Sickle Red Blood Cells Research Articles

A Dataset of Microscopic Images of Sickle and Normal Red Blood Cells

A Dataset of Microscopic Images of Sickle and Normal Red Blood Cells

RE: Hydroxyurea reduces the levels of the fetal globin gene repressors ZBTB7A/LRF and BCL11A in erythroid cells in vitro

Teaser Text Hydroxyurea is beneficial to patients with sickle cell disease because it increases fetal hemoglobin (HbF), which reduces red blood cell sickling. The mechanism by which hydroxyurea increases fetal hemoglobin is not well established. Martyn et al. show that hydroxyurea treatment of in vitro-differentiated erythroid precursors results in reduced expression of BCL11A and ZBTB7A/LRF, two transcription factors that are well-established repressors of the gamma-globin gene. Interestingly, hydroxyurea also reduces the amount of GATA1 in the cells, and since GATA1 is a positive regulator of the BCL11A and ZBTB7A/LRF genes, this suggests that GATA1 may mediate the effects of hydroxyurea. The work provides hints about the mechanism of action of hydroxyurea, but also leaves open questions about its complex role in increasing fetal hemoglobin.

Minimally invasive treatment with radiofrequency ablation and kyphoplasty for avascular necrosis of the spine in sickle cell disease: illustrative case.

Avascular necrosis (AVN) of the spine is a rare sequela of chronic sickle cell disease (SCD) in which the shape of the sickled red blood cells interfere with the normal vascular supply of vertebral bodies. In this report, the authors describe a case of progressive spinal AVN treated with radiofrequency ablation (RFA) and kyphoplasty for the patient's persistent lower back pain. A 38-year-old male with long-standing spinal AVN due to SCD had been managed conservatively with hydroxyurea and oral opioid analgesics for several years until breakthrough episodes of low-back pain began to occur with an inability to perform activities of daily life. The patient's condition progressed to involve multiple vertebral bodies, leading to a refractory response. Bipedicular RFA directed at L3 and L4 with kyphoplasty was proposed as a novel, minimally invasive approach. The patient was found to have lasting postoperative relief. Patients with pain attributed to a sickle cell crisis can benefit from RFA and kyphoplasty to potentially eliminate or minimize symptoms from spinal AVN due to chronic SCD not responding to conservative management. https://thejns.org/doi/10.3171/CASE24343.

Accompanying Hemoglobin Polymerization in Red Blood Cells in Patients with Sickle Cell Disease Using Fluorescence Lifetime Imaging.

In recent studies, it has been shown that fluorescence lifetime imaging (FLIM) may reveal intracellular structural details in unstained cytological preparations that are not revealed by standard staining procedures. The aim of our investigation was to examine whether FLIM images could reveal areas suggestive of polymerization in red blood cells (RBCs) of sickle cell disease (SCD) patients. We examined label-free blood films using auto-fluorescence FLIM images of 45 SCD patients and compared the results with those of 27 control persons without hematological disease. All control RBCs revealed homogeneous cytoplasm without any foci. Rounded non-sickled RBCs in SCD showed between zero and three small intensively fluorescent dots with higher lifetime values. In sickled RBCs, we found additionally larger irregularly shaped intensively fluorescent areas with increased FLIM values. These areas were interpreted as equivalent to polymerized hemoglobin. The rounded, non-sickled RBCs of SCD patients with homogeneous cytoplasm were not different from those of the erythrocytes of control patients in light microscopy. Yet, variables from the local binary pattern-transformed matrix of the FLIM values per pixel showed significant differences between non-sickled RBCs and those of control cells. In a linear discriminant analysis, using local binary pattern-transformed texture features (mean and entropy) of the erythrocyte cytoplasm of normal appearing cells, the final model could distinguish between SCD patients and control persons with an accuracy of 84.7% of the patients. When the classification was based on the examination of a single rounded erythrocyte, an accuracy of 68.5% was achieved. Employing the Linear Discriminant Analysis classifier method for machine learning, the accuracy was 68.1%. We believe that our study shows that FLIM is able to disclose the topography of the intracellular polymerization process of hemoglobin in sickle cell disease and that the images are compatible with the theory of the two-step nucleation. Furthermore, we think that the presented technique may be an interesting tool for the investigation of therapeutic inhibition of polymerization.

