Confident Perception of Primary Care Physicians Correlates to the Attitude Toward Donation and Organ Transplantation: A Multicenter Study of Medical And Nursing Spanish Students

A primary care physician (PCP) not only accompanies the patient in the process of an illness, but throughout his or her life. The confidence we have in these health professionals is fundamental, and their favorable attitude toward organ donation and transplantation (ODT) has a significant influence on the population.

OBJECTIVE

To analyze trust in PCPs among Spanish medical and nursing students, the relationship with their attitude toward ODT, and the factors that condition it.

METHODS AND DESIGN

A sociologic, multicenter, and observational study.

POPULATION

medical and nursing students in Spanish universities.

DATABASE

Collaborative International Donor Project, stratified by geographic area and academic course. A validated questionnaire (PCID-DTO-RIOS) was self-administered and completed anonymously. A sample of 9598 medical and 10,566 nursing students (99% confidence and precision of ±1%), stratified by geographic area and year of study.

RESULTS

Completion rate: 90%. With respect to students' trust in their physician, 18% (n = 3267) of them totally trust (completely), 45% (n = 8101) trust enough, 30% (n = 5478) of them have not enough trust, and 7% not at all. Comparing groups, medical students totally trust more in PCPs than nursing students (55% vs 45%; P < .000), however, nursing students have less than enough trust in their PCP than medical students (53% vs 47%; P < .000). Students that totally trust in their PCP were more in favor toward ODT than students with not enough trust (83% vs 77%; P < .000).

CONCLUSION

Only 18% of Spanish medical and nursing students totally trust in their PCP. Attitude toward ODT is related to a higher level of trust in PCPs among these students.

What Reasons Lead Spanish Medical Students Not to Be in Favor of Organ Donation?

INTRODUCTION

Despite sensitization of medical students toward the donation of organs, a non-negligible percentage of students are not in favor of donation.

OBJECTIVE

To analyze the reasons of Spanish medical students who do not have a favorable attitude toward the donation of their own organs after death.

METHOD

The population under study is medical students in Spanish universities, using the database of the International Donor Collaborative Project, stratified by geographic area and academic year. The questionnaire completion was anonymous and self-administered. The study group is medical students with an unfavorable attitude toward organ donation. The assessment instrument used is a validated questionnaire of attitude toward the donation of organs for transplant, "PCID-DTO-Ríos." The reasons against the donation are valued in the questionnaire through a question.

RESULTS

Of the participants included in the PCID, students who are not in favor of organ donation were selected (n = 1899). Of them, 8.1% (n = 154) are against and 91.1% (n = 1745) are doubtful. The main reasons indicated are the fear of apparent death in 11.4% of respondents, fear of possible mutilation after donation in 11.1%, and religious reasons in 2.6%. Of those, 6.9% indicate other reasons but do not clearly specify the reasons, using words such as "fear" (2.5%) or "doubts about the process" (4.1%); 66.2% (n = 1257) indicated an "assertive refusal" ("I don't want to express my reasons").

CONCLUSION

Twenty percent of Spanish medical students are not in favor of donating their organs and are not in favor of showing their reasons.

Are Medical Students of Non-Spanish Nationality Studying in Spain as Sensitized to Transplantation as Those of Spanish Nationality?

INTRODUCTION

Awareness of organ donation among Spanish doctors and medical students is very positive. However, the emerging group of professionals of non-Spanish nationality studying in Spain has not been analyzed.

OBJECTIVE

To analyze the differences in the attitudes toward the different types of donation among medical students, according to their nationality.

METHODS

The population under study is medical students in Spanish universities using the database of the International Collaborative Donor Project, stratified by geographic area and academic year. Groups under study include students of non-Spanish nationality as group 1 (n = 1570) and students of Spanish nationality as Group 2 (n = 7705). Instruments are validated questionnaires of attitude toward donation "PCID-DTO-Ríos," "PCID-DVR-Ríos," "PCID-DVH-Ríos," and "PCID-XenoTx-Ríos."

