If only they knew! A non-inferiority randomized controlled trial comparing deceptive and open-label placebo in healthy individuals

BACKGROUND

Placebo use is widespread in clinical practice. However, they are most often administered deceptively rather than openly. It is often suggested that open-label placebos (OLP) are less effective than deceptive placebos (DP). This study aimed to compare the use of DP and OLP treatments to reduce pain in healthy volunteers.

METHODS

We conducted a non-inferiority, parallel, randomized, controlled trial, which also included a nested cross-over no-treatment condition. This study was conducted at a university clinic in France.

RESULTS

We included 60 subjects and the main result shows that the OLP was not inferior to the DP by a margin of 10 mm. The mean difference between both groups regarding intensity of pain was 0.7 mm with a 95% compatibility interval (95% CI) of ]-∞; 5.4], and 97.5% CI of ]-∞; 6.3]. Secondary outcomes require cautious interpretation of the effect of placebo versus no treatment due to a time-treatment interaction.

CONCLUSION

The study indicates that OLP may perform just as well as DP and could provide support for the use of OLP as an ethical alternative to DP when they are to be used in a clinical setting. If only patients knew about the placebo nature of some treatments they are receiving, unnecessary lies could be avoided while maintaining similar placebo effects.

SIGNIFICANCE

This study is the first to show non-inferiority of placebos administered honestly, also called OLP, compared to DP in reducing pain. This suggests that OLP could be as effective as their deceptive counterparts while having the ethical advantage of not being required to lie. If deception is not a necessary condition for efficacy, OLP should be preferred over DP.

Neonatal Silver-Russell syndrome with maternal uniparental heterodisomy, trisomy 7 mosaicism, and dysplasia of the cerebellum

OBJECTIVES

We report here the unusual association of Silver-Russell syndrome (SRS) and cerebellar dysplasia with trisomy 7 mosaicism and maternal uniparental disomy of chromosome 7 [UPD(7)m].

METHODS

Low-level trisomy 7 mosaicism was diagnosed prenatally on amniocytes, and UPD(7)m was confirmed after birth.

RESULTS

Medical examination at birth showed dysmorphic facial features of SRS. Cytogenetic analysis on several tissues and cells confirmed mosaic trisomy 7. Unusual severe psychomotor retardation, hypotonia, and choreoathetoid movement were noted at 6 months. Brain magnetic resonance imaging showed both cerebellar hypoplasia and dysplasia.

CONCLUSIONS

This unusual association of SRS and dysplasia of the cerebellum might be related to the presence of the trisomy 7 mosaicism on the cerebellum. Our observation strengthens the hypothesis that the phenotype observed in patients with SRS with UPD(7)m might also result from an undetected low level of trisomy 7 mosaicism that could best be revealed by performing cytogenetic investigations.

Genotype-phenotype correlation in 13q13.3-q21.3 deletion

Pure interstitial deletions of the long arm of chromosome 13 are correlated with variable phenotypes according to the size and the location of the deleted region. Deletions involving the 13q13q21 region are rare. In order to establish interstitial 13q genotype-phenotype correlation, we used high resolution 244K oligonucleotide array in addition to conventional karyotype and molecular (fluorescent in situ hybridization, microsatellite markers analysis) techniques in two independent probands carrying a deletion 13q13 to 13q21. First patient was a 3-year-old girl with mental retardation and dysmorphy carrying a 13q13.3q21.31 de novo deletion diagnosed post-natally. The second one was a fetus with de novo del(13)(q14q21.2) associated with first trimester increased nuchal translucency. We showed that specific dysmorphic features (macrocephaly, high forehead, hypertelorism, large nose, large and malformed ears and retrognathia) were correlated to the common 13q14q21 chromosomal segment. Physical examination revealed overgrowth with global measurement up to the 95th percentile in both probands. This is the second description of overgrowth in patients carrying a 13q deletion. Haploinsufficiency of common candidates genes such as CKAP2, SUGT1, LECT1, DCLK1 and SMAD9, involved in cell division and bone development, is a possible mechanism that could explain overgrowth in both patients. This study underlines also that cytogenetic analysis could be performed in patients with overgrowth.

Prenatal forehead edema in 4p- deletion: the ‘Greek warrior helmet’ profile revisited

OBJECTIVES

Deletion of short arm of chromosome 4 is difficult to ascertain prenatally, and can be missed.

METHODS

A prenatal suspicion of 4p- syndrome was thoroughly investigated by using two-dimensional and three-dimensional sonography, with a description of the fetal face dysmorphological pattern. The cytogenetic confirmation, obtained by karyotype and FISH technique, allowed a precise description of the prenatal abnormalities. Post-termination tridimensional helicoidal scanner of the fetal face was performed.

