sickle Cell Patient Treated with Hydroxyurea

We present a very rare case of pure erythroid leukemia arising in a young patient with sickle cell disease being treated with hydroxyurea for almost 5 years. Diagnosing and managing this rare condition has been a challenge and the majority of patients with pure erythroid leukemia have a very poor prognosis with survival in months despite treatment. This form of leukemia could be therapy related and in our case, hydroxyurea may have been responsible for the development of this aggressive condition.

Myeloid neoplasms in the setting of sickle cell disease: an intrinsic association with the underlying condition rather than a coincidence; report of 4 cases and review of the literature

Myeloid neoplasms occasionally occur in patients with sickle cell disease, and the underlying connection between the two diseases is unclear. Herein, we retrospectively analyzed four cases of sickle cell disease patients who developed myeloid neoplasm. Age at time of diagnosis ranged from 27 to 59 years with a median of 35.5 years. Two patients were treated with hydroxyurea and the other two with supportive care alone, with one out of the four patients receiving additional treatment with hematopoietic stem cell transplant. Three patients presented with leukocytosis, and the remaining patient presented with pancytopenia. Two patients were diagnosed with myelodysplastic syndrome/myeloproliferative neoplasm, one with myelodysplastic syndrome, and the other with acute myeloid leukemia. All four cases demonstrated certain degrees of myelodysplasia and complex cytogenetic abnormalities with - 7/7q- and/or - 5/5q- or with 11q23 (KMT2A) rearrangement. This cytogenetic profile resembles that seen in therapy-related myeloid neoplasm, suggesting that myeloid neoplasm in the setting of sickle cell disease may represent a subcategory of the disease distinct from de novo myeloid neoplasm in general. Extensive literature review further demonstrates this similarity in cytogenetic profile, as well as in other associated pathologic features. Potential etiology includes therapy for sickle cell disease, disease-related immunomodulation, or disease-related chronic inflammation. We hypothesize that constant hematopoietic hyperplasia, stimulated by a hemolysis-induced cytokine storm, may increase the chance of somatic mutations/cytogenetic aberrations, resulting in transformation of myeloid precursors. This group of myeloid neoplasms seems to herald a dismal clinical outcome, with median survival <1 year, although the exact pathogenesis and biology of the disease remain to be investigated by large cohorts in future studies.

Occurrence of acute myeloid leukemia in hydroxyurea-treated sickle cell disease patient

Hydroxyurea (HU) has been widely used in sickle cell disease. Its potential long-term risk for carcinogenesis or leukemogenic risk remains undefined. Here, we report a 26 y old African-American female with Sickle Cell Disease (SCD) who developed refractory/relapsed acute myeloid leukemia (AML) 6 months after 26 months of HU use. That patient's cytogenetics and molecular genetics analyses demonstrated a complex mutation profile with 5q deletion, trisomy 8, and P53 deletion (deletion of 17p13.1). P53 gene sequence studies revealed a multitude of somatic mutations that most suggest a treatment-related etiology. The above-mentioned data indicates that the patient may have developed acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) as a direct result of HU exposure.

Development of myelodysplastic syndrome and acute myeloid leukemia 15 years after hydroxyurea use in a patient with sickle cell anemia

We report a 41 year old male with sickle cell disease who developed a myelodysplastic syndrome and acute myeloid leukemia with complex karyotype involving chromosomes 5, 7 and 17 after 15 years of hydroxyurea treatment. He responded poorly to induction chemotherapy with cytarabine/idarubicin followed by high dose cytarabine and succumbed to neutropenic sepsis. Multiple systematic reviews, observational studies and clinical trials were conducted to identify the toxicity profile of hydroxurea. Only six cases of leukemia/myelodysplastic syndrome were identified in patients with sickle cell anemia treated with hydroxyurea. Subsequently, it was concluded that hydroxyurea is not leukemogenic. However, it was noted that most of the published studies had only up to 9 years of follow-up. Our patient was started on hydroxyurea in 1990, before the widespread use of the drug and took hydroxyurea for 15 years. His presentation may reflect an outcome otherwise not yet observed because of the short follow-up of prior studies. We believe that the leukemogenic risk of hydroxyurea should be discussed with the patients and their families. Studies evaluating the adverse effects of hydroxyurea should have longer follow-up before definitive conclusions are drawn.

