Value of PCR in the detection of B-thalassemia gene mutations among silents heterozygous carriers: a mulit-stage study

The detection of heterozygous [beta-thalassemia carriers is very important, as they transmit the [3 beta- thalassemia gene to their offspring, for genetic counseling and prenatal diagnosis. The screening of carriers is routinely performed by measuring red blood cells [RBCs] indices and the level of hemoglobin A[2] [HbA[2]]. However, in a considerable number of cases results are equivocal. So this multi-stage study was planned to detect different gene mutations among [Beta-thalassemia trait individuals, with equivocal hematological results age [silent carriers] by PCR. One hundred parents of 50 thalassemic children, besides 20 control age- and sex-matched individuals served as the subjects of this study. Serum iron, hemoglobin [Hb], RBCs indices [HCT, MCV, MCH and MCHC], reticulocytic counts, and one point osmotic fragility [OPOF] test were performed to all subjects. Meanwhile, qualitative detection of [beta -thalassemia mutations, using allele specific oligonucleotides [ASO] was performed to 25 carriers with normal serum iron, RC, OPOF. and/or normal HbA[2] [silent carriers]. The mutations at IVS 1-110, IVS 1-6, IVS I- 1] represented the most common mutations, accounting for 36%,20%, and 12%, respectively. Meanwhile, 3/25 [12%] of mutations were uncharacterized. The sensitivity of OPOF test, HbA[2] by chromatography and PCR in the detection of [beta-thalassemia trait accounted for 86%, 83% and 88%, respectively.Its concluded that for silent carriers, with normal serum iron, RC, RBCs indices, OPOF test and/or normal HbA[2] PCR should be performed

new screening technique for the diagnosis of tuberculous pleural effusion in children

A definitive diagnosis of tuberculosis [TB] requires the recovery of Mycobacterium tuberculosis [MTB] from a patient's secretions, body fluids or tissues. However, the detection rate of MTB, by various methods [Z-N smear, culture and/or PCR], is not high in TB pleural effusions. Several studies, on adult patients, demonstrated that an activity of adenosine deaminase [ADA] level in pleural effusion above 40 lU/L is strongly associated with TB. The objective of this trial was to test the validity of ADA level in the diagnosis of TB pleural effusion, in children. Forty five patients with confirmed TB pleural effusion were studied versus 25 control children with non-tuberculous effusion.The mean age of onset of TB pleural effusion was 9.54 +/- 3.6 years. Males are affected more than females, with an M/F ratio of 3 : 1; 89% of patients had received BCG-vaccination, which finding may indicate doubtful efficacy of the currently used BCG-vaccine against the development of TB pleurisy; Anorexia and weight loss, fever and night sweats, chest wheezes and local signs of pulmonary involvement represent the most common manifestations of TB pleural disease; A low total peripheral blood WBCs counts [with relative lymphocytosis], an increased ESR, a frequently positive tuberculin test are characteristics of TB pleural effusions; Pleural fluid is frequently associated with characteristics of exudate; The average level of ADA activity in pleural fluid of TB children accounted for 116.4 +/- 36 U/L which is statistically higher than that of nontuberculous children, 93% of patients had levels above 60 U/L vz 4% for nontuberculous children; A statistically higher average mean proportion of lymphocytes, in pleural fluid of TB patients, more than nontuberculous ones; The most sensitive tests in the diagnosis of TB pleural effusion in children were ADA [93.3%], lymphocyte proportion [> 50%] in pleural fluid [91.1%], and positive tuberculin skin testing [75.6%]. We conclude that the analysis of ADA levels in pleural effusions constitutes a useful marker for the diagnosis of tuberculous pleural effusion, which in addition, can be made quickly and cheaply