"Il faut continuer à poser des questions" patient reported outcome measures in cystic fibrosis: An anthropological perspective

BACKGROUND

People with cystic fibrosis (pwCF) are central in the development of patient-led assessment tools. Qualitative analysis of a frequently used CF-specific patient-reported outcome measure (PROM) sought patient recommendations for development of a new quality of life (QoL) tool.

METHODS

We performed an inventory of PROMs, symptom-report and QoL tools used in clinical trials within the European Cystic Fibrosis Society Clinical Trial Network (ECFS-CTN) and in routine clinical practice among Cystic Fibrosis Europe and ECFS members. A qualitative study using cognitive interviews with pwCF and their caregivers reviewed the Cystic Fibrosis Questionnaire (CFQ), the French initial form of the Cystic Fibrosis Questionnaire-Revised (CFQ-R).

RESULTS

Survey results from 33 countries revealed over 70 tools used in routine clinical practice, utilized by clinical specialists (n=124), pwCF/parents/carers (n=49) and other allied health professionals (n=60). The CFQ-R was the main PROM used in clinical trials. The qualitative study enrolled 99 pwCF, 6 to 11 years (n=31); 12 to 18 years (n=38); >18 years (n=30) and 26 parents. Inductive thematic analysis based on the CFQ, revealed 19 key themes. Themes common across all cohorts included burden of treatment, impact of disease on day-to-day life, relationships/family, stress/mood, and nutrition. Themes unique to individual groups included, treatment when not symptomatic for the paediatric group; education/studies and planning for the future for adolescents, impact of anxiety and depression on day-to-day life for adults, and for parents, questions addressing anxiety and their role as carers.

CONCLUSIONS

Patient-centeredness is paramount in development of an up-to-date PROM in the era of novel therapies.

[Family support upon immediate cystic fibrosis announcement]

Cystic fibrosis, a rare, hereditary and chronic disease, affects the psychic functioning of children and their families. Since it is incurable, constant adjustments are essential to make sense of the inevitable evolution of the disease. The psychologists support the families and the patients so that all live as well as possible with cystic fibrosis.

Pain in children and adults with cystic fibrosis: a comparative study

Pain is a potential complication of cystic fibrosis (CF), but its consequences in daily life and other issues of pain management are not yet clearly understood. We undertook a comparative study of children and adults with CF to assess the prevalence of pain symptoms, their characteristics and treatment, their impact on daily quality of life, and the occurrence of procedural pain. The study included 73 children (1-18 years) and 110 adults (18-52 years); 59% of the children and 89% of the adults reported at least one episode of pain during the previous month. Pain was significantly more intense and lasted significantly longer among adults, but its rate and recurrence did not differ significantly between the two populations and were not related to the severity of CF. The most prevalent locations were the abdomen for children, and the back, head, and chest for adults. Although pain significantly limited physical activity, only 15% of patients reported that it caused absenteeism, and 27% reported that it negatively affected their family life. The mean pain intensity rates on a visual analog scale for the episode that had caused the greatest pain during the past month were 4.9 (2) (mean [SD]) for children and 6 (2) for adults; however, only 40% and 50%, respectively, of those with pain reported the use of analgesic treatment, mainly paracetamol (acetaminophen). At least one episode of procedural pain during the previous month was reported by 85% of children and 78% of adults. Our study demonstrates the high incidence of undertreated pain in CF patients throughout their lives.

Spatial and temporal mapping of c-kit and its ligand, stem cell factor expression during human embryonic haemopoiesis