Current strategies for the management of children with sickle cell disease

Children with sickle cell disease may present to doctors anywhere in the world. In developed countries, neonatal screening allows early identification and management of the disease, mostly through daily antibioprophylaxis, immunizations and education of the parents. Stroke prevention relies on the detection of high-risk patients by annual transcranial Doppler ultrasonography from 2 to 16 years of age. Annual check-ups aim to detect early organ deficiencies. The most frequent complications are pain, infections and acute anemia; they may occur in combination. Approximately 10% of children have severe sickle cell disease that may require chronic blood transfusion, hydroxyurea or hematopoietic stem cell transplantation. Comprehensive management programs have dramatically increased survival, and most patients now reach adulthood.

A critical review of anagrelide therapy in essential thrombocythemia and related disorders

Thrombocytosis is a common clinical problem and it represents either a primary myeloid disorder (a clonal process) or a reactive phenomenon. While reactive thrombocytosis is often inconsequential, clonal thrombocytosis may require cytoreductive therapy to prevent thrombohemorrhagic complications. In this regard, a controlled clinical trial has previously demonstrated the efficacy of hydroxyurea in reducing the risk of thrombosis in high-risk patients with essential thrombocythemia (ET). Despite the absence of similar evidence for clinical benefit, the platelet-lowering agent anagrelide has been widely used in both ET and polycythemia vera (PV) and recent reports of serious side-effects suggest that such practice might be detrimental to patients. In the current review we provide basic drug information as well as a critical assessment of anagrelide treatment in ET and related disorders.

Hydroxyurea for sickle cell disease: a systematic review for efficacy and toxicity in children

CONTEXT

Hydroxyurea is the only approved medication for the treatment of sickle cell disease in adults; there are no approved drugs for children.

OBJECTIVE

Our goal was to synthesize the published literature on the efficacy, effectiveness, and toxicity of hydroxyurea in children with sickle cell disease.

METHODS

Medline, Embase, TOXLine, and the Cumulative Index to Nursing and Allied Health Literature through June 2007 were used as data sources. We selected randomized trials, observational studies, and case reports (English language only) that evaluated the efficacy and toxicity of hydroxyurea in children with sickle cell disease. Two reviewers abstracted data sequentially on study design, patient characteristics, and outcomes and assessed study quality independently.

RESULTS

We included 26 articles describing 1 randomized, controlled trial, 22 observational studies (11 with overlapping participants), and 3 case reports. Almost all study participants had sickle cell anemia. Fetal hemoglobin levels increased from 5%-10% to 15%-20% on hydroxyurea. Hemoglobin concentration increased modestly (approximately 1 g/L) but significantly across studies. The rate of hospitalization decreased in the single randomized, controlled trial and 5 observational studies by 56% to 87%, whereas the frequency of pain crisis decreased in 3 of 4 pediatric studies. New and recurrent neurologic events were decreased in 3 observational studies of hydroxyurea compared with historical controls. Common adverse events were reversible mild-to-moderate neutropenia, mild thrombocytopenia, severe anemia, rash or nail changes (10%), and headache (5%). Severe adverse events were rare and not clearly attributable to hydroxyurea.

CONCLUSIONS

Hydroxyurea reduces hospitalization and increases total and fetal hemoglobin levels in children with severe sickle cell anemia. There was inadequate evidence to assess the efficacy of hydroxyurea in other groups. The small number of children in long-term studies limits conclusions about late toxicities.

Systematic review: Hydroxyurea for the treatment of adults with sickle cell disease

BACKGROUND

Hydroxyurea is the only approved drug for treatment of sickle cell disease.

OBJECTIVE

To synthesize the published literature on the efficacy, effectiveness, and toxicity of hydroxyurea when used in adults with sickle cell disease.

DATA SOURCES

MEDLINE, EMBASE, TOXLine, and CINAHL were searched through 30 June 2007.

STUDY SELECTION

Randomized trials, observational studies, and case reports evaluating efficacy and toxicity of hydroxyurea in adults with sickle cell disease, and toxicity studies of hydroxyurea in other conditions that were published in English.

