Immunoscintigraphy (BW 250/183) in neonates and infants with fever of unknown origin

Fever of unknown origin is defined as a temperature above 39.0 degrees C to gether with a white blood cell count greater than or equal to 15,000 mm(-3) , the duration of fever exceeding 2 weeks and a correct diagnosis not being obtained in the first week of hospitalization. In neonates and infants wit h fever of unknown origin, the localization of the infectious focus is ofte n difficult and unsatisfactory. In this retrospective study, the clinical v alue of Tc-99(m)-labelled antigranulocyte antibodies for this group of pati ents was investigated. Thirty-two immunoscintigrams were performed using 18 5-259 MBq Tc-99(m)-labelled antigranulocyte antibodies (BW 250/183) in 30 n eonates and infants (21 boys, 9 girls, mean age 29.4 +/- 2 months), who had fever of unknown origin. Immunoscintigraphy was carried out as whole-body images (n = 7) or single planar images (n = 25) 4 h and 24 h post-injection . In children with known cardiac failure, single photon emission tomography of the thorax was performed to diagnose endocarditis (n = 2). For verifica tion, the results of the immunoscintigrams were compared with radiology (co nventional radiography = 14, MRI = 5, CT = 3), biopsy (n = 2), blood cultur e (n = 10) and clinical follow-up after specific therapy. In 11 of 30 child ren (36%), the diagnosis of an infective focus was possible with immunoscin tigraphy. The sensitivity and specificity of diagnosing infective foci was 72% and 95% respectively (n = 11; colitis = 2, infection of the central per manent catheter tip = 2, middle ear infection = 1, spondylitis/discitis = 3 , osteomyelitis = 2, umbilical infection = 1). In vertebral body infections , all lesions were photopenic. In 18 children (60%), no infective focus was found on immunoscintigraphy. In this group of children, the main reason (n = 5) for fever of unknown origin was chronic juvenile rheumatoid arthritis . No uptake was seen in two infants with cardiac failure and suspected endo carditis on SPET In 3 of the 18 patients (17%), localization of an infectiv e focus was not possible with immunoscintigraphy or on other examinations. In these patients, the fever disappeared spontaneously after a few days of antibiotic therapy. In conclusion, we have shown that Tc-99(m)-anti-NCA-95 scanning is a safe method with a high sensitivity and specificity for detec ting infectious foci in neonates and infants with fever of unknown origin. Furthermore, this method is easy to perform, since no withdrawal of blood i s necessary. ((C) 1998 Lippincott Williams & Wilkins).