Receptor tyrosine kinases (RTKs) mediate cellular responses to the extracellular signals involved in the regulation of cell differentiation and proliferation. Ligand binding initiates a cascade of events, such as receptor dimerization and tyrosine phosphorylation. The c-kit gene encodes an RTK for stem cell factor (SCF), (c-kit ligand, KL), both of which play a critical role in the differentiation and growth of haemopoietic stem cells (HSCs). We investigated the expression of the c-kit and SCF genes and the presence of the corresponding proteins in haemopoietic tissues during human embryogenesis. We have examined c-kit and SCF transcripts levels in human embryonic yolk sac, the AGM region, and liver at different stages of gestation (days 25 to 63), using RT-PCR amplification combined with PhosphorImager quantitative analysis and RNase Protection Assay (RPA). Weak levels of SCF gene expression were observed in the AGM region (days 25 to 34) and high levels were found in the early-stage liver (day 34). The expression of c-kit transcript was observed in all studied tissues, but at various levels. The restricted presence of SCF protein following mRNA expression was demonstrated in embryonic liver CD38+ haemopoietic cells by immunocytochemistry. These observations suggest that the biological function of the c-kit receptor plays an important role in the early stages of human haemopoiesis, and that c-kit/SCF signalling is particularly involved in early human definitive haemopoiesis.

Molecular and immunologic aspects of the nonclassical HLA class I antigen HLA-G: evidence for an important role in the maternal tolerance of the fetal allograft

PROBLEM

Human leukocyte antigen (HLA)-G is a major histocompatibility complex class I antigen, which is referred to as nonclassical because it displays a tissue-restricted distribution in the placenta, a reduced cytoplasmic domain, a limited polymorphism, and several isoforms. The HLA-G antigen is thought to play an essential role during pregnancy by protecting the semi-allogeneic fetus from recognition and destruction by maternal immune cells.

METHOD OF STUDY

Alternative splicing of HLA-G mRNA was analyzed by Southern blot of reverse transcriptase-polymerase chain reaction products from trophoblasts of the first trimester of gestation and term placenta. The regulation of HLA-G gene expression was investigated by electrophoretic mobility shift assays using nuclear extracts from cells expressing different levels of HLA-G gene activity. Using polymerase chain reaction-single strand conformational polymorphism and sequencing, we studied HLA-G gene polymorphism in families from the Centre d'Etude du Polymorphisme Humain in Paris. To understand the function of the HLA-G molecule, cytotoxicity assays were carried out with peripheral blood mononuclear cells or polyclonal natural killer effectors cells from 30 different donors against HLA-G1 and HLA-G2 transfectants.

RESULTS

Four main aspects have been elucidated: 1) The primary transcript of the HLA-G gene is alternatively spliced into five main mRNA forms: HLA-G1 (full length), HLA-G2 (minus exon 3), which encodes a membrane-bound isoform associated with beta-2 microglobulin, HLA-G3 (minus exons 3 and 4), HLA-G4 (minus exon 4), and HLA-G5 (plus intron 4), which encodes a soluble form of the HLA-G antigen; 2) specific nuclear factors bind to an important regulatory element located more than 1.2 kb from the HLA-G gene. Three specific complexes are observed in cells that show HLA-G transcriptional activity and an additional factor that could correlate with the repression of HLA-G gene expression that is detected in natural killer cells; 3) we observed an important genomic polymorphism in exon 3 but a very low polymorphism at the protein level; 4) HLA-G1 and HLA-G2 transfectants clearly demonstrated that both HLA-G isoforms are capable of inhibiting natural killer lytic activity.

CONCLUSION

These results suggest that HLA-G acts as the public ligand for natural killer inhibitory receptors, thus protecting the fetus against maternal rejection.

The alpha1 domain of HLA-G1 and HLA-G2 inhibits cytotoxicity induced by natural killer cells: is HLA-G the public ligand for natural killer cell inhibitory receptors?

We have investigated the protective role of the membrane-bound HLA-G1 and HLA-G2 isoforms against natural killer (NK) cell cytotoxicity. For this purpose, HLA-G1 and HLA-G2 cDNAs were transfected into the HLA class I-negative human K562 cell line, a known reference target for NK lysis. The HLA-G1 protein, encoded by a full-length mRNA, presents a structure similar to that of classical HLA class I antigens. The HLA-G2 protein, deduced from an alternatively spliced transcript, consists of the alpha1 domain linked to the alpha3 domain. In this study we demonstrate that (i) HLA-G2 is present at the cell surface as a truncated class I molecule associated with beta2-microglobulin; (ii) NK cytolysis, observed in peripheral blood mononuclear cells and in polyclonal CD3(-) CD16(+) CD56(+) NK cells obtained from 20 donors, is inhibited by both HLA-G1 and HLA-G2; this HLA-G-mediated inhibition is reversed by blocking HLA-G with a specific mAb; this led us to the conjecture that HLA-G is the public ligand for NK inhibitory receptors (NKIR) present in all individuals; (iii) the alpha1 domain common to HLA-G1 and HLA-G2 could mediate this protection from NK lysis; and (iv) when transfected into the K562 cell line, both HLA-G1 and HLA-G2 abolish lysis by the T cell leukemia NK-like YT2C2 clone due to interaction between the HLA-G isoform on the target cell surface and a membrane receptor on YT2C2. Because NKIR1 and NKIR2, known to interact with HLA-G, were undetectable on YT2C2, we conclude that a yet-unknown specific receptor for HLA-G1 and HLA-G2 is present on these cells.

