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Strains Responsible for Invasive Meningococcal Disease in Patients With Terminal Complement Pathway Deficiencies
Jérémie Rosain1,2,3, Eva Hong2, Claire Fieschi4,5
1Laboratory of Immunology, Hôpital européen Georges-Pompidou, Assistance Publique-Hôpitaux de Paris (AP-HP).
Background:
Patients with terminal complement pathway deficiency (TPD) are susceptible to recurrent invasive meningococcal disease (IMD). Neisseria meningitidis (Nm) strains infecting these patients are poorly documented in the literature.
Methods:
We identified patients with TPD and available Nm strains isolated during IMD. We investigated the genetic basis of the different TPDs and the characteristics of the Nm strains.
Results:
We included 56 patients with C5 (n = 8), C6 (n = 20), C7 (n = 18), C8 (n = 9), or C9 (n = 1) deficiency. Genetic study was performed in 47 patients and 30 pathogenic variants were identified in the genes coding for C5 (n = 4), C6 (n = 5), C7 (n = 12), C8 (n = 7), and C9 (n = 2). We characterized 61 Nm strains responsible for IMD in the 56 patients with TPD. The most frequent strains belonged to groups Y (n = 27 [44%]), B (n = 18 [30%]), and W (n = 8 [13%]). Hyperinvasive clonal complexes (CC11, CC32, CC41/44, and CC269) were responsible for 21% of IMD cases. The CC23 predominates and represented 26% of all invasive isolates. Eleven of the 15 clonal complexes identified fit to 12 different clonal complexes belonging to carriage strains.
Conclusions:
Unusual meningococcal strains with low level of virulence similar to carriage strains are most frequently responsible for IMD in patients with TPD.