Is it necessary to add the eluate testing to the direct antiglobulin test to improve the detection of maternal erythrocyte alloantibodies?

BACKGROUND: The screening of umbilical cord blood samples by the Direct Antiglobulin Test (DAT) is the reference tool for the identification of maternal erythrocyte alloantibodies present in erythrocytes; however, its diagnostic usefulness is controversial. OBJECTIVE: To evaluate the diagnostic validity, safety, and efficiency of the eluate testing (detection of antibody in erythrocyte eluates by the Indirect Antiglobulin Test/IAT) in cord blood samples for detection of maternal erythrocyte alloantibodies in comparison with the DAT. MATERIALS AND METHODS: Evaluation study of diagnostic tests. DAT and eluate testing were performed in 306 cord blood samples from neonates born to mothers admitted at Clínica Somer in Rionegro, Colombia; then, antibodies present in the eluates were identified with erythrocyte panels. Percentage of positive results by DAT and IAT were compared with the Pearson's chi-square test and the agreement between both assays with the Cohen's kappa coefficient. The diagnostic sensitivity, specificity, safety, and efficiency of the eluate testing were calculated, taking into account the use of DAT as an imperfect reference test. RESULTS: The DAT detected alloantibodies in 6.21% of samples and the eluate testing in 14.1 %; the strength of agreement between both tests was moderate (k = 0.56) due to 25 discrepancies. The eluate testing showed sensitivity and specificity of 98.83 % and 92.31 % respectively, and a negative predictive value of 99.9 %. The diagnostic efficiency was sufficient for detection of maternal erythrocyte alloantibodies. The antibodies identified in the erythrocyte eluates were anti-A or anti-B (79.5 %), anti-D (136%), anti-C (2,3%), and anti-Fya (2,3%). CONCLUSION: The eluate testing in cord blood samples is a valid, safe, and efficient test for the diagnosis of maternal erythrocyte alloantibodies.

Anterior open bite and its relationship with dental arch dimensions and tongue position during swallowing and phonation in individuals aged 8-16 years: A retrospective case-control study.

OBJECTIVE: To determine the relationship between AOB and factors such as dental arch dimensions and tongue position during swallowing and phonation. MATERIAL AND METHODS: A case-control study was performed in two groups: 132 children with Anterior Open Bite (AOB) and 132 with normal vertical overbite (NVO), aged 8-16 years selected from the records taken by a previous study from five public schools. Dental arch dimensions were assessed through digitalized study models. Swallowing was evaluated using the Payne technique, and phoniatric assessment included an adaptation of the articulation test used to describe phonemes. STATISTICAL ANALYSIS: Chi-Square or Fisher's exact test for comparisons between qualitative variables and the Mann Whitney or T-student were applied to compare the dental arch dimensions according to bite type. A logistic regression model was applied to control the effect of confusion between independent variables and to describe its simultaneous effect on the type of bite. RESULTS: Intercanine, interpremolar and intermolar widths showed higher values in AOB patients with a mean deviation (MD) of 0.536 (P=0.031), 0.60 (P=0.043) and 1.15, (P<0.001) respectively. Distortions caused by tongue interposition and thrust, tongue protrusion during swallowing, mandibular arch intermolar width, total maxillary arch length, maxillary arch perimeter, and posterior arch depth accounted for 64.6% of AOB and allowed for correct predictions in 83.8% of the cases observed in the study population. CONCLUSIONS: A significant association between tongue position and function, as well as alterations such as tongue interposition and thrust during swallowing and phonation in individuals with AOB, were observed. There is a relationship between AOB and the presence of a wider mandibular arch and a narrower, longer, and deeper maxillary arch.