[Fetomaternal tolerance: role of HLA-G molecule in the protection of the fetus against maternal natural killer activity]

HLA-G is a non-classical major histocompatibility complex class I molecule selectively expressed on extravillous trophoblast cells at the fetal-maternal interface. HLA-G may play an important role in maintaining maternal immune tolerance of the semi-allogenic fetus. In this study, we demonstrate for the first time the protective role of HLA-G during pregnancy. Indeed, cytotrophoblast cells of the fetus are resistant to lytic activity by maternal decidual natural killer cells. In order to precisely characterize the immunological functions of HLA-G products, we have investigated the protective role of the membrane-bound HLA-G1 and HLA-G2 isoforms against NK cell cytotoxicity. For this purpose, HLA-G1 and HLA-G2 cDNAs were transfected into the HLA-class I negative human K562 cell line. We demonstrate that both HLA-G1 and HLA-G2 transfectants inhibit NK cytolysis observed in peripheral blood from 25 donors (males and females). This led us to the conjecture that HLA-G is the public ligand for natural killer inhibitory receptors present in all individuals.

HLA-G gene polymorphism segregation within CEPH reference families

HLA-G, a nonclassical HLA class I antigen, presents tissue-restricted expression on human trophoblasts and may play an important role in immune tolerance of mother-versus-fetus. In this work we have demonstrated extensive HLA-G genomic polymorphism within three CEPH reference families, by PCR-SSCP analysis and direct sequencing. Among six unrelated parents we assigned eight HLA-G alleles, seven of which are new. We observed the segregation of HLA-G alleles of heterozygous parents among their offspring that matched the segregation of the HLA class I haplotypes. Only one of the mutations observed was found to be nonsynonymous indicating low polymorphism of the HLA-G molecule.

HLA-G gene transcriptional regulation in trophoblasts and blood cells: differential binding of nuclear factors to a regulatory element located 1.1 kb from exon 1

The HLA-G antigen is specifically expressed on trophoblasts at the maternal-fetal interface, while expression of classical class I HLA-A, -B, -C products is repressed in this tissue. The transcriptional level of the HLA-G gene is high in trophoblast cells and in JEG-3 choriocarcinoma cells, is markedly reduced in blood cells, and is shown here to be undetectable in the YT2C2 NK cell line. In an attempt to understand molecular mechanisms controlling cell-specific transcriptional regulation of the HLA-G gene in these cells, we focused our study on protein interaction with a 244-bp region located over 1.1 kb from exon 1, which has been shown to direct HLA-G expression in transgenic mouse trophoblast. Three specific complexes were detected, two of which are found exclusively in cells showing HLA-G transcriptional activity. The YT2C2 nuclear extracts contain restricted DNA-binding activity of an additional factor which could correlate with repression of HLA-G transcription in these cells.

