EVALUATION OF PROTEIN C IN NIGERIAN PATIENTS WITH SICKLE CELL ANAEMIA IN STEADY STATE

Abstract

BACKGROUND
Sickle cell disease is a genetic disorder of haemoglobin with a world-wide
distribution. Nigeria, the most populous African country has the highest cohort
of sickle cell anaemia patients. Hence the need for more research studies on
sickle cell disease in this part of the world.
The clinical manifestation of sickle cell disease vary enormously ranging from
asymptomatic to patients disabled by recurrent pain and chronic complications,
the most devastating probably being occurrence of stroke in a patient with
sickle cell disease.
Sickle cell disease is considered a prethrombotic state; certain characteristics of
sickle cell such as abnormal adhesivity and absence of membrane phospholipid
asymmetry are involved in the thrombotic process. Most of the morbidity of
sickle cell disease is related to the appearance of occlusion of the
microvasculature resulting in widespread ischaemia and irreversible organ
damage.
Protein C is a Vitamin K dependent serine protease and naturally occuring
anticoagulant that plays a role in the regulation of haemostasis by inactivating
Factors Va and VIIIa in the coagulation cascades. Activated Protein C is a
down regulator of blood coagulation resulting in protection against thrombosis.
It also has anti-inflammatory effects through its inhibition of cytokine
generation and also exerts profibrinolytic properties that facilitate clot lysis.
OBJECTIVE
To evaluate Protein C in Nigerian patients with sickle cell anaemia in steady
state so as to assess their prothrombotic tendency compared with normal
individuals.
Sub-objectives
Evaluation of Prothrombin time (PT), Activated partial thromboplastin time
(APTT) and liver function tests (LFT) in sickle cell anaemia patients in steady
state.
METHOD
The study was carried out at the University College Hospital Ibadan. The study
population comprised of forty sickle cell anaemia patients who are in steady
state, asymptomatic for at least two weeks and forty healthy normal HbA
control subjects, age and sex matched who satisfy the inclusion criteria as
contained in the methodology. Protein C was assayed with Amax Destiny plus
Coagulometer using clot based method.
RESULTS
There was a significant decrease in the Protein C in sickle cell anaemia patients
in steady state (median value 62.8%) compared with HbA controls (median
value 74.6%) (P=0.000).
The HbS patients had significantly higher APTT (median value 48.5s) than the
control subjects (median value 44s). (P=0.025).
However, no significant difference was found between liver function tests of
the HbS patients and the control subjects. (ALT: P=0.823, Albumin: P=0.117,
Total Protein: P=0.371).
Spearman rank correlation coefficient (rho) between protein C and other
parameters of the patients are as follows; PT (rho=0.30, p=0.06). APTT
(rho=0.21, p=0.19). ALT (rho=0.1, p=0.54) Albumin (rho=0.23, p=0.16) Total
protein (rho 0.02, p=0.92)
None of the parameters had significant relationship with protein C in HbS
patients in steady state. (p>0.05 in all cases.)
CONCLUSION
The low Protein C level observed in HbS patients in steady state may not be due
to hepatic dysfunction as LFT in the subjects were found to be normal.
Further studies should focus on comparing Protein C in steady state and in crisis
in Nigerian sickle cell disease patients

EVALUATION OF PROTEIN C IN NIGERIAN PATIENTS WITH SICKLE CELL ANAEMIA IN STEADY STATE