DATA EXTRACTION

Paired reviewers abstracted data on study design, patient characteristics, and outcomes sequentially and did quality assessments independently.

DATA SYNTHESIS

In the single randomized trial, the hemoglobin level was higher in hydroxyurea recipients than placebo recipients after 2 years (difference, 6 g/L), as was fetal hemoglobin (absolute difference, 3.2%). The median number of painful crises was 44% lower than in the placebo group. The 12 observational studies that enrolled adults reported a relative increase in fetal hemoglobin of 4% to 20% and a relative reduction in crisis rates by 68% to 84%. Hospital admissions declined by 18% to 32%. The evidence suggests that hydroxyurea may impair spermatogenesis. Limited evidence indicates that hydroxyurea treatment in adults with sickle cell disease is not associated with leukemia. Likewise, limited evidence suggests that hydroxyurea and leg ulcers are not associated in patients with sickle cell disease, and evidence is insufficient to estimate the risk for skin neoplasms, although these outcomes can be attributed to hydroxyurea in other conditions.

LIMITATION

Only English-language articles were included, and some studies were of lower quality.

CONCLUSION

Hydroxyurea has demonstrated efficacy in adults with sickle cell disease. The paucity of long-term studies limits conclusions about toxicity.

Systematic review: Hydroxyurea for the treatment of adults with sickle cell disease

BACKGROUND

Hydroxyurea is the only approved drug for treatment of sickle cell disease.

OBJECTIVE

To synthesize the published literature on the efficacy, effectiveness, and toxicity of hydroxyurea when used in adults with sickle cell disease.

DATA SOURCES

MEDLINE, EMBASE, TOXLine, and CINAHL were searched through 30 June 2007.

STUDY SELECTION

Randomized trials, observational studies, and case reports evaluating efficacy and toxicity of hydroxyurea in adults with sickle cell disease, and toxicity studies of hydroxyurea in other conditions that were published in English.

DATA EXTRACTION

Paired reviewers abstracted data on study design, patient characteristics, and outcomes sequentially and did quality assessments independently.

DATA SYNTHESIS

In the single randomized trial, the hemoglobin level was higher in hydroxyurea recipients than placebo recipients after 2 years (difference, 6 g/L), as was fetal hemoglobin (absolute difference, 3.2%). The median number of painful crises was 44% lower than in the placebo group. The 12 observational studies that enrolled adults reported a relative increase in fetal hemoglobin of 4% to 20% and a relative reduction in crisis rates by 68% to 84%. Hospital admissions declined by 18% to 32%. The evidence suggests that hydroxyurea may impair spermatogenesis. Limited evidence indicates that hydroxyurea treatment in adults with sickle cell disease is not associated with leukemia. Likewise, limited evidence suggests that hydroxyurea and leg ulcers are not associated in patients with sickle cell disease, and evidence is insufficient to estimate the risk for skin neoplasms, although these outcomes can be attributed to hydroxyurea in other conditions.

LIMITATION

Only English-language articles were included, and some studies were of lower quality.

CONCLUSION

Hydroxyurea has demonstrated efficacy in adults with sickle cell disease. The paucity of long-term studies limits conclusions about toxicity.

[Hydroxyurea treatment in patients affected with sickle cell anemia: efficacy and safety]

Hydroxyurea is the unique drug having demonstrated an efficacy in preventing recurrences of painful crises, acute chest syndromes and in reducing transfusional needs in patients severely affected with sickle cell disease. However, there is a wide variation in the clinical response to hydroxyurea in sickle cell patients, with children generally experiencing greater benefits than adults. Short- and middle-term tolerances are good. Our uncertainties about long-term tolerance are mainly that we do not know the consequences of the drug on ulterior fertility in boys treated early and for long periods. Hydroxyurea has just been licensed for sickle cell adults and children in Europe. Its prescription for the moment must be restricted to severely affected patients, enrolled in long-term follow-up protocols.

Decreased transfusion needs associated with hydroxyurea therapy in Algerian patients with thalassemia major or intermedia

BACKGROUND

Studies of evolution of transfusion requirements in thalassemic patients treated with hydroxyurea have produced somewhat conflicting results, especially in patients with thalassemia major. Our aims were to determine the proportion of good responders to hydroxyurea in a population of transfusion-dependent thalassemic patients and to identify the factors associated with a decrease of transfusion needs.

