title: Haemophilus influenzae type B in an immunocompetent, fully vaccinated ALL survivor.
abstract: A 7-year-old boy with a history of recurrent acute lymphoblastic leukemia (ALL), in remission, presented to primary care clinic after 2 days of progressive right hip pain with weight-bearing activities. He was otherwise asymptomatic at the time of presentation. Blood cultures revealed Gram-negative diplococci, which prompted an MRI that was significant for a hip joint effusion and femoral head bone marrow edema. The patient had no sick contacts and no significant past medical history other than ALL. The patient had been given all recommended childhood vaccinations. Arthrocentesis and needle biopsy of the femoral neck were not diagnostic for malignancy and revealed only mild hip joint inflammation, leading to a diagnosis of osteomyelitis. The organism in the original blood culture was identified as Haemophilus influenzae type b, β-lactamase negative. Review of the patient's medical records showed a history of complete immunization to Haemophilus influenzae type b. An immunologic evaluation was made to determine if the patient retained immunity from his other vaccinations. Pathogen-specific antibody testing revealed detectable antibodies to polio but not measles, mumps, rubella, varicella-zoster virus, tetanus, diphtheria, pertussis, or hepatitis B. This loss of immunologic memory appears to be a rarely described side effect of ALL chemotherapy. There is currently no protocol to evaluate the immunologic memory of patients who underwent chemotherapy for ALL or to revaccinate them after their treatment. It is unclear whether the loss of immunologic memory is genuinely rare or is underdiagnosed because affected patients are protected by herd immunity.
authors.affiliation: Departments of Pediatrics, Naval Medical Center, San Diego, San Diego, California, USA. gtg968h@gmail.com
authors.forename: John
authors.initials: J
authors.lastname: Nevin
authors.forename: Julie
authors.initials: J
authors.lastname: Kanter Washko
authors.forename: John
authors.initials: J
authors.lastname: Arnold
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects; D018771:Arthralgia / Q000503:physiopathology; D001769:Blood / Q000382:microbiology; D002648:Child; D005500:Follow-Up Studies; D006192:Haemophilus Infections / Q000175:diagnosis / Q000276:immunology* / Q000517:prevention & control; D018073:Haemophilus Vaccines / Q000008:administration & dosage / Q000276:immunology*; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods; D007121:Immunocompetence / Q000276:immunology*; D007156:Immunologic Memory / Q000187:drug effects / Q000276:immunology*; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology*; D011859:Radiography; D018570:Risk Assessment; D017741:Survivors; D014611:Vaccination / Q000379:methods
chemical_list: D018073:Haemophilus Vaccines
keywords: Haemophilus influenzae type b; cancer; chemotherapy; infectious disease; leukemia; vaccine