RESULTS

The attitude toward the donation of own organs after death is similar in both groups (P = .703). Non-Spaniards are 79.2% in favor compared to 79.6% of Spaniards. Living kidney donation, both unrelated (33.3% vs 29.3% in favor; P = .001) and related (91.2% vs 89, 6% in favor; P = .047), is more favorable among non-Spanish students. There are no differences regarding non-related living liver donation (29.7% vs 29.3% in favor; P = .063), but there are differences in the results for related living liver donation (94.1% vs 88%; P < .001). The attitude toward xenotransplantation of organs is similar (80.8% vs 80.8%; P = .999).

CONCLUSIONS

Awareness of the donation of organs among Spanish medical students is similar to non-Spanish students studying in Spain, except the attitude toward living donation.

Information About Donation and Organ Transplantation Among Spanish Medical Students

INTRODUCTION

Health professionals are asked to promote health, especially organ transplantation; however, they do not always have specific training.

OBJECTIVE

To analyze information about donation and organ transplantation among Spanish medical students.

METHOD

The population under study is medical students in Spanish universities using the database of the International Donor Collaborative Project, stratified by geographic area and academic year (n = 9275). The instrument used is the attitude questionnaire for organ donation for "PCID-DTO-Ríos" transplantation, validated with an explained variance of 63.203% and α = 0.834. The Student t test was applied together with the χ² test, complemented by an analysis of the remainders, and Fisher's exact test was applied.

RESULTS

Of the students, 74% indicate that they have received information from university professors about organ transplant. Concerning specific issues with the donation, it is notable that only 66.7% (n = 6190) know and accept the concept of brain death as the death of a person. However, only 22% consider themselves as having good information, and 35.3% indicate that their information is scarce or void. Students indicate having received information about transplant from other extra-university sources, such as television and Internet (80.9%), books and magazines (73.2%), and the press (66.9%). From the information obtained in the sociofamilial field, 60.7% have obtained information from the family and 58.1% from friends. Of this information, 9% has been negative from friends, 7.5% from family, 6% from the Internet and television, and 4% from university professors.

CONCLUSION

Spanish medical students believe they have little information about organ transplantation and have received negative information.

LOXL2-mediated H3K4 oxidation reduces chromatin accessibility in triple-negative breast cancer cells

Oxidation of H3 at lysine 4 (H3K4ox) by lysyl oxidase-like 2 (LOXL2) generates an H3 modification with an unknown physiological function. We find that LOXL2 and H3K4ox are higher in triple-negative breast cancer (TNBC) cell lines and patient-derived xenografts (PDXs) than those from other breast cancer subtypes. ChIP-seq revealed that H3K4ox is located primarily in heterochromatin, where it is involved in chromatin compaction. Knocking down LOXL2 reduces H3K4ox levels and causes chromatin decompaction, resulting in a sustained activation of the DNA damage response (DDR) and increased susceptibility to anticancer agents. This critical role that LOXL2 and oxidized H3 play in chromatin compaction and DDR suggests that functionally targeting LOXL2 could be a way to sensitize TNBC cells to conventional therapy.

A Multicentre and stratified study of the attitude of medical students towards organ donation in Spain

INTRODUCTION

Medical students represent a new generation of medical thought, and if they have a favourable attitude towards organ donation this will greatly encourage its promotion.

OBJECTIVE

To analyse the attitude of medical students in Spanish universities towards the donation of their own organs and to determine the factors affecting this attitude.

MATERIAL AND METHODS

Type of study: A sociological, interdisciplinary, multicentre, and observational study in Spain.

STUDY POPULATION

Students studying a degree in medicine enrolled in Spain (n = 34,000).

SAMPLE SIZE

A sample of 9598 students (confidence of 99% and precision of ±1%), stratified by geographical area and academic year. Instrument of measurement: A validated questionnaire of attitude towards organ donation and transplantation (PCID-DTO RIOS) was self-administered and completed anonymously.

RESULTS

The questionnaire completion rate was 95.7% (n = 9.275). 80% were in favour of donation, 2% against and 18% were undecided. The following main variables were related to a favourable attitude: being of the female sex (Odds Ratio = 1.739); being in the sixth year of the degree (OR = 2.506); knowing a donor (OR = 1.346); having spoken about the subject with one's family (OR = 2.132) and friends (OR = 1.333); having a family circle that is in favour, more specifically, having a father (OR = 1.841), mother (OR = 2.538) or partner in favour (OR = 2.192); being a blood donor (OR = 2.824); acceptance of the mutilation of the body if it were necessary (OR = 2.958); and being an atheist or an agnostic (OR = 1.766).

