tailieunhanh - Chapter 060. Enlargement of Lymph Nodes and Spleen (Part 8)

The absence of the spleen has minimal long-term effects on the hematologic profile. In the immediate postsplenectomy period, leukocytosis (up to 25,000/µL) and thrombocytosis (up to 1 x 106/µL) may develop, but within 2–3 weeks, blood cell counts and survival of each cell lineage are usually normal. The chronic manifestations of splenectomy are marked variation in size and shape of erythrocytes (anisocytosis, poikilocytosis) and the presence of Howell-Jolly bodies (nuclear remnants), Heinz bodies (denatured hemoglobin), basophilic stippling, and an occasional nucleated erythrocyte in the peripheral blood. When such erythrocyte abnormalities appear in a patient whose spleen has not been. | Chapter 060. Enlargement of Lymph Nodes and Spleen Part 8 The absence of the spleen has minimal long-term effects on the hematologic profile. In the immediate postsplenectomy period leukocytosis up to 25 000 pL and thrombocytosis up to 1 x 106 pL may develop but within 2-3 weeks blood cell counts and survival of each cell lineage are usually normal. The chronic manifestations of splenectomy are marked variation in size and shape of erythrocytes anisocytosis poikilocytosis and the presence of Howell-Jolly bodies nuclear remnants Heinz bodies denatured hemoglobin basophilic stippling and an occasional nucleated erythrocyte in the peripheral blood. When such erythrocyte abnormalities appear in a patient whose spleen has not been removed one should suspect splenic infiltration by tumor that has interfered with its normal culling and pitting function. The most serious consequence of splenectomy is increased susceptibility to bacterial infections particularly those with capsules such as Streptococcus pneumoniae Haemophilus influenzae and some gram-negative enteric organisms. Patients under age 20 years are particularly susceptible to overwhelming sepsis with S. pneumoniae and the overall actuarial risk of sepsis in patients who have had their spleens removed is about 7 in 10 years. The case-fatality rate for pneumococcal sepsis in splenectomized patients is 50-80 . About 25 of patients without spleens will develop a serious infection at some time in their life. The frequency is highest within the first 3 years after splenectomy. About 15 of the infections are polymicrobial and lung skin and blood are the most common sites. No increased risk of viral infection has been noted in patients who have no spleen. The susceptibility to bacterial infections relates to the inability to remove opsonized bacteria from the bloodstream and a defect in making antibodies to T cell-independent antigens such as the polysaccharide components of bacterial capsules. Pneumococcal vaccine .