RESULTS

The main anomaly discovered using two-dimensional sonography was the presence of a strikingly thick prefrontal edema (8 mm, twice the normal values, at 22 weeks: 3.81 +/- 0.62 mm). Three-dimensional sonography showed the classical postnatal profile, with the phenotypic aspect of a 'Greek warrior helmet'. Nasal bones were normal in size and placement, confirmed by helicoidal scanner.

CONCLUSION

Prenatal diagnosis of 4p deletion syndrome can be difficult, and it is the presence of prefrontal edema, associated with more subtle facial anomalies (short philtrum, microretrognathia) which should trigger cytogenetic investigation for 4p- deletion, even with only borderline growth retardation.

Prenatal diagnosis of a (X;X) translocation by fluorescence in situ hybridization and laser scanning image cytometry

A de novo structural abnormality of one X chromosome was prenatally detected in a female fetus. This chromosomal abnormality has been analyzed by conventional cytogenetic methods, fluorescence in situ hybridization, and laser scanning image cytometry. The association of these techniques has demonstrated that this anomaly corresponds to a (X;X) translocation. Analysis of hybridization signals by laser scanning image cytometry allowed to localize that the breakpoints were at the X-centromeric region and Xp11.3, respectively. These results show the usefulness of image analysis and fluorescence in situ hybridization for a rapid characterization of de novo structural chromosome anomalies in prenatal diagnosis.

Localization of the human coproporphyrinogen oxidase gene to chromosome band 3q12

The human gene encoding coproporphyrinogen oxidase is the defective gene in hereditary coproporphyria. This gene was mapped to chromosome band 3q12 using fluorescent in situ hybridization. The chromosomal localization was confirmed by cosegregation of the human gene with chromosome 3 in a panel of human/rodent somatic hybrids.

Evaluation of X, Y, 18, and 13/21 alpha satellite DNA probes for interphase cytogenetic analysis of uncultured amniocytes by fluorescence in situ hybridization

The major aneuploidies diagnosed prenatally involve the autosomes 13, 18, and 21, and sex chromosomes. Fluorescence in situ hybridization (FISH) allows rapid analysis of chromosome copy number in interphase cells. This prospective study evaluated the use of four commercially available centromeric DNA probes (DXZ1, DYZ1, D18Z1, and D13Z1/D21Z1) for direct analysis of uncultured amniocytes. One hundred and sixteen amniotic fluid samples were analysed by FISH and standard cytogenetics. This evaluation demonstrated that FISH with X, Y, and 18 alpha satellite DNA probes could accurately and rapidly detect aneuploidies involving these chromosomes and could be used in any prenatal clinical laboratory. In contrast, the 13/21 alpha satellite DNA probe hybridizing both chromosomes 13 and 21 was unreliable for prenatal diagnosis in uncultured amniocytes.

A simple method for prenatal diagnosis of trisomy 21 on uncultured amniocytes

Prenatal diagnosis of trisomy 21 would be easier if fluorescence in situ hybridization (FISH) could be applied to interphase nuclei. Therefore, we prepared a chromosome-21-specific probe by in vitro enzymatic amplification of inter-Alu sequences from YAC clones previously localized to this chromosome. This probe was used for FISH on 22 uncultured amniocyte samples. An easy, rapid, and safe technique is proposed for the prenatal diagnosis of trisomy 21.

Detection of 47,XYY trophoblast fetal cells in maternal blood by fluorescence in situ hybridization after using immunomagnetic lymphocyte depletion and flow cytometry sorting

Fluorescence in situ hybridization (FISH) allows to diagnose aneuploidy in uncultured interphase nuclei. This rapid method of chromosomal analysis associated with cell-sorting techniques was realized on 47,XYY fetal cells isolated from maternal blood. Trophoblast cells were sorted by combining immunomagnetic removal of maternal lymphocytes and flow cytometry sorting using antitrophoblast monoclonal antibodies. Cells were sorted directly on slides and analyzed by FISH with a Y-centromeric probe. Among 1,387 examinable nuclei, 59 (4.25%) showed one single or two Y-specific domains.

[Contribution of applied cytogenetics to medically assisted procreation]

The cytogenetic studies of gametes and embryos reveal the incidence of chromosomic abnormalities in medically assisted pregnancies. When extended to natural fecundation, these data enable a better comprehension of the place and the role of the selection in the quality of the conceptus.