Roles of histologic examination and polymerase chain reaction in diagnosis of toxoplasmic lymphadenitis / 中华病理学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the roles of histologic examination and polymerase chain reaction in diagnosis of toxoplasmic lymphadenitis (TL).</p><p><b>METHODS</b>Forty-six archival cases of histologically diagnosed TL, encountered during the period from April, 1999 to September, 2009 and with the paraffin-embedded lymph node tissue blocks available, were enrolled into the study. The presence of genome fragments of Toxoplasma gondii (T. gondii) was analyzed using semi-nested polymerase chain reaction (PCR). Thirty cases of one or two histopathologic triad of TL as the controls.</p><p><b>RESULTS</b>The positive rate of PCR in TL group was 76.1% (35/46), as compared to 10.0% (3/30) in the control group. The difference was of statistical significance. The sensitivity and specificity of the histologic triad in diagnosing TL was 92.1% (35/38) and 71.1% (27/38), respectively. The predictive value of positive and negative PCR results was 76.1% (35/46) and 90.0% (27/30). respectively.</p><p><b>CONCLUSIONS</b>The high specificity but low sensitivity of applying the histologic triad in diagnosing TL cases may be due to the occurrence of atypical histologic pattern. The sensitivity is improved with the use of semi-nested PCR in detecting T. gondii DNA.</p>