Characterization of ovine SRY transcript and developmental expression of genes involved in sexual differentiation

In mammals, the presence of SRY, the sex-determining gene located on the Y chromosome is required to induce the gonadal anlage to differentiate as a testis, whereas its absence leads to the development of an ovary. We report here the characterization by 5' and 3' RACE analysis of several SRY transcripts which are expressed in the ovine male developing gonads. These transcripts were not detected in any other fetal tissues and were expressed only in the genital portion of the urogenital ridge. The temporal profile of SRY expression analyzed by RT-PCR suggests that in the sheep fetus the role of SRY is not limited to initiating Sertoli cell differentiation as in mice. Indeed, SRY transcripts persist after the full differentiation of the testis. In addition to SRY, other genes are known to be involved in mammalian sex determination: Wilms' tumor gene WT-1, steroidogenic factor gene Ftz-F1 (SF-1) and anti-Müllerian hormone (AMH). We investigated the expression patterns of these genes by RT-PCR during fetal development in sheep gonads. Concerning WT-1 and SF-1, our results are consistent with those described in mice where the earliest expression was detected before the sexual differentiation in both sexes. In male, the ontogenesis of AMH transcription corresponds to the seminiferous cords formation (30 dpc). In female, we have observed the presence of SF-1 transcripts from the undifferentiated stage until birth. In addition, P450 aromatase expression is detected from 30 dpc and is correlated with the presence of 17-beta estradiol in sheep ovary. These data reveal significant differences between rodent and ruminant models concerning the sex-determining pathway.

Natural killer cells are the unique lymphocyte cell subset which do not express HLA-G

In order to better understand the immunological functions of the HLA-G gene, expression of this gene has been studied with RT-PCR in human functional lymphocyte subpopulations. Only one population of cells has not shown any HLA-G mRNA expression, the BY55-mAb-defined natural killer cells in cord blood. This absence of transcription was not modulated by IL2, IFN-gamma or TNF-alpha. Several T clone lymphocytes isolated from human peripheral blood, bone marrow or thymus have shown a significant transcription of the HLA-G gene. Only one clone, with a natural killer phenotype, did not reveal full length or alternatively spliced transcripts of HLA-G. Intensity of HLA-G transcription was not affected by TNF-alpha, IL13 or IL4, but HLA-G transcripts appeared more abundant in the presence than in the absence of IL2.

[Alternative transcripts of the MHC of the non-classical class I HLA-G gene in the in trophoblast during the first pregnancy trimester and in the placenta at term]

HLA-G, a non-classical class I gene, is located within the human major histocompatibility complex locus. It has a tissue-specific expression in trophoblast, where the products of HLA-A, -B and -C classical genes are absent. Therefore, the HLA-G gene may have a role during pregnancy in inducing protection of the semi-allogeneic fetus from recognition and destruction by maternal immune cells. The primary transcript of the HLA-G gene is alternatively spliced into 6 mRNA forms (HLA-G1 to HLA-G6), 2 of them may encode soluble forms of the HLA-G antigen (HLA-G5 and HLA-G6). In this work, by using reverse transcription polymerase chain reaction technique, we demonstrate that all transcripts are detected in similar amounts, both in the first and third trimester of gestation. These results are discussed in context of putative function of HLA-G antigen isoforms.

Soluble HLA-G molecule. An alternatively spliced HLA-G mRNA form candidate to encode it in peripheral blood mononuclear cells and human trophoblasts

The HLA-G nonclassic MHC class I gene expressed at the maternal-fetal interface may be involved in cell protection against NK cell lysis. HLA-G mRNA is observed in different adult or fetal human cells and exhibits four alternative forms: HLA-G1, HLA-G2, HLA-G3, and HLA-G4 lacking, respectively, exon 7; exons 7 and 3, exons 7, 3, and 4; exons 7 and 4. Because exon 5 encodes the transmembrane domain of the HLA-G antigen, none of these transcripts could give a soluble form as detected in supernatant of trophoblasts. In this report, we describe an additional alternatively spliced for of HLA-G transcript (HLA-G5) present in adult PBMCs and first-trimester trophoblasts that contains intron 4. Moreover, as with all other transcripts, HLA-G5, is devoid of exon 7. Its relative frequency is, respectively, approximately 1:8 and approximately 1:26 in adult PBMCs and first-trimester trophoblasts. The presence of intron 4 generates a stop codon that excludes transmembrane region (exon 5) of the HLA-G molecule and therefore might produce a soluble antigen. These results are discussed with regard to data on soluble forms of classic HLA antigens and the possible role of HLA-G.

