Neutrophil chemotaxis in sickle cell anaemia, sickle cell beta zero thalassaemia, and after splenectomy.

Neutrophil chemotaxis was evaluated in 28 patients with sickle cell anaemia, 10 patient with sickle cell beta zero thalassaemia, 25 patients who had undergone splenectomy, and 38 controls. The mean distance migrated by patients' neutrophils was not significantly different from that of neutrophils from controls. Although several immunological variables have been reported to be changed after loss of splenic function, we were unable to show a defect in neutrophil chemotaxis that could account for the increased susceptibility to infection.     

Myocardial infarction in sickle cell disease.

Gross and microscopic findings consistent with acute (three patients) and healed (four patients) myocardial infarction were found in seven (9.7%) of 72 consecutive hearts from patients with sickle cell disease studied after autopsy between 1950 and 1982. Gross obstructive and atherosclerotic lesions were absent in all seven patients, while microthrombi were present in the arterioles of infarcted tissue in two patients. Pathophysiological mechanisms responsible for the infarction are unclear, but anemia, platelet thrombi, coronary vasospasm, and abnormal rheology related to sickle cells may all be important. Chest pain occurred clinically in six of the seven patients and ECG findings typical of infarction were found in two patients. One patient died suddenly. These findings suggest that ischemic heart disease may be present in a significant number of patients with sickle cell disease and should be considered in all patients who complain of chest pain, whether or not the patient is in crisis.     

Anaemic crisis in sickle cell disease.

Sixteen episodes of acute anaemia necessitating urgent blood transfusion have been investigated in 13 children with sickle cell anaemia. In five out of seven episodes there was evidence of increased haemolysis while in 10 out of 16 episodes a profound fall in reticulocyte count indicated marrow erythroid cell failure. Cold agglutinins active at room temperature were detected in 13 episodes, and anti-I specificity was demonstrated in 11. Warmed blood of homologous ABO and Rhesus groups was administered without complication despite difficulty with cross-matching. The exacerbation of anaemia was not due to folate lack, glucose-6-phosphate dehydrogenase deficiency or splenic sequestration, and an infectious agent appeared responsible. The degree of anaemia in homozygous sickle cell disease is usually constant during asymptomatic periods. An episode of sudden profound anaemia (anaemic crisis) may, however, result from marrow hypoplasia, an exacerbation of haemolysis, splenic sequestration, or folate deficiency.     

Increased activation of the alternative complement pathway in sickle cell disease

Complement proteins play an important role in host defenses against Streptococcus pneumoniae, a major cause of serious infections in sickle cell (SS) disease. Previous studies have suggested abnormalities of the alternative complement pathway in SS disease. We measured activation of the alternative pathway in sera from patients with SS disease utilizing an enzyme immunoassay which detects C3b,P complexes, derivative of the C3b,Bb,P alternative pathway convertase. In all, 89% of SS sera had elevated concentrations of C3b,P complexes, indicative of increased alternative pathway activation. Chronic activation of the alternative pathway may contribute to impaired host defense in SS patients.     

Sexuality and sickle cell disease.

Chronic illness can impact negatively on sexuality and sexual satisfaction. A group of 44 patients with sickle cell anemia and a control group of 42 individuals with no chronic illness completed the Derogatis Sexual Functioning Inventory (DSFI). The sickle cell anemia group also completed the Psychosocial Adjustment to Illness Scale--Self-Report (PAIS-SR). Cumulative scores on the PAIS-SR were used to divide the sickle cell anemia group into two subgroups--those who were poorly adjusted to their illness and those who were well adjusted to their illness. Analysis of the scores showed significant differences in sexual functioning and sexual satisfaction between those in the sickle cell group who were well adjusted to their illness and those who were poorly adjusted. Of note was the fact that there was no statistically significant difference between the DSFI scores in the well adjusted group and the control group. Other significant factors included the lack of accurate sexual information in the sickle cell anemia group and the importance of satisfaction with the health-care system in total adjustment to illness. In addition, results revealed that severity of illness had little impact on adjustment to illness.     

Serum protein profile in sickle cell disease.

The total protein, albumin, globulin, and immunoglobulin levels of sera from 96 children with homozygous sickle cell disease were studied. A comparison of the results with the levels found in a control group of normal children of the same age shows that the sicklers have higher total protein, globulin, and IgM levels. The amounts of albumin and IgA seen were almost the same in both groups. The IgG levels differed considerably, the sicklers having only about half the quantity seen in normal children.     

Creatine kinase activity in sickle cell disease.

Creatine kinase activity was measured in 28 patients in the steady state of sickle cell disease and ranged from 4-45 IU/l, comparable with that found in healthy adult caucasians. Creatine kinase activity was also measured in 14 patients admitted consecutively for the treatment of vaso-occlusive sickle cell crises. Creatine kinase activity remained within the normal range in eight of these 14 patients throughout their admission; none had muscle pain or a chest syndrome. In the remaining six, three with muscle pain and three with a chest syndrome, increased activity was found on one or more days. A further 17 patients with vaso-occlusive sickle cell crises, associated with muscle pain, were studied. Creatine kinase activity was significantly raised in all 17, the mean creatine kinase activity for men was 578.8 IU/l and 210.6 IU/l for women, with the highest values (up to 1790 IU/l) found in those who had exercised before admission. Measurement of creatine kinase activity may therefore be a useful marker of muscle perturbation due to sickling.     