Splenic filtration of red blood cells in physiology, malaria and sickle cell disease.

The human spleen clears the blood from circulating microorganisms and red blood cells (RBCs) displaying alterations. This review analyzes how generic mechanisms by which the spleen senses RBC, such pitting, trapping and erythrophagocytosis, impact the pathogenesis of two major spleen-related diseases, malaria and sickle cell disease (SCD). Scintigraphy, functional histology, comparison of circulating and splenic RBC, ex-vivo perfusion of human spleens and in-silico modeling enable relevant exploration of how the spleen retains and processes RBC in health and disease. Iterative cross-validations between medical observations, in-vitro experiments and in-silico modeling point to mechanical sensing of RBC as a central event in both conditions. Spleen congestion is a common pathogenic process explaining anemia and splenomegaly, the latter carrying a risk of severe complications such as acute splenic sequestration crisis and hypersplenism in SCD. Sickling of hemoglobin S-containing RBC may contribute to these complications without necessarily being the trigger. Ongoing progress in the exploration and understanding of spleen-related complications in malaria and SCD open the way to optimized prognosis evaluation and therapeutic applications.

FT-4202, a selective pyruvate kinase R activator for sickle cell disease

Anemia in patients with sickle cell disease (SCD) increases 2,3-diphosphoglycerate (2,3-DPG), decreasing hemoglobin–oxygen (Hb-O2) affinity to improve oxygen offloading and promote hemoglobin polymerization (sickling) of red blood cells (RBCs). We report the discovery of FT-4202, an investigational, selective pyruvate kinase type-R (PKR) activator with a multimodal mechanism of action and potential to increase ATP and decrease 2,3-DPG, resulting in increased Hb-O2 affinity, decreased Hb polymerization, and improved RBC health. FT-4202 was identified via structure-enabled lead optimization medicinal chemistry using X-ray crystallography, molecular modeling, and thermal shift assays. FT-4202, an allosteric PKR activator, stabilizes the tetrameric enzyme and increases PKR activity in human and mouse RBCs in vitro. Seven-day oral administration of FT-4202 in Berkeley SCD mice reduced 2,3-DPG, increased Hb-O2 affinity, and reduced RBC sickling versus control. There were no adverse in vitro safety findings. FT-4202 offers a therapeutic opportunity to modify the course of SCD.

Liver and renal biochemical profiles of people with sickle cell disease in Africa: a systematic review and meta-analysis of case-control studies

BackgroundSickle cell disease (SCD) is a genetic blood disorder characterized by a painful vaso-occlusive crisis due to the sickling of red blood cells in capillaries. Complications often lead to liver and renal dysfunctions, contributing to morbidity and mortality, particularly for children under 5. This systematic review and meta-analysis aimed to evaluate the liver and renal functions of people with SCD (HbSS) compared to those without it (HbAA) in Africa.MethodsThe protocol was registered with PROSPERO (CRD42022346771). We searched PubMed, Embase, Web of Science, and Google Scholar using the keywords “liver function”, “renal function”, “sickle cell disease”, and “Africa” on 6th May 2023 for peer-reviewed articles with abstracts in English. We included case-control studies comparing SCD (HbSS) with controls without hemoglobinopathies (HbAA). We used the random-effect model to calculate the pooled average values for the blood tests of people with SCD in RStudio version 4.2.2.ResultsOverall, 17 articles were analyzed from five African countries involving 1312 people with SCD and 1558 controls. The pooled mean difference of liver enzymes aspartate transaminase (AST) was 8.62 (95% CI − 2.99–20.23, I2 = 97.0%, p < 0.01), alanine transaminase (ALT) 7.82 (95% CI − 0.16–15.80, I2 = 99%, p < 0.01) and alkaline phosphatase (ALP) − 2.54 (95% CI − 64.72 – 59.64, I2 = 99%, p < 0.01) compared to controls. The pooled mean difference for the renal biochemical profiles creatinine − 3.15 (95% CI − 15.02; 8.72, I2=99%, p < 0.01) with a funnel plot asymmetry of t = 1.09, df = 9, p = 0.3048 and sample estimates bias of 6.0409. The pooled mean difference for serum urea was − 0.57 (95% CI − 3.49; 2.36, I2 = 99%, p < 0.01), and the estimated glomerular filtration (eGFR) rate was 19.79 (95% CI 10.89–28.68 mL/min/1.73 m2, I2 = 87%, p < 0.01) compared to controls.ConclusionPeople with SCD have slightly elevated liver enzymes and estimated glomerular filtration rates compared to controls in Africa. With all the heterogeneity (I2) > 50%, there was substantial variation in the reported articles’ results.Systematic review registrationPROSPERO CRD42022346771

