Scrub typhus: radiological and clinical findings.

OBJECTIVES: To describe the radiological and clinical findings of scrub typhus. We retrospectively analysed the radiographic, thin-section CT and clinical features of scrub typhus. METHODS: The study included 75 consecutive patients (median age = 47 years, range = 18-81 years) with scrub typhus. Plain chest radiographs were obtained in all 75 patients and 19 underwent thin-section CT within 6 days of initial radiography. The radiographic and thin-section CT findings were retrospectively analysed by three radiologists. RESULTS: Most common clinical symptoms were fever (73/75, 98%), myalgia (61/75, 81%) and headache (60/75%, 80%). Rash (59/75, 79%) and eschar (56/75, 75%) were the most common signs. Radiography showed abnormalities in 54/75 (72%) patients. The most frequent findings were parenchymal abnormalities (53/75, 71%) with lower lung predilection including bilateral reticulonodular opacities (30/75, 40%), ground-glass opacity (19/75, 25%), consolidation (19/75, 25%), septal lines (27/75, 36%) and hilar lymph node enlargement (19/75, 25%). Thin-section CT (n = 19) showed ground-glass opacity (17/19, 89%) predominantly in the lower zones. Bronchial wall thickening (11/19, 58%), centrilobular nodules (9/19, 47%) and interlobular septal thickening (9/19, 47%) were less frequent findings. CONCLUSIONS: Scrub typhus is an acute febrile illness characterized by eschar, which usually has a limited course without serious complication. Diffuse bilateral reticulonodular opacities with lower lung predominance was the most frequent radiographic finding. Chest radiography and thin-section CT show pulmonary interstitial disease which may have a component of pulmonary oedema secondary to cardiac dysfunction.

Association of complement alleles C4AQ0 and C4B5 with rheumatoid arthritis in Koreans.

OBJECTIVE: To investigate the association of complement C4 allotypes with rheumatoid arthritis in Koreans. METHODS: 65 rheumatoid arthritis patients and 255 controls were typed for C4 allotypes and HLA-A, B, C, DR, and DQ antigens. RESULTS: The frequencies of C4AQ0 (32.3% v 14.9%, P < 0.005) and C4B5 (29.2% v 12.2%, P < 0.005) were significantly increased in rheumatoid arthritis patients compared with healthy control subjects. Among rheumatoid patients, the frequency of C4AQ0 was significantly increased in both the rheumatoid factor (RF) positive (27.3%) and the RF negative (66.7%) subgroups. The frequencies of C4B5 and HLA-DR4 were significantly increased only in RF positive subgroup. C4B5 was strongly associated with HLA-DR4, whereas C4AQ0 did not show association with DR4. CONCLUSIONS: In Koreans, C4AQ0 and C4B5 are associated with susceptibility to rheumatoid arthritis, as in the Japanese. C4B5 is strongly associated with HLA-DR4. C4AQ0 is considered to be a DR4 independent risk factor, and a disease susceptibility allele in linkage disequilibrium with C4AQ0 is suggested in Korean patients with rheumatoid arthritis.