Complement activation in asymptomatic patients with sickle cell anaemia.

Previous reports have suggested that a defect in serum complement may contribute to the increased susceptibility to infection shown by patients with sickle cell anaemia (SCA). In order to define the nature of any complement abnormality in SCA, we investigated the complement system in eighty-seven patients during asymptomatic periods, and analysed factor B turnover in a small sample. In these patients geometric mean serum concentrations of functionally active factor B and factor D, and of C3 and C4 protein (expressed as a percentage of normal reference serum) wer lower than in controls (78% vs 107%, P less than 0.001, 86% vs 103%, P less than 0.001, 91% vs 100%, P less than 0.01, 89% vs 105%, P less than 0.05 respectively). The ratio of the serum concentration of functionally active factor B to factor B protein was lower in patients than in controls (means 75% s.d. 16% vs mean 93%, s.d. 22% P less than 0.001), indicating a functional deficiency of factor B protein. In addition, the fractional catabolic rate of radiolabelled factor B was markedly increased in four out of seven asymptomatic patients studied, and was inversely related to the functional factor B concentration in serum (r = -0.59, P less than 0.05); factor B synthesis was uniformly increased. Complement activation was not related to the presence of circulating C1q binding material. We conclude that complement activation, rather than defective synthesis as previously suggested, contributes to the abnormalities in complement componenet concentration and function in asymptomatic subjects with sickle cell anaemia.     

HCV in sickle cell disease

The sickle cell gene is common in the U.S. In fact 8% of African Americans are healthy carriers of the sickle cell trait (HbAS). People who are homozygous (HbSS) have severe disease. They have life-long anemia, chronic hemolysis, and also have at times hematological crises, which can worsen the anemia. Many patients require chronic transfusions and as a result, substantial proportions of sickle cell patients are at high risk for infection with blood-borne diseases-such as Hepatitis C Virus infection (HCV). The HCV antibody positivity is directly related to the number of transfusions given, and on average the prevalence rate in transfused patients is more than 10%. It is known that the combination of iron overload and HCV can lead to a more rapidly progressive liver disease. The treatment of HCV in sickle cell patients poses a challenge to clinicians. A novel approach described by some is the pre-treatment of these patients with hydroxyurea to increase the fetal hemoglobin, therefore decreasing the severity of Ribavirin-related hemolysis. Treatment with Peg-interferon alone has not been used to treat HCV in sickle cell patients, but in the setting of controlled clinical trials it would be feasible. This review explores the impact of HCV in sickle cell patients and the possible therapeutic options available to them.     

Depression in sickle cell disease

PURPOSE: To assess the prevalence of depressive symptoms and examine the contribution of demographics, disease severity, and health care use variables to depressive symptoms in sickle cell patients who had been in stable health for at least one month. PATIENTS AND METHODS: Subjects were a convenience sample of 27 men and 23 women selected during a routine visit to the sickle cell clinic at Howard University Hospital. Depression was assessed using a cut-off score from the Beck Depression Inventory (BDI) and related to a variety of health outcomes. RESULTS: The results of the analyses indicate that 44% (n=22) of the sample scored within the mild to severe (>20) range of depression on the BDI. Depressed sickle cell patients were more frequently treated in emergency rooms and more likely to be hospitalized with vaso-occlusive crises. Patients more likely to be depressed were: those with low family income (<$10,000); less than high school education; female; those who had multiple blood transfusions; poor pain control; inadequate social support; hydroxyurea use; and had histories of frequent vaso-occlusive crises. CONCLUSION: The prevalence of depressive symptoms in sickle cell patients is high compared to the general African American population. Our findings confirmed previous studies examining the occurrence of depression in adults with sickle cell disease. Treatment of depression should be strongly considered to improve the quality of life and probably disease course in sickle cell patients.     

Glomerular function and hyperuricaemia in sickle cell disease.

Renal insufficiency is common in adults with homozygous sickle cell disease, and the contribution of glomerular failure to the hyperuricaemia which is often a feature of the disease has therefore been investigated. In a study of 64 patients between the ages of 15 and 66, serum urate concentration was dependent on renal urate clearance and also on creatinine clearance. The relation between serum urate and creatinine clearance was abnormal in patients with sickle cell disease and it is suggested that this might be caused by high single nephron glomerular filtration rates. Both the amount of urate excreted per millilitre of glomerular filtrate and the fractional excretion of urate increased with falling creatinine clearance, suggesting that the ability to increase tubular urate secretion was preserved. Patients with extensive tubular disease as shown by tubular proteinuria had serum urate concentrations which were not significantly different from those of age and sex matched non-proteinuric patients. Evidence that renal tubular disease interferes with urate secretion and causes hyperuricaemia in patients with sickle cell disease needs to be reinterpreted in the light of these findings.