Assessment of serum protein profile in sickle cell disease

Background: Sickle Cell disease (SCD) is known to be caused by a mutation in the beta-globin gene of the hemoglobin that affects the red blood cells (RBCs) and is passed down through generations. This study was carried out to determine the effect of sickling of RBC on serum protein profile in SCD individuals. Methods: A case-controlled study was carried out among 80 patients. They were forty-five sickle cell disease individuals (HbSS) attending Children Specialist Hospital Ilorin and thirty-five healthy controls (HbAA). The levels of total protein and albumin were determined spectrophotometrically and serum protein electrophoresis (SPE) was carried out using cellulose acetate electrophoresis. Results: Significant hypoalbuminemia and hypergammaglobulinemia were observed in SCD groups compared with controls. A higher proportion of the SCD group, 11(25%) had hypergammaglobulinemia and 21(49%) had hypoalbuminemia (P&lt;0.05). Plasma protein electrophoresis in SCD patients shows an intense colour at the gamma region which was not seen in control. There was a significant relationship between the patterns of serum protein electrophoresis and the frequency of crisis. Conclusions: Sickle cell disease crisis and other associated underlying conditions may be prevented early through assessment of serum protein profile, especially SPE. Hypergammaglobulinemia and hypoalbuminemia may be associated with frequent episode of crisis.

Nitrosyl hemoglobin formation from nitrite in normal and sickle blood

Sickle cell anemia is caused by a single mutation in the gene encoding the beta subunit of hemoglobin. Due to this mutation, sickle cell hemoglobin (HbS) polymerizes under hypoxic conditions, decreasing red blood cell deformability and leading to multiple pathological effects that cause substantial morbidity and mortality. Several pre-clinical and human studies have demonstrated that the anion nitrite has potential therapeutic benefits for patients with sickle cell disease. Nitrite is reduced to nitric oxide (NO) by deoxygenated hemoglobin contributing to vasodilation, decreasing platelet activation, decreasing cellular adhesion to activated endothelium, and decreasing red cell hemolysis; all of which could ameliorate patient morbidities. Previous work on extracellular hemoglobin has shown that solution phase HbS reduces nitrite to NO faster than normal adult hemoglobin (HbA), while polymerized HbS reduces nitrite slower than HbA. In this work, we compared the rate of nitrite reduction to NO measured by the formation of nitrosyl hemoglobin in sickle and normal red blood cells at varying hemoglobin oxygen saturations. We found the overall rate of nitrite reduction between normal and sickle red blood cells was similar and confirmed this result under partially oxygenated conditions, but normal red blood cells reduced nitrite faster than sickle red blood cells under anoxia where HbS polymerization is maximal. These results are consistent with previous work using extracellular hemoglobin where the rate of reduction by solution phase HbS makes up for the slower reduction by polymer phase HbS under partially oxygenated conditions, but the polymer phase kinetics dominates in the complete absence of oxygen.

Hypertonicity and/or acidosis induce marked rheological changes under hypoxic conditions in sickle trait red blood cells.

Deformability and sickling of red blood cells (RBCs) from individuals with sickle cell trait (SCT) was evaluated under harsh biophysical conditions that mimic certain vascular beds invivo. RBC deformability in osmotic-gradient ektacytometry was decreased in HbAS (SCT) compared to HbAA (wild-type) RBCs at supraphysiological osmolalities. RBC deformability was also measured by oxygen-gradient ektacytometry. Whereas RBC sickling was not observed under isotonic and neutral pH conditions, hypertonicity and acidosis alone or in combination induced reversible sickling of SCT RBC. These data suggest that hyperosmolality and/or acidosis enhance hypoxia-induced sickling of SCT RBC.

Could oxygen gradient ektacytometry help to detect sickle cell trait carriers at risk for kidney disorders or exercise-related complications?

