Creatine kinase activity in sickle cell disease

How Sickle Cell Disease Impairs Skeletal Muscle Function: Implications in Daily Life

Sickle cell disease (SCD) is the most frequent life-threatening genetic hemoglobinopathy in the world and occurs due to the synthesis of abnormal hemoglobin S (HbS). hemoglobin S-containing red blood cells (RBC) are fragile, leading to hemolysis and anemia, and adhere to the endothelium, leading to hemorheological and hemodynamical disturbances. In its deoxygenated form, HbS may polymerize, leading to sickling of red blood cells and potentially to vasoocclusive crises. Recent findings observed that SCD patients demonstrate significant skeletal muscle remodeling and display reduced muscle functional capacities, contributing to exercise intolerance and poor quality of life. Although acute high-intensity exercise is not recommended for SCD patients because it may increase the risk of sickling, regular moderate-intensity physical activity could have beneficial effects on skeletal muscle and more generally on the well-being of SCD patients. This article reviews the literature regarding the impact of the disease on muscular tissue characteristics and function, as well as the corresponding implications for SCD patients' quality of life.

Evaluation of creatine kinase activity and inorganic phosphate concentration in adult nigerian homozygous and heterozygous hemoglobin phenotypes

Background:

Biochemical parameters vary in subjects with different hemoglobin phenotypes, compared with normal controls.

Aim:

The aim was to evaluate serum creatine kinase (CK) activity and inorganic phosphate concentrations in Nigerian adults with homozygous and heterozygous hemoglobin phenotypes.

Subjects and Methods:

A prospective study, carried out at the hematology out-patient clinic of our hospital, a community health center and a private hospital, all in Anambra state. Subjects included hemoglobin phenotypes AA, AS, and SS, in steady state and vaso-occlusive crisis (VOC). Samples were collected for serum CK activity and inorganic phosphate concentrations. Data obtained were analyzed using SPSS 16.0 (SPSS Inc., Chicago IL, USA). Means were compared using the Student's t-test and statistical significance was set at P < 0.05.

Results:

A total of 100 subjects participated in the study. There was a statistically significant difference in the means of serum CK activity in hemoglobin SS (HbSS) in VOC versus hemoglobin AA (HbAA) (P = 0.01) and HbSS in steady state versus HbAA (P = 0.02) but not in hemoglobin AS (HbAS) versus HbAA (P = 0.79) and HbSS in VOC versus HbSS in steady state (P = 0.06). A statistically significant difference was noted in the means of serum inorganic phosphate concentration in HbSS in VOC versus HbAA (P = 0.01), but not in HbSS in steady state versus HbAA (P = 0.43), HbSS in VOC versus HbSS in steady state (P = 0.09) and HbAS versus HbAA (P = 0.20).

Conclusion:

Sickle cell disease is a predictor for high serum CK activity and low serum concentration of inorganic phosphate, particularly in VOC. There may be a need to monitor serum CK activity in HbSS subjects presenting with major VOC.

Apolipoprotein A-I and serum amyloid A plasma levels are biomarkers of acute painful episodes in patients with sickle cell disease

BACKGROUND

Acute painful episodes are the clinical hallmark of sickle cell disease and have been linked to morbidity and mortality in the sickle cell population.

DESIGN AND METHODS

We undertook exploratory proteomic studies on paired plasma samples collected from a cohort of 26 adult sickle cell patients during steady state and on the first day of an acute painful episode. We screened for changes in abundance of specific protein peaks via surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF MS), and confirmed the identify of candidate protein peaks by specific immunoassays.

RESULTS

The levels of hemoglobin, hematocrit, total protein, and albumin were lower and the levels of lactate dehydrogenase and absolute reticulocytes higher during acute painful episodes than during the steady state. Surface-enhanced laser desorption/ionization time of flight mass spectrometry spectral analysis consistently showed a mass-to-charge peak at 11.7 kDa with elevated intensities during acute painful episodes, which correlated significantly with the serum amyloid A immunoassay. Serum amyloid A levels were significantly elevated during acute painful episodes, especially in four patients with marked end-organ complications of such episodes. A second, recurring peak, less abundant during acute painful episodes, was present at 28.1 kDa; this peak was correlated significantly with immunoassay measurements of apolipoprotein A1.

CONCLUSIONS

On the average, plasma serum amyloid A rises and apolipoprotein AI falls during acute painful episodes. The serum amyloid A/apolipoprotein AI ratio increased in 81% of the patients during acute painful episodes, potentially making it a useful objective marker of such episodes. We propose that these protein alterations, known to contribute to endothelial dysfunction in other settings, might do likewise acutely in acute painful episodes and present a new target for therapeutic intervention in sickle cell disease. (ClincalTrials.gov Identifier: NCT00081523).

Variation in serum electrolytes and enzyme concentrations in patients with sickle cell disease

AIM

To assess levels of some biochemical variables in sickle cell disease patients from eastern Saudi Arabia during steady state and in crises states, with a view to comparing biochemical and clinical manifestations of the disease with those in other geographical locations.

METHODS

Serum calcium, uric acid, total bilirubin, lactate dehydrogenase, hydroxybutyrate dehydrogenase, and haemoglobin were measured in 110 sickle cell patients when in steady state. The same variables were measured on 30 of the patients when they went into crisis.

RESULTS

Serum calcium tended to be lower in sickle cell patients than in healthy controls, while uric acid tended to be in the high normal range. Crises did not make any difference to serum calcium but they increased the uric acid level significantly. All the other variables measured were significantly abnormal and more so during crises.

CONCLUSIONS

Although the abnormal levels obtained for these biochemical variables in patients with sickle cell disease from eastern Saudi Arabia were similar to those from other geographical locations, there were noticeable differences in the severity of the abnormalities, which probably explains the differences in the clinical manifestations of the disease between geographical locations. Values of some of these variables could be adapted for use to monitor crises.

Monitoring the acute phase response to vaso-occlusive crisis in sickle cell disease

AIMS

To identify suitable acute phase proteins as objective markers of tissue ischaemia during painful vaso-occlusive crises in sickle cell disease.

METHODS

The prodromal and established phases of 14 vaso-occlusive crises were studied longitudinally in 10 patients with sickle cell anaemia. Automated solid phase enzyme immunoassays were used to measure the fast responding acute phase proteins C-reactive protein and serum amyloid A protein. Slower responding glycoproteins (fibrinogen, orosomucoid, sialic acid and concanavalin-A binding) were measured in parallel.

RESULTS

C-reactive protein and serum amyloid A protein increased early in crisis, sometimes within the early (prodromal) phase. Crises that resolved within 24 hours in hospital showed a minor and transient rise compared with crises that required treatment for four days or more. In eight crises treated by patients at home the acute phase response ranged from minor to a level consistent with extensive tissue ischaemia.

CONCLUSIONS

Sensitive enzyme immunoassays for C-reactive protein and serum amyloid A protein are of potential value for monitoring the onset of tissue ischaemia in sickle cell crisis and for confirming subsequent resolution.

Sickle myonecrosis revisited

This review focuses on the classification of sickle myonecrosis in the context of sickle cell vaso-occlusive crisis. Further, the potential and novel use of magnetic resonance imaging to further clarify the nature of sickle crisis is discussed.