STUDY DESIGN AND METHODS

Hydroxyurea treatment was initiated in 9 patients with thalassemia intermedia (TI) and 45 with thalassemia major (TM). Patients received transfusions when their hemoglobin (Hb) levels dropped below 6 g per dL. A decrease in annual transfusion requirements greater than 70 percent defined a good response, between 40 and 70 percent a partial response, and smaller than 40 percent no response.

RESULTS

The response was good in 8 (90%) patients with TI and 20 (44.5%) with TM, partial in 9 (20%) patients with TM, and absent in 1 (10%) with TI and 16 (35.5%) with TM. In TM patients, transfusion needs decreased by 56 percent over the first year of hydroxyurea treatment. By univariate analysis, a better response to hydroxyurea was associated with older age at the first transfusion (p = 0.02), higher prehydroxyurea Hb (p = 0.0004), codon 6(-A) mutation (p = 0.002), TI (p = 0.03), and history of splenectomy (p = 0.05). Xmn1-/- was associated with a worse response (p = 0.0001). By multivariate analysis, a better response was associated with the Xmn1 polymorphism (p = 0.008).

CONCLUSION

Hydroxyurea may be an alternative to transfusions for TI patients as well as for TM patients in countries that have limited blood supplies.

DNA damage in blood leukocytes of individuals with sickle cell disease treated with hydroxyurea

Hydroxyurea (HU) plays an important role in the treatment of patients with sickle cell disease (SCD). Although HU has been associated with an increased risk of leukemia in some patients with myeloproliferative disorders, the mutagenic and carcinogenic potential of HU has not been established. This study investigated levels of DNA damage using the alkaline (pH>13) comet assay to analyze peripheral blood leukocytes sampled from 28 patients with SCD treated with HU (SCHU) and from 28 normal individuals. The damage index (DI) in the SCHU group was significantly higher than in controls (p<0.05). Gender, smoking or age were not associated with DNA damage in controls or SCHU individuals. In the group of SCHU individuals, mean HU dose and DI were positively correlated, and individuals who received a mean dose of >20 mg/kg HU (DI=24.9+/-5.5) showed significantly more DNA damage than those who received < or =20 mg/kg HU (DI=14.6+/-1.8) (p<0.05). Individuals treated for > or =42 months (DI=23.1+/-4.2) showed significantly greater DNA damage than those treated for <42 months (13.6+/-1.9) (p<0.05). DI was inversely correlated with body mass index in the SCHU group.

Modern treatment of thalassaemia intermedia

The term thalassaemia intermedia includes a large spectrum of conditions of varying severity. Blood transfusion and chelation are necessary in some patients, especially during childhood, in order to promote growth and prevent bone deformities. Alloimunisation, however, is frequent and can be difficult to control. Splenectomy is usually needed at some time because of hypersplenism and mechanical encumbrance. Reactivation of HbF is possible only in a small proportion of patients: hydroxycarbamide (also known as hydroxyurea) appears to be the most effective drug for this purpose. Antioxidant agents, although theoretically useful, do not improve haemoglobin levels. Stem cell transplantation is an option limited to the severe forms. Gene therapy and other molecular approaches are subjects of intense study. Numerous complications, including pulmonary hypertension, thrombotic events, pseudoxanthoma elasticum and osteoporosis, have been described and all contribute to complicate the treatment of a disease that represents a significant burden for the patients and their families.

Parents' assessment of risk in sickle cell disease treatment with hydroxyurea

Hydroxyurea is the only medication shown to reduce the severity of sickle cell disease (SCD), but its long-term risks are unknown. Families of 58 children with SCD were interviewed on their perception of the potential risks of hydroxyurea treatment, and whether disease severity was a major factor in their treatment decision. Parents rated the severity of their child's SCD (86% as severe, 26% moderate, and 47% mild) and then the highest levels of risk that they would tolerate for both potential cancer (range 1/1,000 to 1/2) and potential birth defects (range 1/1,000 to 1/3) to benefit their child with hypothetical hydroxyurea treatment. Parents of 29 of the 58 children were unwilling to take any cancer risk whatsoever as a potential side effect of treatment, and 29 of 58 (not all the same parents) were unwilling to take any risk for birth defects, including half the children with severe SCD. For those families who did accept some risk, higher acceptable risk correlated with higher disease severity in the child (P = 0.04). The study's mixed findings highlight the complexities of risk perception and suggest that future studies of risks and benefits from the parental viewpoint are needed as candidate therapies are developed for SCD.