CONCLUSIONS

Spanish medical students generally have a favourable attitude towards organ donation, although 20% are not in favour.

Sensitization Toward Organ Donation Among Medical Students in Spanish Regions With More Than 50 Donors Per Million Population

The awareness of organ donation among health professionals is important at the time of transplant promotion. In this sense, the training and awareness of the professionals in training is fundamental.

OBJECTIVE

To analyze the differences in the attitude toward organ donation and the factors that condition it among medical students of regions with donation rates >50 donors per million population (pmp) with respect to those with rates <40 donor pmp.

METHOD

Population under study: medical students in Spanish universities. Database of the Collaborative International Donor Project, stratified by geographic area and academic course. The completion was anonymous and self-administered. Groups under study: Group 1 (n = 1136): students in universities of regions with >50 donors pmp. Group 2 (n = 2018): university students in regions with <40 donors pmp. Assessment instrument: attitude questionnaire for organ donation for transplant PCID-DTO-Ríos.

RESULTS

The attitude toward organ donation for transplantation is similar among students from the autonomous communities with >50 donors pmp and with <40 donors pmp. In group 1, 79% (n = 897) of students are in favor compared with 81% (n = 1625) of group 2 (P=.29). The psychosocial profile toward donation is similar in both groups relating to the following variables (P < .05): sex, having discussed transplantation with family and as a couple, considering the possibility of needing a transplant, involvement in prosocial activities, attitude toward the manipulation of corpses, knowledge of the brain death concept, and religion.

CONCLUSIONS

The awareness of organ donation in Spanish medical students is quite homogeneous and is not related to the local donation rates of each region.

Do Spanish Medical Students Understand the Concept of Brain Death?

Objective:

To analyze the level of understanding of the brain death concept among medical students in universities in Spain.

Methods:

This cross-sectional sociological, interdisciplinary, and multicenter study was performed on 9598 medical students in Spain. The sample was stratified by geographical area and academic year. A previously validated self-reported measure of brain death knowledge (questionnaire Proyecto Colaborativo Internacional Donante sobre la Donación y Transplante de Organos) was completed anonymously by students.

Results:

Respondents completed 9275 surveys for a completion rate of 95.7%. Of those, 67% (n = 6190) of the respondents understood the brain death concept. Of the rest, 28% (n = 2652) did not know what it meant, and the remaining 5% (n = 433) believed that it did not mean that the patient was dead. The variables related to a correct understanding of the concept were: (1) being older ( P < .001), (2) studying at a public university ( P < .001), (3) year of medical school ( P < .001), (4) studying at one of the universities in the south of Spain ( P = .003), (5) having discussed donation and transplantation with the family ( P < .001), (6) having spoken to friends about the matter ( P < .001), (7) a partner’s favorable attitude toward donation and transplantation ( P < .001), and (8) religious beliefs ( P < .001).

Conclusions:

Sixty-seven percent of medical students know the concept of brain death, and knowledge improved as they advanced in their degree.

Transcriptome analysis of severely active chronic spontaneous urticaria shows an overall immunological skin involvement

BACKGROUND

The knowledge about chronic spontaneous urticaria (CSU) phenotypes is based on its clinical characteristics, associated comorbidities, course of the disease, and its response to the available effective drugs. Genotype expression and its further correlation with CSU phenotypes are still unknown. We describe the cutaneous transcriptome of patients suffering a severely active CSU refractory to antihistamine treatment.

METHODS

Through the bioinformatic analysis of the whole Human Genome with Oligo Microarrays and quantitative real-time polymerase chain reaction (qPCR), relevant genes expressed in nonlesional (NLS-CSU) and lesional skin (LS-CSU) and peripheral blood were identified in 20 patients suffering from severely active CSU and 10 healthy controls (HCs).