Evidence for the presence of the alternatively spliced HLA-G mRNA forms in human mononuclear cells from peripheral blood and umbilical cord blood

The HLA-G monomorphic, nonclassic HLA class I gene encodes the molecule that is the only major histocompatibility complex antigen expressed on cytotrophoblasts of placenta. This restricted expression on fetal tissue that is in contact with maternal tissue suggests that HLA-G products may play a role in maternofetal tolerance. We previously have demonstrated in first-trimester human trophoblasts a new alternatively spliced form of HLA-G mRNA lacking exon 4 (HLA-G4) and weak expression of HLA-G1 copy mRNA in adult peripheral blood lymphocytes. By using exon-specific HLA-G primers, we demonstrate in this work the presence of three additional alternatively spliced forms of HLA-G mRNA in human peripheral mononuclear cells (HLA-G2, HLA-G3, and HLA-G4). In umbilical cord blood, HLA-G transcription was observed at very low level and only three alternatively spliced forms were detected (HLA-G1, HLA-G2, and HLA-G3). In contrast, we did not revealed any HLA-G transcript in CD34+ fraction of cord blood cells.

Cloning and characterization of a full-length cDNA coding for ovine aldolase B from fetal mesonephros

An ovine aldolase B cDNA was isolated from mesonephros (29 d pc). The sequence covers 1649 nucleotides. Comparison with human liver aldolase B cDNA shows a homology of about 86%. The deduced amino acid sequence is composed of 364 residues and exhibits 92% homology to the human protein. Northern blot analysis and in situ hybridization data show that during the first third of gestation in sheep, aldolase B expression is restricted to the mesonephros.

An alternatively spliced form of HLA-G mRNA in human trophoblasts and evidence for the presence of HLA-G transcript in adult lymphocytes

The HLA-G monomorphic, nonclassical class I gene encodes the major histocompatibility complex (MHC) molecule, which is the only MHC antigen expressed on cytotrophoblast cells of placenta. In this work, we have investigated expression of the HLA-G gene in fetal tissues and adult peripheral blood cells by using a sensitive hot-start reverse transcriptase PCR technique. PCR amplification with HLA-G primers specific for exon 3 has enabled us to demonstrate an alternatively spliced form of HLA-G mRNA present in fetal first trimester trophoblasts and lacking exon 4 (HLA-G.3-5). This low abundance transcript (approximately 1:200) in comparison to full-length mRNA may encode the protein that excludes the alpha 3 domain and by conformational changes may present a different ability to bind to peptides. Moreover, expression of the HLA-G transcript was found in adult peripheral lymphocytes and equally in B- and T-cell populations. These results are discussed in the context of the fetal-maternal relationship presented by HLA-G gene products.

Improvement of flow cytometry analysis and sorting of bull spermatozoa by optical monitoring of cell orientation as evaluated by DNA specific probing

Flow cytometry is a potential method for the separation of X and Y bearing spermatozoa, on the basis of their relative DNA content evaluated by the fluorescence emission intensity due to specific fluorochrome DNA staining. However, spermatozoa DNA is highly condensed and nuclei exhibit flat non spherical shape, which can produce artefacts impeding accurate analysis. In order to avoid these limitations, decondensation of DNA performed by enzymatic treatment and a modification of the flow cytometer that orients the spermatozoa relative to the laser beam are generally used. In this work, we describe alternative methods and materials for selection of 1) decondensed and thus dead spermatozoa without orientation, sorted on the basis of only the 10% spermatozoa containing the least DNA (expected Y) and the 10% spermatozoa containing the more DNA (expected X), or 2) native spermatozoa homogeneously oriented using a simultaneous measurement of Axial light loss (extinction) and Forward angle light scatter. For testing enrichment of each selected fraction we have worked out a molecular hybridization procedure using X and Y specific DNA probes. We analyse and sort bull spermatozoa on these basis: the purity obtained for these fractions is 80% without orientation after enzymatic treatment, and 70% on live spermatozoa "optically" oriented.

