Northern region asplenia register--analysis of first two years

Abstract

Objectives-To assess the feasibility of setting up a register of patients with asplenia within a defined geographical area; to ensure that guidelines on best practice were implemented; to obtain information on antibody levels to pneumococcal capsular polysaccharides and Haemophilus influenzae type b capsular polysaccharide, before and after immunisation and annually thereafter; to raise awareness of risks among clinicians and to oVer advice on management. Design-Prospective recruitment using multiple sources of recruitment. Annual follow up reminders sent from Registration Centre. Subjects-Population of (old, pre-1995) Northern Health Region: approximately 3.1 million. Main outcome measures-Data were obtained on reasons for asplenia, duration of asplenia, use of prophylactic antibiotics, Medic-Alert bracelets, immunisations, antibody levels, death. Results-The register was initiated at the beginning of April 1995 and ran to the end of March 1997. After two years of operation, 1111 cases had been registered but the response from some health districts was poor. Major primary causes of asplenia were trauma (264), other surgical (198), lymphoproliferative disease (154), and idiopathic thrombocytopenic purpura (147). There were 664 patients on prophylactic antibiotics, of whom 498 were on continuous antibiotics. Only 18 had any type of warning bracelet. Antibody measurements were carried out at least once on 75% of patients; 306 patients had satisfactory antibody levels on first blood sample in year 1, rising to 405 in year 2; 43 patients failed to make any antibody response to Pneumovax despite multiple immunisations, and three patients failed to respond to Hib vaccine. Sixteen patients with satisfactory antibody levels in year 1 had low levels in year 2 requiring vaccine boosters. Sixteen deaths were reported, two of which were directly attributable to overwhelming sepsis. Conclusions-Registration has been successful and has raised awareness of the management of asplenia. Compliance with antibiotic prophylaxis and immunisation was initially poor. A potential high risk group of vaccine non-responders has been identified and poor persistence of pneumococcal antibodies has been identified which is likely to alter approaches to immunisation in asplenic patients. (J Clin Pathol 1999;52:424-429)

Adherence to preventive measures after splenectomy in the hospital setting and in the community

“…However, the need for immunization against H. influenzae type b and N. meningitidis is not well taken into account by hospital physicians, with respectively 44% and 24% of vaccine coverage at hospital discharge. The insufficient coverage for meningococcal and Haemophilus vaccinations was found in all recent studies, with similar results in a 2001 study in Canada [19,20,21].…”

Pneumococcal Conjugate Vaccines Overcome Splenic Dependency of Antibody Response to Pneumococcal Polysaccharides

“…Patients with anatomical or functional asplenia are particularly at risk (13,32) because the spleen is the most important site of phagocytosis of poorly opsonized antigens in the early phase of bacterial invasion, before sufficient amounts of specific antibodies have been produced (26). After a splenectomy, the liver will partially take over the phagocytic function of the spleen.…”

Pneumococcal antibody levels after pneumovax in patients with rheumatoid arthritis on methotrexate

“…We measured pneumococcal antibody levels in each patient and compared these in those who had been vaccinated with those who had not, using Student's unpaired t test. Absolute antibody levels under 35 units were considered to indicate unprotected status, based on levels affording protection in splenectomised patients 13. We compared variables between vaccinated and unvaccinated groups, and those with and without previous pneumonia, using Fisher's exact test.…”