Complement deficiency represents 5% of primary immunodeficiencies worldwide. A total of seven patients with deficiencies of the classical complement pathway were reported in the Czech Republic by the end of 2015. Typical manifestations of complement deficiency are recurrent meningitis, other bacterial infections, autoimmunity and kidney disease.Two case reports are presented of patients with molecularly confirmed C7 (compound heterozygote, c.663_644del in exon 6 and c.2350+2T:>C in intron 16) and C8 (homozygous c.1282C>T in exon 9) deficiency. The first patient had four attacks of meningococcal meningitis and an episode of pneumonia of unknown aetiology in childhood. The second had six attacks of meningitis. He also suffered from recurrent infections (otitis media, tonsillitis, chronic mucopurulent rhinitis and subsequent pansinusitis complicated by nasal polyposis) since childhood. No autoimmune disease was documented in either patient. They both received meningococcal and pneumococcal vaccines. Antibiotic prophylaxis was used only in the second patient, leading to a decline in the number of ENT infections.Complement deficiency should be suspected in patients with recurrent meningococcal infections, especially if combined with other infections caused by encapsulated bacteria or autoimmunity diseases. Prophylaxis with conjugate polysaccharide vaccines is recommended and antibiotic prophylaxis should be considered in individual cases.
Keywords: complement systém - immunodeficiency - meningitis - invasive meningococcal disease - vaccination..