The study of Ellsworth etal. (Br J Haematol, 2024) demonstrated the usefulness of oxygen gradient ektacytometry technique to better identify the physiological parameters that could increase the risk of sickling of red blood cells (RBCs) from sickle cell trait (SCT) carriers. Oxygen gradient ektacytometry combined with pH and osmolality modulations could help in identifying SCT carriers at risk for kidney disorders or exercise-related complications. Other factors than the percentages of haemoglobin S are probably involved in the propensity of RBCs from SCT carriers to sickle during deoxygenation. Commentary on: Ellsworth etal. Hypertonicity and/or acidosis induce marked rheological changes under hypoxic conditions in sickle trait red blood cells. Br J Haematol 2024; 205:1565-1569.

Safety and Efficacy of L-Glutamine in Reducing the Frequency of Acute Complications Among Patients with Sickle Cell Disease: A Randomized Controlled Study

Abstract Introduction Patients with sickle cell disease (SCD) suffer from recurrent and unpredictable episodes of acute pain due to vaso-occlusive crisis (VOC) which may require hospitalization and they also develop chronic persistent pain. Since pain usually begins in infancy and continues throughout life, preventing the genesis of pain is comparatively higher than treating the pain once it has been evoked VOC represents the cause of almost 95% of hospitalizations for patients with SCD. L-glutamine is an amino acid needed for the synthesis of the pyridines for nucleotides, including nicotinamide adenine dinucleotide (NAD) and glutathione, in addition to glutamate, and becomes essential during oxidative stress exposure. The NADH: [NAD+ + NADH] (redox) ratio in sickle red blood cells (RBCs) is lower than in normal RBCs which is related to oxidative stress, so L-glutamine availability is important in SCD. Although the FDA-approved it for preventing acute complications in SCD, still has many gaps in our understanding of its therapeutic implications. Aim To evaluate the safety and efficacy of L-glutamine in reducing the number of VOCs in patients with SCD. Methods This is an investigator-initiated single-center phase 4 interventional randomized controlled trial at Ain Shams Pediatric Hematology Unit. Sixty SCD participants, their mean age was 9.2 ± 3.7 years, they were 35 males and 25 females, were randomly assigned in a 1:1 ratio to receive glutamine at a dose of 0.3 gm/kg/dose twice daily orally (up to a maximum of 15 g/dose) for 24 weeks or the standard of care (SOC) without glutamine intake. Results Thirty-seven (62%) had HbSS with 38% had other sickle cell variants. All participants were receiving HU therapy and were on stable dose during the last three months prior to enrollment. Almost half of the patients (48%) were on chelation therapy with deferasirox. Thirty SCD patients were recruited in each group either received glutamine or SOC, both groups were comparable as regards demographic data. All patients in both arms had VOCs in the last year more than two. For the primary endpoint, there was a decreasing trend in the number, severity, and hospitalization of VOC in the glutamine arm and there was a significantly lower cumulative number of VOCs in the glutamine group (38.9%) than SOC (52.8%) (p = 0.008) and lower cumulative number of hospitalizations (p &amp;lt; 0.001). Conclusion Glutamine reduced the number of VOCs and hospitalizations for VOC in our cohort with SCD.

A Comparative Evaluation of the Antisickling, Elemental and Proximate Analysis of the Leaves of Three Khaya species Found in Nigeria

Sickle cell disease (SCD) is traditionally treated in Nigeria by the Traditional Medical Practitioners (TMPs) with medicinal plants and other plant products. One of the herbs commonly used singly or in combination with other plant materials is Khaya, which is widely distributed in Africa, with three species existing in Nigeria. These are Khaya senegalensis A. Juss (KS), Khaya grandifoliola (WELW) CDC (KG) and Khaya ivorensis A. Chev. (KI). In this study we evaluated the anti-sickling activities of the leaf extracts of the three Khaya species leaves with a view to authenticating the ethnomedicinal claims, and assess the proximate as well as the elemental constituents that may contribute to the properties. Dried leaves of the Khaya species were extracted by cold maceration and Soxhlet methods using water, ethanol and petroleum spirit as extractives. Filtered extracts were concentrated in vacuo at 40oC and dried in a lyophilizer. Inhibitory and reversal models were employed to evaluate their anti-sickling effects on Hb SS red blood cells following standard procedures. Proximate and elemental analysis were determined using the simple analytical procedure as described by the Association of Official Analytical Chemistry (AOAC) of 1987, 13th Edition Washington DC P1094 and Dry Ashing method of AOAC 2006 respectfully. Anti-sickling results showed that the Soxhlet ethanol extracts of the Khaya species demonstrated significant (p≤0.05) ability to reverse and inhibit the sickling of red blood cells in-vitro with KI having the highest inhibitory and reversal of 60.04+1.77% and 74.97+2.23% respectively at 4 mg/ml concentration. The proximate analysis revealed the richness of the Khaya leaves in minerals, proteins and carbohydrates. Khaya leaves contained calcium, magnesium, sodium, phosphorus, and other essential elements within the limits of dietary requirement. Khaya species could therefore be recommended for further development into herbal remedy in the management of sickle cell disease.