Isolation of bovine Y-derived sequence: potential use in embryo sexing

To obtain bovine Y-derived probes, we have constructed a bovine plasmid library enriched for Y-specific DNA sequences by the deletion enrichment method. The resulting clones were analyzed by hybridization to Southern blots of male and female genomic DNA. From 200 clones tested, two (BC1.2 and BC1.34) were entirely male specific, six gave a male-female differential hybridization pattern, and the remaining reacted similarly with male and female DNA. Interspecies somatic cell hybrid studies and chromosomal in situ hybridization confirmed that the BC1.2 sequence was derived from the Y chromosome. This 54-bp fragment is present at about 2000-2500 copies in the bovine male genome. No polymorphism was revealed with any of the restriction enzymes used, suggesting enzyme site conservation within blocks of repeats. Evolutionary study has shown that the BC1.2 sequence is conserved within Bos and Bison genera and remains male specific. The male specificity and repeated nature of the BC1.2 sequence have enabled us to use it as a molecular probe for sex determination on small numbers of cells by in situ hybridization.

Analysis of the sheep MHC using HLA class I, II, and C4 cDNA probes

Four cDNA probes for the human major histocompatibility complex (MHC) were used to investigate the sheep MHC, in conjunction with serological typing for ovine lymphocyte antigen (OLA). Lymphocytes from a family (two parents and five offspring) of Romanov sheep were subjected to genomic DNA digestion by the restriction endonuclease Eco RI, followed by gel electrophoresis. A single Southern blot representing all seven individuals was then consecutively hybridized with the class I, alpha-DC, beta-DR, and C4 probes, which were originally designed to identify HLA class I, class II (DC and DR), and C4 products, respectively. Using each of the three class I/class II probes, several bands showing DNA polymorphism were detected. The segregation of these bands in the five offspring exactly paralleled the OLA haplotype segregation established by serological typing. A further eight individuals carrying haplotypes which were phenotypically identical to those in the above-mentioned family showed bands in the corresponding positions when tested with the same three probes. Using the C4 probe, no polymorphism was detected in these fifteen individuals.

Molecular genetic analyses of the major histocompatibility complex in pig families and recombinants

Five HLA probes, one corresponding to class I genes, two corresponding to distinct class II light chain genes, DR beta and DQ beta, and two to class II heavy chain genes, DR alpha and DQ alpha, were used to analyse the genomic DNA of the pig. Three informative SLA typed families and four SLA recombinants were studied by Southern blot analysis. About 16 restriction fragments, generated by EcoR1 or Hind III endonucleases, were revealed for each individual, either with the class I probe or the DR beta probe. The number of restriction fragments which hybridized with the other probes was generally lower. Several restriction fragment-length polymorphisms were found and these segregated with SLA haplotypes. The studies on SLA recombinants showed that SLA DR beta- and DQ alpha-like genes are probably tightly clustered within the SLA-D-MLR region.

Restriction fragment length polymorphism of the major histocompatibility complex of the pig

Human HLA cDNA probes were used to analyze the restriction fragment length polymorphism (RFLP) of the SLA major histocompatibility complex in swine. Cellular genomic DNA from 19 SLA homozygous pigs representing 13 different haplotypes was digested with restriction endonucleases Eco R1, Hind III, or Bam H1, separated by electrophoresis, and transferred onto diazobenzyloxymethyl paper by the Southern blot technique. The blots were probed with 32P-labeled class I or beta-DR class II cDNA. Depending on the haplotypes and the endonucleases used, seven to ten restriction fragments hybridized with the class I probe, and five to seven with the beta-DR probe. Their sizes ranged from 3.4 to 22 kilobase-pairs. Few bands were common to all 13 haplotypes. With all but one haplotype, identical autoradiogram patterns were obtained from unrelated, but phenotypically SLA-identical pigs, suggesting that most of the RFLP revealed were controlled by the SLA region. Further polymorphism was found in a group of seven unrelated pigs which typed serologically as SLA A15 C1 B18 homozygotes but could be divided into two subgroups, with five animals in one subgroup and two in the other, when the genomic DNA was hybridized with the class I probe. When the class II beta-DR probe was tested on the same seven pigs, another subdivision was seen, and this correlated with MLR data. These results demonstrate that HLA class I and class II probes can be used to identify certain well-established SLA haplotypes and to identify subclasses within at least one SLA haplotype.