Prevention and treatment of infection in patients with an absent or hypofunctional spleen: A British Society for Haematology guideline

Guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen were published by the British Committee for Standards in Haematology in 1996 and updated in 2002 and 2011. With advances in vaccinations and changes in patterns of infection, the guidelines required updating. Key aspects included in this guideline are the identification of patients at risk of infection, patient education and information and immunisation schedules. This guideline does not address the non-infective complications of splenectomy or functional hyposplenism (FH). This replaces previous guidelines and significantly revises the recommendations related to immunisation. Patients at risk include those who have undergone surgical removal of the spleen, including partial splenectomy and splenic embolisation, and those with medical conditions that predispose to FH. Immunisations should include those against Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus) and influenza. Haemophilus influenzae type b (Hib) is part of the infant immunisation schedule and is no longer required for older hyposplenic patients. Treatment of suspected or proven infections should be based on local protocols and consider relevant anti-microbial resistance patterns. The education of patients and their medical practitioners is essential, particularly in relation to the risk of serious infection and its prevention. Further research is required to establish the effectiveness of vaccinations in hyposplenic patients; infective episodes should be regularly audited. There is no single group ideally placed to conduct audits into complications arising from hyposplenism, highlighting a need for a national registry, as has proved very successful in Australia or alternatively, the establishment of appropriate multidisciplinary networks.

Pneumococcal vaccine coverage in Japan among patients with a history of splenectomy: Results of a retrospective administrative database study

BACKGROUND

Splenectomy results in immune deficiency and increases the risk of clinically significant infections, termed overwhelming post-splenectomy infection (OPSI). In Japan, vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPSV23) is covered by the Japanese National Health Insurance (NHI) for post-splenectomy patients, but there are limited data about whether these patients receive PPSV23 vaccination.

METHODS

We performed retrospective analyses of the JMDC Claims Database comprising employees (including some retired individuals) and their families in Japan. We identified patients who underwent splenectomy (registration period: January 1, 2005-June 30, 2019) at ≥ 2 to ≤ 64 years old, and obtained information about PPSV23 vaccination, reasons for splenectomy, and prevalence/complications of pneumococcal infectious diseases (including OPSI-related disorders).

RESULTS

Among 7,394,182 registered individuals, splenectomy was performed in 475, with an incidence rate of 1.6 cases per 100,000 person-years. Of 414 patients who underwent splenectomy at ≥ 2 to ≤ 64 years of age, their mean ± standard deviation age was 45.4 ± 15.7 years and 63.3% were 45-64 years old. Splenectomy was incidental in 55.3%. Overall, 123/414 patients were prescribed PPSV23 vaccination, resulting in vaccination coverage of 29.7%. The median interval from splenectomy to vaccination was 1.0 month (range: -1 to 85 months).

CONCLUSION

This was the first study to document PPSV23 vaccination coverage after splenectomy in a Japanese real-world setting. PPSV23 coverage is quite low in Japan relative to that in other countries.