Isodisomy of chromosome 6 in a newborn with methylmalonic acidemia and agenesis of pancreatic beta cells causing diabetes mellitus.

Isodisomy (ID) is a genetic anomaly defined as the inheritance of two copies of the same genetic material from one parent. ID in an offspring is a rare cause of recessive genetic diseases via inheritance of two copies of a mutated gene from one carrier parent. We studied a newborn female with a mut(o) of methylmalonic acidemia and complete absence of insulin-producing beta cells in otherwise normal-appearing pancreatic islets, causing insulin-dependent diabetes mellitus. The patient died 2 wk after birth. Serotyping of the HLA antigens, DNA typing of HLA-B and HLA class II loci, study of polymorphic DNA markers of chromosome 6, and cytogenetic analysis demonstrated paternal ID, involving at least a 25-centiMorgan portion of the chromosome pair that encompasses the MHC. ID probably caused methylmalonic acidemia by duplication of a mutated allele of the corresponding gene on the chromosome 6 inherited from the father. It is also very likely that ID was etiologically related to the agenesis of beta cells and consequent insulin-dependent diabetes mellitus in our patient. We thus speculate on the existence of a gene on chromosome 6 involved in beta cell differentiation.

Lack of association between HLA-DR antigens and sleep-onset REM periods in major depression.

Narcolepsy is the disease disclosing the strongest association with the HLA system. Almost 100% of cases are associated with HLA-DR2 antigen. Moreover, narcolepsy is often characterized by the occurrence of sleep-onset REM (SOREM) periods. SOREM has also been demonstrated in major depression. To further investigate the relationship between SOREM and HLA-DR2, HLA-DR and HLA-DQ antigens were assessed in 50 research diagnostic criteria (RDC) major depressed patients. Depressed patients were elected for HLA typing on the basis of the presence of at least one SOREM period (n = 29) or three REM latencies above 50 min (n = 21) during three consecutives EEG nights recording. No significant differences were observed in the frequency of HLA-DR or HLA-DQ antigens between patients and controls. These results demonstrate a lack of association between SOREM and HLA-DR2 in major depression, and also do not confirm the presence of an association between antigens encoded by the HLA region of the chromosome 6 and major depressive illness.

Optimal control of interferon-gamma and tumor necrosis factor-alpha by interleukin-10 produced in response to one HLA-DR mismatch during the primary mixed lymphocyte reaction.

Interleukin (IL)-10 is an immunosuppressive cytokine potentially involved in the control of the allogeneic response. Several studies failed to detect it in mixed lymphocyte reaction supernatants. However, experiments using IL-10-specific antibodies, revealing its inhibitory action on interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha, provided indirect evidence that endogenous IL-10 was produced. The aim of the present work is to elucidate the role of IL-10 during mixed lymphocyte reaction and to investigate the influence of HLA-DR antigens on its production and on the regulatory loop involving TNF-alpha and IFN-gamma. Using a highly sensitive ELISA, a significant (P < 0.0001) but low IL-10 release could be detected (33.7 +/- 3.6 pg/ml) in response to HLA-DR disparities. However, IL-10 release was not graded as 1 DR mismatch (MM)-induced maximal secretion (32.3 +/- 5.1 pg/ml). This contrasted with TNF-alpha and IFN-gamma productions, which significantly increased in 2 DR MM pairs. Addition to IL-10-specific antibodies resulted in higher enhancement of INF-gamma (235 +/- 38% vs. 122 +/- 39%, P = 0.02) and, to a lesser extent, TNF-alpha (147 +/- 56% vs. 112 +/- 20%, NS) in 1 compared with 2 DR MM pairs. We conclude that the 1 DR MM setting is associated with optimal IL-10 secretion and more efficient inhibition of IFN-gamma and TNF-alpha compared with the 2 DR MM configuration. Although promoting enhanced IFN-gamma and TNF-alpha release, introduction of an additional DR MM does not result in increased IL-10 production. These data indicating that the IL-10 regulatory feedback loop is more effective in 1 DR rather than complete DR incompatibility could have an impact on matching policies for planned transfusion.

Influence of donor-recipient HLA-DR mismatches and OKT3 prophylaxis on cadaver kidney graft survival.

