Pandolfi F, Alario C, Girardi E, Rava L, Ippolito G, Kunkl A, Aiuti F
Department Clinical Medicine, La Sapienza University, Rome, Italy.
Clin Exp Immunol. 1998 Mar;111(3):564-73. doi: 10.1046/j.1365-2249.1998.00520.x.
We report on the experience of establishing a national network for a quality control programme in evaluating CD4 cell counts in most Italian centres involved in the care of patients with HIV disease. The 68 centres were divided according to their geographical location into eight groups, and twice a year (tests A and B) they received three coded whole blood samples (two were replicates of the same sample) obtained from two informed HIV+ patients, one with CD4 counts/mm3 expected to be < 200 and one with values > 300. The medians of the determinations performed by the labs involved in each of the eight areas were taken as the 'true' values for each sample. Unsatisfactory performances for percentage of CD4 cells were identified as a CD4 analysis with residual values > or = +/- 5% and with deviates > or = +/- 2. For absolute numbers of CD4 cells, an unsatisfactory performance was defined as CD4 counts with residual > +/- 100 CD4 cells/mm3 and with deviates > or = +/- 2. The residual value is the CD4 value reported by each lab minus the median value. The deviate is the residual divided by the modified interquartile range (IQR x 0.75). Most of the centres provided reliable results. However, some labs failed to provide satisfactory results for percentages (6.25% of the tested labs for test A and 6.17% for test B) or absolute numbers (16.25% test A and 12.34% test B). Only 3.7% of the labs gave unsatisfactory results in both tests. Four of the unsatisfactory results from the two tests gave an error in absolute numbers > +/- 200 CD4 cells/mm3. Our data suggest that most Italian labs provide reliable results in evaluating the numbers of CD4 cells in HIV-1+ samples, but the importance of running a quality control programme is highlighted by our experience with those centres which provide unsatisfactory data which may lead to incorrect classification of the patients or assessment of treatment.
我们报告了在意大利大多数参与艾滋病患者护理的中心建立全国性网络以开展CD4细胞计数质量控制项目的经验。68个中心根据地理位置分为8组，每年两次（测试A和测试B），它们收到从两名知情的HIV阳性患者身上获取的三份编码全血样本（其中两份是同一样本的复制品），一名患者的CD4细胞计数/立方毫米预期低于200，另一名患者的计数高于300。参与八个区域中每个区域检测的实验室所做测定的中位数被视为每个样本的“真实”值。CD4细胞百分比的表现不佳被定义为CD4分析的残差值大于或等于±5%且偏差大于或等于±2。对于CD4细胞的绝对数量，表现不佳被定义为CD4计数的残差大于±100个CD4细胞/立方毫米且偏差大于或等于±2。残差值是每个实验室报告的CD4值减去中位数。偏差是残差除以修正后的四分位间距（IQR×0.75）。大多数中心提供了可靠的结果。然而，一些实验室在百分比（测试A中6.25%的受测实验室，测试B中6.17%的受测实验室）或绝对数量（测试A中16.25%，测试B中12.34%）方面未能提供令人满意的结果。只有3.7%的实验室在两项测试中都给出了不满意的结果。两项测试中四个不满意的结果在绝对数量上产生了大于±200个CD4细胞/立方毫米的误差。我们的数据表明，大多数意大利实验室在评估HIV - 1阳性样本中的CD4细胞数量时提供了可靠的结果，但我们在那些提供不满意数据的中心的经验凸显了开展质量控制项目的重要性，这些数据可能导致对患者的错误分类或治疗评估。
