Scientific Comments Paula Bolton-Maggs 'University of Manchester and Manchester Blood Center, Plymouth Grove, Manchester, UK Comments on 'Clinical course of 63 children with hereditary spherocytosis: a retrospective study' – with the particular question: 'Should HS be treated the same way throughout the world?' Conflict-of-interest disclosure: The author declares no competing financial interest Submitted: 1/13/2011 Accepted: 1/14/2011 Corresponding author: Paula Bolton-Maggs Haemovigilance scheme (SHOT – Serious Hazards of Transfusion) Manchester Blood Centre Plymouth Grove, Manchester M13 9LL, UK Paula.Bolton-Maggs@manchester.ac.uk www.rbhh.org or www.scielo.br/rbhh DOI: 10.5581/1516-8484.20120002 Rev Bras Hematol Hemoter. 2012;34(1):3-8 The authors describe a retrospective study of 63 children with hereditary spherocytosis (HS) in Minas Gerais, Brazil.(1) HS is generally a mild and benign disease which is found in all areas of the world, but most commonly in peoples of Northern European origin. In this study, as elsewhere, more severe forms of the disorder were diagnosed earlier in life. The classification of Eber et al.(2) has been useful in defining the severity and children at risk of complications and those in whom splenectomy is indicated. The principles of diagnosis and management, as outlined in recent guidelines,(3) can be applied in all locations and populations. It is important to make a correct diagnosis; this is usually straightforward when there is a positive family history and typical physical findings of splenomegaly with spherocytes seen on the blood smear. It is important to review the blood smear carefully and to consider alternative diagnoses if the findings are not typical. Congenital dyserythropoietic anaemia type II can be missed, and if the red cell morphology is not typical, other red cell membrane disorders must be considered. Anaemia may or may not be present (many individuals have compensated haemolysis with a normal haemoglobin) but reticulocytosis is usual. Jaundice is variable. Both anaemia and jaundice are increased under stress, particularly in the face of any type of infection. Aplastic crises are most commonly attributable to parvovirus B19 infection (as in other types of haemolysis). This may precipitate the first presentation of the child and it is important not to assess severity of the HS until the child is fully recovered. It is often not necessary to perform the osmotic fragility (or any other diagnostic) test when other features are typical as this is a laborious and time-consuming test, that can give false negative results.(3) The management of people with HS is supportive; folate supplements are indicated certainly in moderate and severe HS but not necessarily in mild HS if the diet is adequate. Red cell transfusions may be needed in severe cases but children tolerate anaemia well, even with Hb 6-8 g/dL and transfusions should not be based on the Hb level alone as this may lead to unnecessary transfusions with increased risk of iron overload.(3) The level of transfusions at 35 (55% of patients) in this survey(1) is surprisingly high given that only 13 had severe disease. Iron supplementation should not be given unless there is additional evidence of deficiency. People with anaemia of any cause will have increased iron absorption, and those with congenital haemolysis are at risk of iron loading. Generally HS is diagnosed in childhood and it is important to encourage a normal level of activity and lifestyle. Most people with HS have splenomegaly; this is not an indication by itself neither for splenectomy nor for any reduction in activity. Follow-up, particularly in children, is important to check adequate growth and development especially in those with severe and moderate HS; checkups should generally be at 6 to 12 month intervals rather than 3-monthly as suggested by these authors unless there are other medical problems. For children with mild HS, annual follow-ups are adequate and adults with mild and stable HS often need no regular appointments. An important question is when and whether to do splenectomy. It is clear that the spleen removes spherocytic red cells and this is responsible for the decreased red cell survival. Splenectomy results in an increase in red cell survival and in most cases, a normal Hb, and is thus very effective treatment. It is clearly indicated in severe (Hb 6-8 g/dL, reticulocytes > 10%) and some moderate HS (Hb 8-12 g/dL, reticulocytes > 6%),(2) but not in mild HS where the risks usually outweigh the benefits. The main risk is of overwhelming sepsis with encapsulated organisms, typically pneumococcus (the most common culprit), haemophilus influenza and meningococcal species. Splenectomy should be deferred until after 6 years of age if possible because of infection risks. Prior to splenectomy, all individuals should be vaccinated against these organisms. There may be local variations in vaccination practice related to national guidelines and predominant microbiological species. Although post splenectomy penicillin prophylaxis is often 3