Previous studies from our center have shown that donor-recipient HLA-DR mismatches (MM), characterized by the presence of the DR antigen in the donor but not in the recipient or vice versa, are associated with differential effects on graft survival (GS): some of them are beneficial (BEN) with results similar to those of HLA-DR identical or compatible pairs (85% 18 months GS) and some are detrimental (DET) (64% 18 months GS), whereas the other MM, neither BEN nor DET (neutral [NEU]) yield intermediate results (78% 18 months GS). The aim of the present study was to update the results at a longer follow-up time and to assess whether they are influenced or not by prophylactic administration of anti-CD3 mAb (OKT3). The analysis of 234 transplantations performed from 1980 to 1994 with only 1 HLA-DR MM confirmed the BEN effects of HLA-DR5 in either the donor or the recipient and the DET effects of HLA-DR1 or -DR2 in the donor and of HLA-DR2 or -DRW6 in the recipient. These effects were independent of those exerted by other, HLA-DR not related, prognostic factors. The transplants with 1 HLA-DR MM were then compared with those with zero HLA-DR MM (n = 378) and 4 groups were formed according to 2 levels of HLA-DR MM (zero or BEN MM vs. NEU or DET MM) and immunosuppression (with vs. without OKT3 prophylaxis). GS at 5 years was 63% in the group with either zero or BEN MM as compared with 41% in the group with either NEU or DET MM in the absence of OKT3 prophylaxis (P < 0.02); in comparison, with OKT3 prophylaxis, GS at 5 years was 73% in the group with either zero or BEN MM as compared with 58% in the group with either NEU or DET MM (P = 0.07). We conclude that the differential effects of HLA-DR MM on GS are still observed under OKT3 prophylaxis, that the effects of HLA-DR and immunosuppression on graft outcome are additive, and that OKT3 induction therapy is superior to therapy without OKT3. These observations could have important implications for the allocation policy and management of renal transplants.

Detection of blood chimerism after lung and heart-lung transplantation. The superiority of nested as compared with standard polymerase chain reaction amplification.

Migration of donor cells from the graft to various tissues of the recipient has been demonstrated after different types of solid organ transplants. Currently, the detection of donor cells in the recipient's tissues is most simply performed by polymerase chain reaction (PCR) amplification of a donor-specific gene. In the present study, we first determined in vitro the sensitivity of standard and nested PCR amplification with sequence-specific primers (PCR-SSP) of a donor-specific allele of the HLA-DRB1 gene and then used this technique to assess prospectively blood chimerism in two single-lung (SLT) and one heart-lung (HLT) transplant recipients. Standard PCR-SSP consisted in a single amplification round with sequence-specific primers for the donor-specific DRB1 allele. Nested PCR-SSP consisted in a first round of generic amplification of exon 2 of the DRB1 gene, followed by a second amplification round with primers specific for the donor allele. In vitro, nested PCR-SSP of the donor-specific allele was 1000-fold more sensitive than standard PCR-SSP and allowed the detection of 1 donor cell in 10(5) recipient cells. In vivo, standard PCR-SSP detected donor cells among the recipients' peripheral blood mononuclear cells (PBMCs) only during the first postoperative days, whereas nested PCR-SSP demonstrated their presence until the end of the first postoperative month in patients 1 and 2 and until 3 months after transplantation in patient 3. We conclude that donor cells can be detected in the peripheral blood of SLT and HLT recipients during the first postoperative months and that nested PCR-SSP amplification of a donor-specific HLA-DRB1 allele is much more sensitive than standard PCR-SSP to demonstrate such chimerism.

Tumor necrosis factor-alpha and interleukin-6 production induced by variations of DR4 polymorphism during the primary mixed lymphocyte reaction.

