BACKGROUND: Acute rheumatic fever (ARF) affects millions of children in the third world countries like India. The diagnosis of rheumatic fever is based on the Jones criteria with serological titers, antistreptolysin O titer (ASO), and anti-deoxyribonucleic B (ADB), taken as evidence of recent streptococci infection. There is a lack of recent data available on ASO and ADB titers in children from the Delhi/NCR and thus adequate geographical area-specific cutoffs for the region are not available.
AIMS AND OBJECTIVES: The aim of this study is to determine and compare the ASO and ADB antibody titers in children with acute pharyngitis, ARF, rheumatic heart disease (RHD), and in healthy children of the Delhi/NCR region.
MATERIALS AND METHODS: Twenty-six cases of ARF, 51 cases of RHD, 50 cases of acute pharyngitis, and 84 healthy normal children were included in the study. A single ASO and ADB titer measurement was done in these children.
RESULTS: The ASO titers was raised in acute pharyngitis - 303 IU/ml (interquartile range [IQR], 142-520 IU/ml) and ARF - 347.5 IU/ml (IQR, 125-686 IU/ml) children in comparison to healthy controls - 163.5 IU/ml (IQR, 133-246.5 IU/ml) and RHD patients - 163 IU/ml (IQR, 98.250-324.500). The ADB titers were highest in ARF patients - 570.5 IU/ml (IQR, 276-922 IU/ml) followed with RHD - 205 IU/ml (IQR, 113.6-456.5), healthy controls - 78.25 IU/ml (IQR, 53.39-128.15 IU/ml), and acute pharyngitis - 75.12 IU/ml (IQR, 64.5-136 IU/ml). The upper limit of normal (ULN) values of ASO and ADB computed from normal healthy children were 262.4 IU/ml and 134.44 IU/ml, respectively, and these can be used as cutoff values for recent streptococcal infection in this geographical area.
CONCLUSIONS: The median ASO titers in acute pharyngitis group and ARF were significantly raised compared to that of the control group. The ADB titers were raised in ARF and RHD patients albeit the levels were higher in ARF patients. The derived ULN values can be used as cutoff reference.
