A young woman with sudden onset of a severe coagulation abnormality

Blood samples were received from a 29-year-old woman who had been admitted to the resuscitation room of an Accident and Emergency department. A full blood count showed: hemoglobin concentration 15.2 g/dl, white cell count 9.6 x 10 9 /l, and platelet count 39 x 10 9 /l. A citrate sample for coagulation tests was unclottable. An urgent blood film confirmed thrombocytopenia and showed heavily vacuolated neutrophils and a left shift. Many of the neutrophils contained organisms (top) and in some cells it was apparent that they were diplococci (bottom left). A Gram stain showed the organism to be Gram-negative (bottom right) and a provisional diagnosis of meningococcal septicaemia with disseminated intravascular coagulation was made. A latex agglutination test for meningococcal antigen confirmed the diagnosis and the organism was typed as Neisseria meningitidis group C. Despite appropriate early and vigorous management, the patient required several amputations and succumbed to the effects of the meningococcal infection 3 weeks after presentation. Peripheral blood neutrophils in meningococcal septicaemia show characteristic features-toxic granulation, degranulation, and marked vacuolation. Organisms are often detectable within the neutrophils and permit an early provisional diagnosis.