Dynamics of peripheral blood B lymphocytes and natural killer cells in patients with severe acute respiratory syndrome / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the dynamics of peripheral blood B lymphocytes and natural killer (NK) cells in patients with severe acute respiratory syndrome (SARS).</p><p><b>METHODS</b>The absolute numbers of peripheral blood B lymphocytes and NK cells in 602 serial samples from 240 patients with SARS were counted, using flow cytometry, and compared with that of normal population.</p><p><b>RESULTS</b>The absolute numbers of peripheral blood B lymphocytes and NK cells in SARS patients were significantly lower than that of the normal population (P < 0.001) and were much lower in SARS patients with severe or extremely severe types, as compared with that of moderate or mild type cases (P < 0.001). The amount of B lymphocytes in recovery SARS patients increased at the 2nd week after onset, and gradually becoming normal at the 5th week of the disease onset. The number of NK cells was in the low level at onset, and keep decreasing at the 2nd week. However, it was increasing with the recovery of the disease, but did not reach to normal level at the 5th week after onset.</p><p><b>CONCLUSION</b>The absolute numbers of peripheral blood B lymphocytes and NK cells were associated with the severity of the disease, and detection of these two kinds of cells was useful for predicting the prognosis of SARS.</p>

Rapid detection of genotypes of TT virus using a heteroduplex mobility assay / 中华流行病学杂志

<p><b>OBJECTIVE</b>To establish a simple, sensitive, specific and less-costly method for detecting genotypes of TT virus (TTV).</p><p><b>METHODS</b>TTV DNA was tested by nested polymerase chain reaction (nPCR) in sera from 180 patients with different types of viral hepatitis and 96 normal individuals in Beijing. TTV genotypes were determined in 40 sera collected from TTV DNA positive patients by heteroduplex mobility assay (HMA) and through sequencing.</p><p><b>RESULTS</b>The positive rates of TTV DNA in viral hepatitis patients and normal individuals were 22.2% (40/180) and 19.8% (19/96), respectively (chi(2) = 0.220, P = 0.639). TTV DNA positive rates of patients with hepatitis A, B, C, E and non-A to E were 20.0% (6/30), 16.7% (5/30), 23.3% (7/30), 36.7% (11/30) and 18.3% (11/60), respectively. Of 40 TTV DNA positive patients, 20 (50.0%) were TTV G1, 7 (17.5%) TTV G2, 10 (25.0%) coinfected with different genotypes of TTV, and 3 untyped by HMA. Twenty G1 and 7 G2 detected by HMA were confirmed by sequence analysis. Of 10 patients coinfected with different genotypes of TTV, 5 were G1 and G2, 2 G1 and G3, 1 G1 and G4, 1 G1 and G3, and 1 with G1, G2 and G3 coinfections.</p><p><b>CONCLUSION</b>HMA was recognized as simple, sensitive, specific and less-costly, thus could be used for genotyping of TTV.</p>