Serologically defined MHC class II differences provoke release of TNF-alpha and IL-6 during MLR. In order to assess the influence of micropolymorphism defined at the genomic level, we selected informative donors pairs within DR2 DR4 serologically defined unrelated subjects by combining those differing only by DR4 alleles, as assessed by PCR-SSOP (DRB1*0401 to 07). Two groups of MLR combinations were tested including DRB1-identical (group 1, n = 12) and one DRB1 difference (group 2, n = 16). Pairs of HLA-identical siblings (n = 4) and of unrelated subjects differing by two major DR incompatibilities detected by serology (n = 27) were used as controls. We further investigated whether DP and DQ differences contributed to the observed CK production. Comparison of group 2 with group 1 showed that one DRB1 difference had a marked influence on CK production at day 3 (TNF-alpha: 401.8 +/- 85 pg/ml vs. 128.7 +/- 34.5 pg/ml, P = 0.001; SI = 2.97 +/- 0.23 vs. 1.27 +/- 0.09, P < 0.0001; IL-6: 317.6 +/- 44.8 pg/ml vs. 108 +/- 13 pg/ml, P = 0.003; SI = 2.53 +/- 0.37 vs. 1.11 +/- 0.05, P < 0.0001). However, CK release in group 2 was significantly lower than that observed in subjects with two serologically defined DR differences (TNF-alpha: 515.1 +/- 61.4 pg/ml, P = 0.05; SI = 5.61 +/- 0.48, P < 0.0001; IL-6: 545.9 +/- 75.8 pg/ml, P = 0.03; SI = 4.75 +/- 0.58, P < 0.0004). Addition of LPS after one day of MLR resulted in discriminant production of CK in group 2 as compared with group 1. Neither DP nor DQ differences affected CK production. In conclusion, DR subtypic differences induce significant CK release during primary MLR. This in vitro study demonstrates the immunodominance of the DR system in eliciting strong inflammatory mediators release.

Lung rejection occurs in lung transplant recipients with blood chimerism.

BACKGROUND: It has been postulated that chimerism after transplantation might promote graft acceptance. In the present study, we prospectively assessed blood chimerism in 10 lung transplant recipients during the first posttransplant year and investigated whether chimerism was associated with an immunologically stable situation of the graft. METHODS: The recipients' peripheral blood mononuclear cells were obtained before transplantation and at various time points during the first postoperative year. Donor cells were detected using nested polymerase chain reaction amplification of a donor-specific HLA-DRB1 allele. Clinical graft acceptance was determined by the number of rejection episodes. RESULTS: The incidence of blood chimerism was high during the first 3 postoperative months and then decreased over time. All patients experienced at least one acute rejection episode, and three patients developed chronic rejection. CONCLUSION: We, thus, conclude that rejection of the lung allograft may occur in the presence of blood chimerism.

Interleukin 12 unmasks HLA class I differences during mixed lymphocyte reaction induced interferon gamma production.

We investigated the genetic control of IFN-gamma release during MLR and its relationship with TNF-alpha and IL-12. Blocking experiments demonstrated the IFN-gamma dependence of TNF-alpha production and the significant contribution of IL-12 to IFN-gamma secretion. We studied informative pairs allowing the evaluation of the relative importance of HLA class I and class II antigens. Maximal IFN-gamma secretion allowing discrimination between fully HLA different and identical subjects required 5 days. In class I different but DRB1 identical pairs, a moderate but discriminant IFN-gamma release was found. Exogenous IL-12 addition after 24 hours of preactivation by MLR resulted in a marked enhancement of IFN-gamma production at day 2. In pairs differing only by class I antigens, the discriminating capacity was significantly increased as compared to values obtained in absence of IL-12 at day 2 (p < 0.004) and at day 5 (p < 0.004). The crucial role of class I antigens on IFN-gamma release was further substantiated by the blocking action of the W6/32 mAb directed against a monomorphic epitope common to all HLA-A, -B, and -C antigens. We conclude that IFN-gamma production during MLR is under the control of class I antigens. Furthermore, exogenous IL-12 strongly amplifies their influence.

Alloactivation induced during mixed-lymphocyte reaction provokes release of tumor necrosis factor alpha and interleukin 6 by macrophages and primes them to lipopolysaccharides.

We tested various factors affecting the production of the CKs IL-6 and TNF-alpha during in vitro alloactivation induced by MLR. Different MLR combinations involving familial and unrelated pairs were evaluated. In family studies, MLRs involving pairs of HLA-identical siblings (n = 6) were characterized by IL-6 and TNF-alpha secretion comparable to the one of autologous controls, in marked contrast with HLA-different combinations (n = 6). These displayed a strong and early (day 3) release of both CKs. In combinations of unrelated individuals involving HLA-A, -B, -C-different but -DR, -DQ-identical pairs (n = 3), low CK release was observed. Addition of LPS (1 micrograms/ml) considerably increased production of IL-6 and TNF-alpha. Clear discrimination of MHC class II differences required a 24-hour preculture followed by addition of LPS for 4 hours, a time relationship compatible with a priming phenomenon due to alloactivation. We conclude that MHC class II alloactivation not only provokes IL-6 and TNF-alpha secretion, but also primes macrophages to LPS so that the production of these CKs is markedly increased and occurs much earlier after LPS addition.