Der(8)t(1;8) in myeloblastic transformation of ET with hydroxyurea as the sole prior treatment

We described a patient with ET that evolved into MF and then subsequently developed myeloblastic transformation. A novel derivative chromosome der(8)t(1;8) was identified in the AML phase. The only prior treatment had been hydroxyurea. We hypothesized that AML in this case resulted from a complex pre-disposition by the natural progression of ET, prolonged use of HU, and the prior evolution into MF. The leukemogenic risk of HU is critically appraised.

New Therapies for Sickle Cell Disease

New and developing therapeutic agents for the treatment of sickle cell disease include hydroxyurea (an unlicensed experimental drug in most countries), omega-3 fatty acids, and the Gardos channel inhibitor ICA-17043. Anti-cellular adhesion therapy has considerable prospects; however, it has yet to be translated into clinical practice. For specific disease manifestations, pulmonary hypertension responds well to oral arginine, l-carnitine, and exchange blood transfusion therapy alone or in combination with other agents. Primary stroke prevention with transfusion therapy is now considered standard care. Oral iron chelators are administered increasingly instead of the more inconvenient parenteral desferrioxamine. Deferiprone is licensed in Europe and India, and deferasirox (ICL670) holds out important promise because it has not been shown to affect blood cell counts.

Hydroxyurea therapy for sickle cell disease in community-based practices: a survey of Florida and North Carolina hematologists/oncologists

Little is known about patterns of hydroxyurea (HU) use by community-based hematologist/oncologists (H/Os) for the treatment of sickle cell disease (SCD). Determination of these practice patterns pertaining to adult SCD patients was the focus of this study. A self-administered survey was mailed to H/Os in two southeastern states. Replies were received from 70% of eligible physicians. This study focuses on responses from 184 community H/Os and a comparison group of 30 university-based/affiliated H/Os providing ongoing care for at least 3 SCD patients/month. The majority of community H/O respondents saw less than 3 SCD patients/month. HU was prescribed by more than half (55%) of community H/Os in at least 10% of their patients. The most common reasons cited for prescribing HU include frequent painful crises (76%), chronic pain with frequent narcotic use (58%), and acute chest syndrome (43%). Although the majority of community H/Os care for few patients with SCD, the reported indications for HU were consistent with currently accepted recommendations. However, community H/Os reported acute chest syndrome, stroke, and pulmonary hypertension as indications for HU less often than the academic H/O group. Barriers to wider use of HU include physician concerns about carcinogenic potential, doubts about HU effectiveness, perceived patient apprehension about adverse effects, concern about lack of contraceptive use, and patient compliance. Further resources should focus on updating physicians on recently published material supporting the effectiveness of HU in symptomatic SCD as well as providing management guidelines to optimize the use of HU.

Malignancy in patients with sickle cell disease

Malignancy in patients with sickle cell disease (SCD) has been previously reported, but the types of cancer and its incidence remain undefined. With the advent of hydroxyurea therapy, there is concern about increasing the cancer risk for patients with SCD. The International Association of Sickle Cell Nurses and Physician Assistants identified 52 cases of cancer (49 patients) among 16,613 patients with SCD followed at 52 institutions. The median age at malignancy diagnosis was 34 years (range, 14 months-62 years). Twenty-one cases (40%) occurred in pediatric patients, primarily leukemia (n = 7) or Wilms' tumor (n = 5), with 15 children surviving. Most adults had solid tumors, especially carcinomas, and only nine were known to be alive. Three patients received hydroxyurea before the diagnosis of malignancy. These data provide essential baseline information for the accurate interpretation of future reports of malignancy in patients with SCD, especially those receiving hydroxyurea therapy.

