[Prospective 2-year clinical study of patients with positive IgG-antibodies after recovering from severe acute respiratory syndrome].

OBJECTIVE

To investigate the clinical characteristics of patients recovering from severe acute respiratory syndrome (SARS) during 2 years after the infection.

METHODS

The antibody of SARS-IgG, T cell subsets, chest CT, and the pulmonary function were observed in patients 1 month, 3 months, 6 months, and 2 years after convalescence from SARS.

RESULTS

In the 20 SARS cases, the level of antibodies was found to descend gradually and slowly during 2 years after convalescence. In the majority of patients T cell subsets recovered completely to normal range at the second examination. At the first re-examination, the rate of abnormal chest CT was 65%, and the main abnormal images included ground glass opacities, thickening of inter-lobular and intra-lobular septa, distorted lobular structure, thickened bronchovascular bundles, thickened pleura, arc shadow under the pleura, bronchiolar dilation, and honey comb like shadows. The rate of abnormal chest CT was 30% at the 4 fourth examination. At the first re-examination, the abnormal rate of KCO was highest, accompanied by abnormalities of forced expiratory volume in 1 second (FEV1) and the diffusing capacity of the lung for carbon monoxide (DLCO), and it began to recover since the third examination.

CONCLUSION

The level of SARS-IgG descends slowly, and it may last for a long time. The recovery of chest CT to normal may take a long time. The abnormality in pulmonary functions manifests mainly as impairment of diffusion function. Further research on SARS is necessary.