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Marco Lai

Publications and source records attributed to Marco Lai.

5 recordsLinked to original sources
PubMed2006

Lower hemoglobin levels in human immunodeficiency virus-infected patients with a positive direct antiglobulin test (DAT): relationship with DAT strength and clinical stages.

BACKGROUND: There are conflicting opinions regarding the effect of positive direct antiglobulin test (DAT) on hemoglobin (Hb) levels in human immunodeficiency virus-infected (HIV+) patients. STUDY DESIGN AND METHODS: A total of 166 samples from HIV+ outpatients were studied. The DAT was performed with the tube test and column agglutination technology (CAT). RESULTS: The DAT was positive in 18.67 percent with the tube method and 33.73 percent with the CAT. Patients with DAT-positive results showed lower Hb levels than DAT-negative patients, 12.3 g per dL versus 14.3 g per dL (p = 0.0002). The univariate logistic regression enabled us to study the phenomenon better and fit the probability of having a DAT-positive result on the basis of the Hb levels. The relationship between the CAT and the tube test when washing the red blood cells (RBC) at 4 degrees C was stronger than when washing these at room temperature (phi = 0.8156; p = 0.000). The Hb levels were significantly lower in the positive DATs of Stage C (acquired immune deficiency syndrome [AIDS]) and Stage B (symptomatic non-AIDS patients), which showed decreasing Hb values for increasing agglutination strengths (p = 0.000). Anemia was related with the DAT results (odds ratio [OR], 8.005; p = 0.000) but not to the AIDS condition (OR, 1.741; p = 0.221). DISCUSSION: Our study indicates that the DAT-positive results may be specifically related to lower Hb levels in HIV+ patients. The immunologic RBC clearance could be part of the anemic multifactorial condition in HIV+ patients.

Anemia↗
PubMed2006

Non-invasive detection of fetal rhesus D status: a comparison between polymerase chain reaction and flow cytometry.

OBJECTIVE: A non-invasive prenatal determination of the fetal RhD status might be useful for the management of pregnancies in RhD-negative women whose partners are RhD positive. METHODS: Maternal peripheral blood of 32 RhD-negative women (17-24 weeks of gestation) was collected, and circulating fetal cells were enriched by CD71 mini-magnetic activated cell sorting. The RhD status of the fetuses was assessed using multiparametric flow cytometry, and results were compared to those of reverse transcriptase (RT)-polymerase chain reaction (PCR), or PCR, which acted as control. Flow-cytometric study of fetal cells employed monoclonal antibodies directed against CD71, glycophorin A (GPA) and RhD antigens. RESULTS: The median percentage of CD71- and RhD-positive cells was 0.83% (range 0.14-6.44%), and that of CD71 and GPA-positive cells was 10.07% (range 0.52-45.84%). Flow-cytometric analysis correlated with RT-PCR results of RNA obtained from whole maternal blood. In 1 case, an incorrect result was due to the failure of the amplification of the specific RhD band on RNA extracted from the CD71-positive fraction. In two instances, we observed false-positive results for RhD in PCR of DNA obtained from maternal plasma. CONCLUSION: Based on our results, flow-cytometric analysis might be proposed as a clinical tool for the non-invasive prenatal determination of the fetal RhD status independently of fetal gender.

Antibodies, Monoclonal↗
PubMed2005

Detection of weak D with a fully automated solid-phase red cell adherence system.

BACKGROUND: Microplate agglutination methods (MAMs) and column agglutination technology are widely employed for red cell typing and can be automated. Some tests, however, such as detection of weak D, require manual testing. The possibility of detecting weak D by a solid-phase RBC adherence (SPRCA) test was studied in a fully automated system. STUDY DESIGN AND METHODS: The results of 2609 blood samples, characterized as being D- or with a incomplete agglutination reaction, were analyzed for the presence of the weak D phenotype. The 2609 samples were tested by a weak D tube test (antiglobulin method) and a weak D-test with the new SPRCA method. When weak D was detected, which D epitope was involved and whether it was associated with a partial D phenotype were determined. RESULTS: Weak D was detected in 60 (2.3%) of the 2609 samples. The 60 samples that were weak D by the tube test were also weak D+ with the new automated SPRCA test. The sensitivity and specificity for the new weak D typing method were 100 percent, when compared with the standard weak D manual test. CONCLUSIONS: These results support the possibility of performing weak D detection with a SPRCA fully automated system. These preliminary results are encouraging, showing good sensitivity and specificity of the test. Detection of weak D will permit full automation of blood typing.

Blood Banking↗
PubMed2003

CD34-positive cells in human umbilical cord blood express nerve growth factor and its specific receptor TrkA.

In this study, we investigated whether hematopoietic stem cells (HSC) and progenitors present in human cord blood can express nerve growth factor (NGF)-specific receptors, TrkA and p75. Our results showed a marked expression of TrkA and NGF in cord blood CD34(+) cells. A gradient of TrkA and NGF expression exists and is highest in cord blood CD34(+) cells, reduced in cord blood mononuclear cells (MNC) and minimal in mononuclear cells isolated from adult peripheral blood. Our findings suggest that NGF may play a role in the differentiation of hematopoietic progenitors and indicate a different requirement for NGF by immune cells, depending on their state of maturity.

Adult↗