The aim of our study was to assess the cytokine profile of sickle cell disease (SCD) patients in steady state and in vaso-occlusive crisis (VOC). VOC has a complex nature, involving interactions between sickle red blood cells (RBC), the endothelium, and leucocytes. Endothelial damage due to recurrent adhesion of sickle RBCs may disrupt endothelial function, leading to altered cytokine release. It is therefore pertinent to study the cytokine profile of SCD patients in steady state and in crisis prior to exploring its contribution to vasoocclusive manifestations, since it is believed that an altered balance of proinflammatory and anti-inflammatory cytokines plays an important role in painful crisis. Cytokines including IL1b, IL-2, IL-4, IL-6, IL-8, TNF-a, and IFN-g were measured by commercially available ELISA kits in SCD patients (n = 60); in steady state (n = 26) and in painful crisis (n = 34) and compared with nonanemic age-and sex-matched normal Omani controls (n = 20). SCD patients in crisis showed elevated levels of TNF-a (P < 0.092) and IL-6 (P < 0.024) when compared with steady state. It was also observed that SCD patients in steady state showed a significant elevation in IL-1b (P < 0.04), IL-6 (P < 0.0001), and IFN-g (P < 0.02) as compared to normal subjects. It is thus evident that both type I and type II cytokines are significantly altered in SCD patients. In steady state, type II proinflammatory cytokines are elevated, whereas in crisis, an additional augmentation of type I cytokines occurs, with persistent elevation of type II cytokines, emphasizing the role of perturbed endothelium and activated monocytes in the pathophysiology of vaso-occlusion in sickle cell crisis. Am.

Individuals with sickle cell disease (SCD) demonstrate an increased susceptibility to invasive bacterial infections (IBI). The most common organisms causing IBI are Streptococcus pneumoniae, nontyphi Salmonella species and Haemophilus influenzae type b (Hib). IBI are the most common causes of death in children below 5 years of age with SCD. Increased susceptibility to IBI is because of several factors including dysfunctional antibody production and opsonophagocytosis as well as defective splenic clearance. Early diagnosis of Hib and pneumococcal infections combined with antibiotic prophylaxis and immunization programs, could lead to significant improvements in mortality, especially in Africa.

Infarction of orbital bones during vaso-occlusive crises in sickle cell disease presents acutely with a rapidly progressive periorbital swelling. Haematomas frequently complicate the condition and, along with the inflammatory swelling, may lead to orbital compression syndrome. The condition is therefore sight-threatening, and necessitates prompt diagnosis and appropriate management for resolution without adverse sequelae. Imaging techniques are invaluable in the evaluation of patients. The majority of cases resolve with conservative treatment that includes steps to combat the vaso-occlusive crisis and use of systemic steroids under antibiotic cover.

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Summary. What appears to be a hitherto unreported type of congenital anaemia has been found in six members of an Irish family. It is inherited in an autosomal dominant manner and is characterized by moderate anaemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphological abnormalities of the red cells (which are, however, well haemoglobinized), erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow, and in the peripheral blood after splenectomy. Potassium flux across the red cell membranes is increased and there is imbalanced globin chain synthesis with α‐chain production exceeding that of β‐chains by a factor of 2/1. Excess α‐chains in the bone marrow form a pool of similar magnitude to that observed in β‐thalassaemia heterozygotcs but the latter do not have red cell precursor inclusion bodies or the degree of ineffective erythropoiesis seen in the present cases. The most likely molecular mechanisms for this disorder are either an ‘overproduction abnormality’ of α‐chain synthesis, or a defect in cell division leading to increased amounts of genetic material per cell, a mechanism postulated recently as a basis for the unusual distribution of red cell enzyme levels in congenital dyserythropoietic anaemia.