RESULTS

From 39 genes differentially expressed in NLS-CSU when compared with HCs, 31 (79.48%) were confirmed by qPCR corresponding to genes involved in epidermal homeostasis and dermal repair. From the analysis comparing LS-CSU with NLS-CSU, a selection of 142 genes was studied with qPCR, and 103 (72.53%) were confirmed. Differentially expressed genes in the phenomenon of wheal development are involved in a variety of biological functions as, epidermal differentiation, intracellular signal function, transcriptional factors cell cycle differentiation, inflammation, or coagulation. Differentially expressed genes that uniformly increase or decrease along the skin worsening until the wheal appearance is shown.

CONCLUSION

The skin of CSU patients with a severely active disease shows an overall immunological skin involvement showing a peculiar gene profile.

Circulating NK-cell subsets in renal allograft recipients with anti-HLA donor-specific antibodies

Detection of posttransplant donor-specific anti-HLA antibodies (DSA) constitutes a risk factor for kidney allograft loss. Together with complement activation, NK-cell antibody-dependent cell mediated cytotoxicity (ADCC) has been proposed to contribute to the microvascular damage associated to humoral rejection. In the present observational exploratory study, we have tried to find a relationship of circulating donor-specific and non donor-specific anti-HLA antibodies (DSA and HLA non-DSA) with peripheral blood NK-cell subsets and clinical features in 393 renal allograft recipients. Multivariate analysis indicated that retransplantation and pretransplant sensitization were associated with detection of posttransplant DSA. Recipient female gender, DR mismatch and acute rejection were significantly associated with posttransplant DSA compared to HLA non-DSA. In contrast with patients without detectable anti-HLA antibodies, DSA and HLA non-DSA patients displayed lower proportions of NK-cells, associated with increased CD56(bright) and NKG2A(+) subsets, the latter being more marked in DSA cases. These differences appeared unrelated to retransplantation, previous acute rejection or immunosuppressive therapy. Although preliminary and observational in nature, our results suggest that the assessment of the NK-cell immunophenotype may contribute to define signatures of alloreactive humoral responses in renal allograft recipients.

Loss of PIDD limits NF-κB activation and cytokine production but not cell survival or transformation after DNA damage

Activation of NF-κB (nuclear factor of kappa light chain gene enhancer in B cells) in response to DNA damage is considered to contribute to repair of genetic lesions, increased cell survival and cytokine release. The molecular mechanisms orchestrating this cytoplasmic event involve core components of the nuclear DNA damage response machinery, including ATM-kinase (ataxia telangiectasia mutated kinase) and PARP-1 (poly (ADP-ribose) polymerase 1). The physiological consequences of defective NF-κB activation in this context, however, remain poorly investigated. Here we report on the role of the 'p53-induced protein with a death domain', PIDD, which appears rate limiting in this process, as is PARP-1. Despite impaired NF-κB activation, DNA damage did not increase cell death or reduce clonal survival of various cell types lacking PIDD, such as mouse embryonic fibroblasts or stem and progenitor cells of the hematopoietic system. Furthermore, lymphomagenesis induced by γ-irradiation (IR) was unaffected by deficiency for PIDD or PARP-1, indicating that loss of DNA damage-triggered NF-κB signalling does not affect IR-driven tumorigenesis. However, loss of either gene compromised cytokine release after acute IR injury. Hence, we propose that NF-κB's most notable function after DNA damage in primary cells is related to the release of cytokines, thereby contributing to sterile inflammation.

Nuclear PARP-1 protein overexpression is associated with poor overall survival in early breast cancer

BACKGROUND

Poly(ADP-ribose)polymerase-1 (PARP-1) is a highly promising novel target in breast cancer. However, the expression of PARP-1 protein in breast cancer and its associations with outcome are yet poorly characterized.

PATIENTS AND METHODS

Quantitative expression of PARP-1 protein was assayed by a specific immunohistochemical signal intensity scanning assay in a range of normal to malignant breast lesions, including a series of patients (N = 330) with operable breast cancer to correlate with clinicopathological factors and long-term outcome.

