Respiratory infections are the most frequent presenting infections, and respiratory physicians the most common source of referral. Conclusions: There is still considerable delay in the diagnosis of primary antibody deficiency, but the data suggest an improvement in NM107 practice since the previous study in 1989 and the distribution of national guidelines in 1995. test). The most common presenting symptom was respiratory tract infection (78 of 89), with pneumonia requiring hospital treatment occurring in 33 of 89 and bronchiectasis (diagnosed on computerised tomography scan) in 18 of 89 patients. of primary antibody deficiency, but the data suggest an improvement in practice since the previous study in 1989 and the distribution of national guidelines in 1995. test). The most common presenting symptom was respiratory tract infection (78 of 89), with pneumonia requiring hospital treatment occurring in 33 of 89 and bronchiectasis (diagnosed on computerised tomography scan) in 18 of 89 patients. Otitis occurred in 16 patients, sinusitis in 17, gastroenteritis in six, meningitis in two, osteomyelitis in one, and septic arthritis in one. The most common sources of referral to our clinic were respiratory physicians (36%), general physicians (19%), haematologists (13%), paediatricians (10%), and general practitioners (6%), with specialists in infectious diseases, gastroenterology, rheumatology, neurology, and ear, nose, and throat surgery accounting for 16% of referrals. DISCUSSION Despite the widespread availability of immunological diagnostic methods, these data support the hypothesis that there remains a considerable delay in the diagnosis of primary antibody deficiency. We found a delay in 56 of the 87 (64%) patients in our present study, compared with 71% in our previous study.8 If patients with XLA are excluded, then diagnostic delay was found in 66% of adults compared with 93% previously. Take home messages Our results suggest that there is still a considerable delay in the diagnosis of primary antibody deficiency, resulting in substantial morbidity (equivalent to two major infections and one minor infection) However, there has been an improvement in practice since our previous study in 1989 and also since the distribution of national guidelines in 1995 The median delay in diagnosis of two years and median morbidity score of 25 points compares favourably with our previously reported delay of 5.5 years in adults and BSG morbidity score of 40 points. Overall, the data suggest an improvement in practice over the past 14 years. The data for the period 1989C1995 and 1996C2002 suggest a further more recent improvement, possibly related to the distribution of UK national guidance in NM107 1995. Nevertheless, the median morbidity score of 25 points, equivalent to two major infections requiring hospital admissions plus one minor infection, highlights the clinical consequences of suboptimal diagnosis. For one patient, the morbidity score reached 250 points before diagnosis was reached. Common variable immune deficiency: respiratory manifestations, pulmonary function and high-resolution CT scan findings. Q J Med 2002;95:655C62. [PubMed] [Google Scholar] 7. Chapel HM. Consensus on the diagnosis and management of primary antibody deficiencies. BMJ 1994;308:581C5. [PMC NM107 free article] [PubMed] [Google Scholar] 8. Blore J, Haeney MR. Primary antibody deficiency and diagnostic delay. BMJ 1989;298:516C17. [PMC free article] [PubMed] [Google Scholar] 9. Kainulainen L, Nikoskelainen J, Ruuskanen O. Diagnostic findings in 95 Finnish patients with common variable immunodeficiency. J Clin Immunol 2001;21:145C9. [PubMed] [Google Scholar] 10. Spickett GP, Askew T, NM107 Chapel HM. Management of primary antibody deficiency by consultant immunologists in the United Kingdom: a paradigm for other rare diseases. Qual Health Care 1995;4:263C8. [PMC free article] [PubMed] [Google Scholar] 11. Conley ME, Notarangelo LD, Etzioni A. Diagnostic criteria for primary immunodeficiencies. Clin Immunol 1999;93:190C7. [PubMed] [Google Scholar].