LC-MS/MS Analysis of crude Flavonoid Compounds from &lt;i&gt;Justicia secunda&lt;/i&gt; from Democratic Republic of the Congo and evaluation of their antisickling Activity

&lt;i&gt;Justicia secunda&lt;/i&gt; Vahl (Acanthaceae) is a tropical herbaceous plant traditionally used by indigenous peoples of the Democratic Republic of the Congo (DRC) to treat symptoms associated with sickle cell disease (SCD), a genetic condition with life-threatening complications. Given the lack of side-effect-free drugs, alternative herbal therapies that can reduce or reverse red blood cell sickling may serve as safe and effective treatments. The primary objective of this study is to conduct a phytochemical screening of crude flavonoids extracted from &lt;i&gt;J. secunda&lt;/i&gt; using LC-ESI/MS/MS. &lt;i&gt;J. secunda&lt;/i&gt; extracts were evaluated for their phytoconstituents and anti-sickling properties. The anti-sickling properties were assessed through reverse sickling estimation, polymerization and oxidation inhibition, and osmotic fragility assays. Fractionation of the methanol extract and chemical profiling were performed by flash chromatography and high-performance thin-layer chromatography analysis respectively. Characterization and identification of the crude flavonoids were done using chromatography and spectroscopy methods. Chemical screening of crude flavonoids revealed the presence of 12 flavonoid O-glycosides based on one flavonol (methoxy-kaempferol) and two flavones (luteolin and apigenin). The crude flavonoid extracts demonstrated maximum reversal of sickled red blood cells (91.9 ± 0.8%), significant inhibition of hemoglobin polymerization (77.8 ± 7.6%) and hemoglobin S auto-oxidation (96.3 ± 0.2), and provided maximum protection of red blood cells against hyperhemolysis. The results validate the traditional use of &lt;i&gt;J. secunda&lt;/i&gt; and identify potential compounds for the development of novel anti-sickling agents.

Black Americans With Sickle Cell Disease (SCD) Demonstrate Accelerated Epigenetic Pace of Aging Compared to Black Americans Without SCD.

Sickle cell disease (SCD) is a chronic medical condition characterized by red blood cell sickling, vaso-occlusion, hemolytic anemia, and subsequently, end-organ damage and reduced survival. Because of this significant pathophysiology and early mortality, we hypothesized that patients with SCD are experiencing accelerated biological aging compared with individuals without SCD. We utilized the DunedinPACE measure to compare the epigenetic pace of aging in 131 Black Americans with SCD to 1391 Black American veterans without SCD. SCD patients displayed a significantly accelerated pace of aging (DunedinPACE mean difference of 0.057 points) compared with the veterans without SCD, whereby SCD patients were aging ≈0.7 months more per year than those without SCD (p = 4.49 × 10-8). This was true, even though the SCD patients were significantly younger according to chronological age than the individuals without SCD, making the epigenetic aging discrepancy even more apparent. This association became stronger when we removed individuals with posttraumatic stress disorder from the non-SCD group (p = 2.18 × 10-9), and stronger still when we restricted the SCD patients to those with hemoglobin SS and Sβ0 thalassemia genotypes (p = 1.61 × 10-10). These data support our hypothesis that individuals with SCD experience accelerated biological aging as measured by global epigenetic variation. The assessment of epigenetic measures of biological aging may prove useful to identify which SCD patients would most benefit from clinical interventions to reduce mortality.