RESULTS

PARP-1 was overexpressed in about a third of ductal carcinoma in situ and infiltrating breast carcinomas. PARP-1 protein overexpression was associated to higher tumor grade (P = 0.01), estrogen-negative tumors (P < 0.001) and triple-negative phenotype (P < 0.001). The hazard ratio (HR) for death in patients with PARP-1 overexpressing tumors was 7.24 (95% CI; 3.56-14.75). In a multivariate analysis, PARP-1 overexpression was an independent prognostic factor for both disease-free (HR 10.05; 95% CI 5.42-10.66) and overall survival (HR 1.82; 95% CI 1.32-2.52).

CONCLUSIONS

Nuclear PARP-1 is overexpressed during the malignant transformation of the breast, particularly in triple-negative tumors, and independently predicts poor prognosis in operable invasive breast cancer.

Local identification of porcine haptoglobin in salivary gland and diaphragmatic muscle tissues

In order to clarify the origin of the haptoglobin (Hp) quantified in saliva and meat juice samples, the extrahepatic localization of Hp in salivary gland and in diaphragmatic muscle, as part of the systemic acute phase response in pigs, was studied by immunohistochemistry. For this purpose a specific monoclonal antibody (mAb) produced by immunising mice with purified porcine Hp was used. Reactivity of the mAb was assessed by direct ELISA and by western blot, which showed the ability and specificity of the mAb to identify porcine haptoglobin as a purified antigen or in porcine serum in a native or denatured but non-reduced state. Five healthy and five diseased pigs were sampled at slaughter for serum and tissue procurement. Hepatic immunohistochemical analysis was used as control of the acute phase reaction status. In the liver, cell immunostaining revealed a perinuclear, cytoplasmic localization of Hp within hepatocytes, following mainly a periacinar pattern. Extrahepatic immunohistochemical analysis revealed positive cells in the glandular acini and duct epithelial cells of the salivary gland and intrasarcoplasmic immunolabelling of random diaphragmatic myofibers. A possible role of both salivary gland and diaphragmatic muscle on local Hp production could be postulated based on the present immunohistochemical study, which supports the concept that other cells besides hepatocytes may have the potential to produce Hp in the pig.

Loss of poly(ADP-ribose) polymerase-2 leads to rapid development of spontaneous T-cell lymphomas in p53-deficient mice

Poly(ADP-ribose) polymerase-2 (Parp-2) belongs to a family of enzymes that catalyse poly(ADP-ribosyl)ation of proteins. Parp-2 deficiency in mice (Parp-2(-/-)) results in reduced thymic cellularity associated with increased apoptosis in thymocytes, defining Parp-2 as an important mediator of T-cell survival during thymopoiesis. To determine whether there is a link between Parp-2 and the p53 DNA-damage-dependent apoptotic response, we have generated Parp-2/p53-double-null mutant mice. We found that p53(-/-) backgrounds completely restored the survival and development of Parp-2(-/-) thymocytes. However, Parp-2-deficient thymocytes accumulated high levels of DNA double-strand breaks (DSB), independently of the p53 status, in line with a function of Parp-2 as a caretaker promoting genomic stability during thymocytes development. Although Parp-2(-/-) mice do not have spontaneous tumours, Parp-2 deficiency accelerated spontaneous tumour development in p53-null mice, mainly T-cell lymphomas. These data suggest a synergistic interaction between Parp-2 and p53 in tumour suppression through the role of Parp-2 in DNA-damage response and genome integrity surveillance, and point to the potential importance of examining human tumours for the status of both genes.

Fluorescence in situ hybridization in diluted and flow cytometrically sorted boar spermatozoa using specific DNA direct probes labelled by nick translation

Successful evaluation of X- and Y-chromosome-bearing sperm separation technology using flow cytometry-cell sorter is of great importance. Fluorescence in situ hybridization (FISH), which allows for the detection of specific nucleic acid sequences on morphologically preserved spermatozoa, is an ideal method for quantitatively and qualitatively assessing the purity of sorted sperm samples. In this study specific pig DNA direct probes for small regions of chromosomes 1 and Y were used. Chromosome 1 was labelled in green and used as internal control to detect a lack of hybridization, whereas chromosome Y was labelled in red. Nick translation was used as the labelling method for the preparation of these probes. Spermatozoa, unsorted and sorted for high and low Y-chromosome purity from ejaculates of five boars, were fixed on slides and two-colour direct FISH was performed for chromosomes 1 and Y. About 500 non-sorted and 200 sorted spermatozoa per sample were scored. The proportion of Y-chromosome-bearing spermatozoa was determined by the presence of a red fluorescent signal on the sperm head and the proportion of X-chromosome-bearing spermatozoa was determined by subtraction. The efficiency of the hybridization procedure was established as near 98% on sorted and unsorted samples. The results of this study confirm that direct FISH using specific pig DNA probes labelled by nick translation provides a useful tool for laboratory validation of sperm separation by flow sorting technology. Moreover, the ease of nick translation and the quality of the fluorescent signal obtained using this method makes this procedure the most appropriate method for labelling pig DNA probes to be used for direct FISH on pig spermatozoa.

