Autoantibodies in falciparum malaria: a sequential study in 183 Thai patients.

Various autoantibodies were sequentially studied in 183 consecutive Thai adults infected with Plasmodium falciparum. On the first day of admission, 31.1% of the patients had positive fluorescent anti-nuclear antibodies (FANA) and 16.9% had positive smooth muscle antibodies (SMA). The incidences of positive FANA and SMA rose progressively with times when the patients returned for the 2 and 4 week follow-ups after discharge, although most of their malaria was cured. The majority of the positive FANA and SMA titres lay between 1:20 and 1:160. The positivity of the FANA and SMA did not correlate with the complications of malaria, nor the initial serum IgG or IgA levels. However, they significantly correlated with the initial hyper-IgM. More interestingly, almost all of the positive FANA were of the speckled type of nuclear staining. The antigen specificity of the speckled FANA were found not to be the double stranded DNA or the extractable nuclear antigens. The polyclonal B cell activation in active malarial infection was postulated.