Meningococcal Infection and Complement Inhibitors
Complement inhibitors inhibit the formation of terminal complement, which has a dramatic effect in preventing the symptoms and complications observed in PNH. Terminal complement is not required for combating most infective organisms but is needed to prevent Neisserial infection.
Patients Treated with Complement Inhibitors
Patients treated with complement inhibitors are therefore predisposed to developing infections from the Neisseria group of bacteria, resulting in meningococcal sepsis or meningitis from the bacterium Neisseria meningitides.
In order to reduce the risk of patients on complement inhibitors developing meningococcal sepsis, all patients starting complement inhibitors are vaccinated with 2 vaccines, to be repeated every 5 years.
- A quadrivalent vaccine against the meningococcal strains A, C, W and Y.
- A vaccine against serotype B, the commonest serotype observed in the UK.
At the end of 2019, it was agreed by the PNH National Service with advice from the UK Meningitis Reference Center to add ‘Rescue’ antibiotics.
- All patients’ complement inhibitor will keep 2 doses of a second antibiotic of Ciprofloxacin 500 mg as a backup.
- This should be taken if feeling unwell, e.g. having a raised temperature (above 38c), and if there is a delay in receiving medical care/advice.
This should not replace contacting a healthcare professional for advice and assessment.
Patients are also strongly advised to take daily prophylactic antibiotics, either penicillin V 500 mg twice daily (or erythromycin 500 mg twice daily if allergic to penicillin). The service will assess your response to the above vaccines and revaccinate as required.
The Safety Card
All patients on complement inhibitors are given a patient safety card to carry with them, which both advises them what to do if they become unwell and serves to alert health care professionals that they are at an increased risk of developing meningococcal infection.
Patients are given emergency out-of-hours contact numbers for their PNH Centre. If a patient on complement inhibitor becomes unwell, we advise calling for support. They should also have emergency numbers for their local haematology department.
If a patient with PNH is unwell and develops a temperature, it is important that they are reviewed immediately by a healthcare professional. If meningococcal infection is suspected, they should be commenced on either a third-generation cephalosporin (if not neutropenic) or meropenem (if neutropenic). The PNH team who sees the patient should also be contacted urgently.
Patients on Pegcetacoplan/Iptacopan
In addition to the above, patients on Pegcetacoplan/Iptacopan require vaccination for Haemophilus influenza and pneumococcus – both of which can cause chest infections.