Immunopathology of an hDAF transgenic pig model liver xenotransplant into a primate

BACKGROUND

hDAF transgenic pigs do not display the inherent hyperacute rejection reactions of pig-to-primate xenotransplants. The purpose of this study was to determine the immunopathologic phenomena following an hDAF transgenic pig hepatic orthotopic xenotransplant into a baboon.

METHODS

Donor animals were unmodified pigs (n=4) and hDAF transgenic pigs (n=2). Recipient animals were baboons (Papio anubis). Liver biopsies were immunostained using monoclonal antibodies to C3, C5b-9, IgG, IgM, CD2, CD4, CD8, CD68, CD20, Bric 216, CD31, and fibrin, and polyclonal antibody to C4.

RESULTS

hDAF transgenic grafts showed IgG, IgM, and C4 endothelial deposits. However, no fibrin, C3, or C5b9 deposits were observed after reperfusion. hDAF xenografts displayed CD31 staining in the portal spaces, perilobular areas, and at hepatic sinuisoidal levels. The baboon that lived for 4 days displayed either CD4 or CD8 T-cells periportal infiltrate.

CONCLUSIONS

Future studies will seek to determine the physiologic role of CD31 hepatic sinusoidal expression in transgenic xenotransplants, and will also study the role of T-cell infiltrates in xenograft rejection.

Life-supporting human complement regulator decay accelerating factor transgenic pig liver xenograft maintains the metabolic function and coagulation in the nonhuman primate for up to 8 days

BACKGROUND

It is not known whether the pig liver is capable of functioning efficiently when transplanted into a primate, neither is there experience in transplanting a liver from a transgenic pigs expressing the human complement regulator human complement regulator decay accelerating factor (h-DAF) into a baboon. The objective of this study was to determine whether the porcine liver would support the metabolic functions of non-human primates and to establish the effect of hDAF expression in the prevention of hyperacute rejection of porcine livers transplanted into primates.

METHODS

Five orthotopic liver xenotransplants from pig to baboon were carried out: three from unmodified pigs and two using livers from h-DAF transgenic pigs.

FINDINGS

The three control animals transplanted with livers from unmodified pigs survived for less than 12 hr. Baboons transplanted with livers from h-DAF transgenic pigs survived for 4 and 8 days. Hyperacute rejection was not detected in the baboons transplanted with hDAF transgenic pig livers; however, it was demonstrated in the three transplants from unmodified pigs. Baboons transplanted with livers from h-DAF transgenic pigs were extubated at postoperative day 1 and were awake and able to eat and drink. In the recipients of hDAF transgenic pig livers the clotting parameters reached nearly normal levels at day 2 after transplantation and remained normal up to the end of the experiments. In these hDAF liver recipients, porcine fibrinogen was first detected in the baboon plasma 2 hr postreperfusion, and was present up to the end of the experiments. One animal was euthanized at day 8 after development of sepsis and coagulopathy, the other animal arrested at day 4, after an episode of vomiting and aspiration. The postmortem examination of the hDAF transgenic liver xenografts did not demonstrate rejection.

INTERPRETATION

The livers from h-DAF transgenic pigs did not undergo hyperacute rejection after orthotopic xenotransplantation in baboons. When HAR is abrogated, the porcine liver maintains sufficient coagulation and protein levels in the baboon up to 8 days after OLT.

Association of HLA-DR4-Dw15 (DRB1*0405) and DR10 with rheumatoid arthritis in a Spanish population

OBJECTIVE

To analyze the associations of HLA class II antigens with rheumatoid arthritis (RA) in a Spanish population.