Morphological Factors and Forces Acting in Normal and Sickled Erythrocytes in Sickle Cell Anemia: A Mathematical Model

We carried out a theoretical study that considers the morphological factors and forces acting on a normal and a sickled blood cell. Sickle cell disease is associated with vaso-occlusion which creates blood flow crises as a result of loss in shape memory of the normal red blood cell. Certain forces and chemical compositions acting on the cell could retain the shape memory. The problem of a second order partial differential equation modeled was solved to get the forces and chemical composition required to restore the sickled red blood cells back to its original shape. The results gotten showed that, increase in chemical reaction increased the RBC growth by creating a stretching force that causes the sickle cell to regain elasticity with improved oxygen.

Oxygen release from hemoglobin has limited effects on mitochondrial respiration measured from red blood cells. Reply to the Comment on "Increased retention of functional mitochondria in mature sickle red blood cells is associated with increased sickling tendency, hemolysis and oxidative stress".

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Exercise and training in sickle cell disease: Safety, potential benefits, and recommendations.

Sickle cell disease (SCD) is a genetic disorder characterized by complex pathophysiological mechanisms leading to vaso-occlusive crisis, chronic pain, chronic hemolytic anemia, and vascular complications, which require considerations for exercise and physical activity. This review aims to elucidate the safety, potential benefits, and recommendations regarding exercise and training in individuals with SCD. SCD patients are characterized by decreased exercise capacity and tolerance. Acute intense exercise may be accompanied by biological changes (acidosis, increased oxidative stress, and dehydration) that could increase the risk of red blood cell sickling and acute clinical complications. However, recent findings suggest that controlled exercise training is safe and well tolerated by SCD patients and could confer benefits in disease management. Regular endurance exercises of submaximal intensity or exercise interventions incorporating resistance training have been shown to improve cardiorespiratory and muscle function in SCD, which may improve quality of life. Recommendations for exercise prescription in SCD should be based on accurate clinical and functional evaluations, taking into account disease phenotype and cardiorespiratory status at rest and in response to exercise. Exercise programs should include gradual progression, incorporating adequate warm-up, cool-down, and hydration strategies. Exercise training represents promising therapeutic strategy in the management of SCD. It is now time to move through the investigation of long-term biological, physiological, and clinical effects of regular physical activity in SCD patients.

Does hemoglobin affect measures of mitochondrial respiration in red blood cells? Comment to "Increased retention of functional mitochondria in mature sickle red blood cells is associated with increased sickling tendency, hemolysis and oxidative stress".

Does hemoglobin affect measures of mitochondrial respiration in red blood cells? Comment to "Increased retention of functional mitochondria in mature sickle red blood cells is associated with increased sickling tendency, hemolysis and oxidative stress".

Influence of Hemoglobin Variants on Vaso-Occlusive Phenomena in Sickle Cell Anemia: A Review

Sickle cell anemia (SCA) is a genetic disorder characterized by the presence of abnormal hemoglobin S (HbS), leading to the sickling of red blood cells (RBCs) and subsequent vaso-occlusive crises (VOCs). These crises are responsible for acute pain episodes and potential organ damage, significantly affecting the quality of life for individuals with SCA. The clinical presentation of SCA can be modified by various hemoglobin variants, including hemoglobin C (HbC) and hemoglobin E (HbE), which influence the severity and frequency of VOCs through alterations in red blood cell morphology, oxygen affinity, and inflammatory responses. The presence of hemoglobin variants can affect red blood cell rigidity and aggregation, leading to enhanced vascular occlusion and increased susceptibility to VOCs. Hemoglobin C, for instance, results in more rigid RBCs that readily adhere to the endothelium, while hemoglobin E may reduce the degree of sickling due to its higher oxygen affinity. Furthermore, these variants can modulate the inflammatory response, influencing the recruitment of leukocytes and the activation of endothelial cells, thereby contributing to the overall pathophysiology of VOCs in SCA. Individualized treatment approaches, such as hydroxyurea therapy and emerging gene therapies, can be tailored based on the specific hemoglobin variant present in the patient. Continued research is crucial to elucidate the complex interactions between hemoglobin variants and VOCs, ultimately leading to improved patient outcomes and enhanced quality of life for those affected by sickle cell anemia. Keywords: Sickle cell anemia, hemoglobin variants, vaso-occlusive crises, hemoglobin S, hemoglobin C, hemoglobin E, vascular occlusion, inflammation, red blood cells, therapeutic strategies