Acute leukemia and myelodysplasia in patients with a Philadelphia chromosome negative chronic myeloproliferative disorder treated with hydroxyurea alone or with hydroxyurea after busulphan

Eighty-three patients with various chronic myeloproliferative disorders [polycythemia vera (PV), essential thrombocytosis (ET), idiopathic myelofibrosis (IMF)] were analyzed for the occurrence of acute myeloid leukemia (AML) and myelodysplasia (MDS) during treatment with hydroxyurea (HU) alone or HU following treatment with busulphan (BU). A total of 58 patients (29 PV, 14 ET, 12 IMF, 3 unclassified) had been treated with HU. Thirty-five of these patients had been treated with HU alone whereas 18 patients had received both HU and BU. The follow-up period was 7.8 years. Twenty-five patients had not been treated with HU. In this patient group, 4 patients had been treated with BU. The follow-up period was 10.5 years. In the HU-treated group (n = 58) 7 patients developed AML and 5 patients MDS. Five of the 12 patients had been treated with HU alone, and 4 patients had received both HU and BU. In the non-HU-treated group (n = 25) 1 patient with PV developed acute myeloid leukemia (AML). This patient had only been treated with phlebotomies. It is concluded that treatment with HU is leukemogenic, with an incidence of AML and MDS of approximately 14% when used alone. The incidence is markedly increased to about 30% when HU is preceded by treatment with BU. HU is not recommended for use in younger patients, in whom non-leukemogenic agents such as alpha-interferon and anagrelide should be used instead.

Pathophysiological-based approaches to treatment of sickle cell disease

Sickle hemoglobin (HbS), as a result of its polymer-related and oxidant effects, damages the sickle erythrocyte, provokes inflammation, and causes endothelial injury. All these elements cause the phenotype of sickle cell disease. Novel treatments inhibit HbS polymerization by inducing fetal hemoglobin expression, prevent or repair erythrocyte dehydration by slowing cellular potassium and water loss, and replace HbS-producing erythroid progenitors by stem cell transplantation. Future treatment prospects include gene therapy, interruption of the interaction of sickle cells with the endothelium, inhibition of oxidative damage, and protection of an injured endothelium.

The role of hydroxyurea in the management of sickle cell disease

Sickle cell disease (SCD) is one of the most common genetic diseases with some 250,000 new births each year. Most patients suffer intermittent pain crises and life-threatening events while life expectancy is considerably reduced. Until the last decade management was purely preventative or supportive aimed at symptom control. Apart from stem cell transplant, there is no cure but the oral chemotherapeutic drug hydroxyurea (HU) has now established a role in ameliorating the disease and improving life expectancy for most patients. There are side effects and risks of HU treatment in SCD but for moderate and severely affected patients, the benefits can be significant.

Hydroxyurea treatment of sickle cell anemia in hospital-based practices

In a published randomized clinical trial, hydroxyurea (HU) improved clinical outcomes in patients with sickle cell anemia (SCA). The mean treatment duration of that trial was 21 months. Here we attempt to determine whether the benefits associated with HU therapy of SCA have led also to successful patient acceptance of HU treatment in community practices, and whether successful clinical outcomes persist beyond 2 years. This is an observational retrospective chart study of the computerized medical records of 60 men and women with SCA who had HU treatment for at least 3 months and who were treated at teaching hospital subspecialty clinics in Baltimore, Maryland, and Washington, D.C. Thirty had remained on therapy for at least 24 months. Admissions declined in this group by 30% (P = 0.04). Declines were seen also in transfusion requirements (-58%, P = 0.07). In 17 of these 30 patients, at least 48 months of follow-up records were available. Fourteen of these remained on therapy the entire period, with similar and sustained reductions in admissions and transfusions. We conclude that hydroxyurea therapy of SCA applied in community settings leads to declining admissions and transfusion rates in many individuals for 4 years or more.

Developing treatment for sickle cell disease

Sickle cell disease pathophysiology results from sickle haemoglobin polymerisation and its effects on the sickle erythrocyte and the vasculature. Many of the abnormalities of sickle cell disease are secondary to the damage caused by the polymer and the injured red cell. Pharmacological treatment of the disease is focused on the inhibition of sickle haemoglobin polymerisation, prevention or repair of red cell dehydration and interruption of the interaction of sickle cells with the endothelium.