METHODS

We used DNA oligotyping to determine DR types, DQA1 and DQB1 alleles, and DR4 variants in 70 unrelated seropositive RA patients and 189 healthy controls living in Spain.

RESULTS

A significantly higher frequency of DR4 was seen in RA patients compared with controls (relative risk [RR] = 2.40). The DR10 specificity correlated most strongly with disease susceptibility (RR = 3.84). A significant decrease in the frequency of DR7 was observed in the RA patients (RR = 0.48). DR4-Dw15 (DRB1*0405) was found to be the unique DR4 allele associated with RA (RR = 4.27, P < 0.05), whereas Dw4 (DRB1*0401) and Dw14 (DRB1*0404/0408) showed no association, and both Dw10 (DRB1*0402) and Dw13 (DRB1*0403/0407) were negative risk factors for the disease. Approximately one-third of the cases of RA could not be explained by the "shared epitope" hypothesis. Investigation of the DQ alleles associated with DR4 showed that the haplotype Dw15-DQ8 (DRB1*0405-DQB1*0302) was a susceptibility factor for RA (RR = 6.36, P < 0.05).

CONCLUSION

Our results suggest that HLA class II alleles involved in RA susceptibility can vary among different Caucasian populations.

A human monoclonal autoantibody to a nucleolar structure

Peripheral blood lymphocytes from a scleroderma patient (CDC) were isolated, transformed with Epstein-Barr virus and fused to the heteromyeloma SHM-D33. Supernatants from cultures were screened for autoantibody production against nucleoprotamine by ELISA. Positive wells were cloned by limiting dilution. After cloning, supernatants from two wells were positive for the nucleoprotamine assay. One named CDC-1 has been studied in our laboratory. CDC-1 recognized a nucleolar antigen by indirect immunofluorescence. By using an ELISA with purified recombinant antigens, CDC-1 reacted against Ro/SS-A, U1 (RNP) and Sm. By immunoblotting using a lysate of MOLT-4 cell line, CDC-1 was able to react against a structure of 60 kD. When the antigen recognized by CDC-1 was purified, SDS-PAGE under reducing conditions with purified antigen and subsequent silver staining of the gel allowed us to detect three bands at 60, 55 and 39 kD, respectively. A screening by ELISA with previously characterized antisera against our purified antigen demonstrated reactivity of the CDC-1 antigen with those antisera able to recognize Ro/SS-A.

Production of heterohybridomas secreting autoreactive and polyreactive human monoclonal antibodies

Peripheral blood lymphocytes from two polytransfused renal dialysis patients were transformed by Epstein-Barr virus, fused to a heteromyeloma and cloned. Eight human monoclonal antibodies from the resulting clones were tested for their binding to a variety of antigens by ELISA, indirect immunofluorescence and immunoblotting. Antigens tested included B-cell lines, T and B lymphocytes, red blood cells, chronic lymphocytic leukaemic B cells, IgG, ssDNA, dsDNA, histones, nucleoprotamine, sperm nuclei, thymus and spleen extracts, MOLT4 cell lysates, affinity purified autoantigens, tetanus toxoid, bacterial lipopolysaccharide, insulin, and a tissue section screen. These human monoclonal antibodies reacted with more than one antigen to varying degrees and were autoreactive and polyreactive. One of these heterohybridoma cell lines exhibited cytoplasmic staining with an anti-CD5 monoclonal. Our findings support the concept that in adult individuals a subset of B cells produce heterogeneous IgM antibodies which can bind to a variety of different autoantigens and also to foreign antigens. These monoclonals were different from the autoantibodies usually seen in renal dialysis patients in the sense that they were not lymphocytotoxic.

Cloning of human heterohybridoma cell lines using chronic lymphocytic leukemia B cells as a feeder layer

B cells from the peripheral blood of chronic lymphocytic leukemia patients were isolated by gradient density centrifugation and used without irradiation as a feeder layer in the cloning of human heterohybridoma cell lines by limiting dilution. Cloning efficiencies were high with all the cell lines tested. These feeder leukemia B cells could also be successfully used after having been stored in liquid nitrogen.