Molecular characterization of a recombinant HLA-DR1/DR2 haplotype.

Serologic analysis of two families identified an HLA-DR haplotype in which DR1 and DR2 cosegregated. DNA-RFLP analysis of these families with an HLA-DRB probe revealed a pattern of hybridization suggestive of a recombination between DR1 and DR15. Following amplification, cloning, and nucleotide sequencing of HLA-DRB-gene second-exon DNA sequences, three DRB amplification products associated with the novel haplotype were identified: these corresponded to DRB1*0101, DR2 pseudogene, and DRB5*0101. Clones representing the DRB1*1501 and DR1 pseudogenes were not identified: oligonucleotide typing with DRB1*1501-specific probes confirmed the absence of this gene within the DR1/DR2 haplotype. We postulate that the DR1/DR2 haplotype represents a recombinant between those of DR1-Dw1 and DR15-Dw2, and that the crossing-over may have been between the DRB1*0101 gene and the DR2 pseudogene. This is further supported by DNA-RFLP analysis with HLA-DQB and DQA CDNA probes, which revealed conserved linkage genes between the DQB1*0501, DQA1*0101, and DRB1*0101 genes.

[Favourable effects of some HLA-DR disparities on kidney graft survival. Proposal for a new recipient selection policy]. / Effets favorables de certaines incompatibilités HLA-DR sur la survie de l'allogreffe rénale. Proposition en faveur d'une nouvelle politique de sélection des receveurs.

In a previous retrospective study conducted from 1980 to 1987 on 275 renal cadaveric transplants, we have shown that HLA-DR disparities between donor and recipient exerted differential effects on graft survival. Thus, the presence of DR4, DR5 and DR7 in the donor, or of DR5 in the recipient was associated with an excellent survival, whereas disparities due to the presence of DR1 and DR2 in the donor, or of DR2, DRw6 and DR7 in the recipient were detrimental for the graft. A prospective study on 158 renal cadaveric transplants performed from 1988 to 1990 yielded results that were similar to those of the retrospective study. Graft survival at 18 months was similar in recipients who had either the same DR antigens as those present in their donor or beneficial DR disparities only (83-90 percent), and significantly higher than in recipients with DR detrimental disparities only (62-65 percent). Graft survival in recipients with either mixed or neutral DR disparities occupied an intermediate position (77-78 percent). In conclusion, grafts with excellent outcome, similar to that observed in DR identical pairs, may be proposed to an ever increasing number of patients awaiting a renal transplant by adopting a selection policy based on the choice of beneficial DR disparities when a DR identical recipient is not available in the pool.

[Alloimmune neonatal thrombocytopenia]. / Les thrombocytopénies néonatales alloimmunes.

Neonatal alloimmune thrombocytopenia (NAIT) is due to fetomaternal incompatibility for platelet specific antigens, most frequently HPA-1a (PLA1) and HPA-5b (BRa). It occurs in approximately 1/2.000-1/5.000 births. The most serious complication of NAIT is intracranial hemorrhage. The risk of life-threatening hemorrhage must lead to prompt diagnosis and effective therapy. Improvements in antenatal diagnosis and in utero therapy facilitate appropriate management of pregnancy at risk for NAIT. We report our experience with the serological diagnosis of 14 NAIT cases using new performing techniques such as western blotting (WB) and MAIPA (monoclonal antibody specific immobilization of platelet antigens).

[Immunological selection of bone marrow donors]. / Sélection immunologique des donneurs de moelle osseuse.

In the last twenty years bone marrow transplantation has become the treatment of choice for many hematological malignancies and immunologic defects. The ideal donor is a perfectly HLA-identical family member. Given the limited proportion of patients who can benefit of such a donor, unrelated bone marrow donors are increasingly being used. The immunological methods of selection used for siblings have been shown to be inadequate for the new type of donors. New techniques of molecular biology detecting a new micropolymorphism have been developed. This paper discusses the techniques and interpretations of the immunological tests of selection.

[Immunotherapy of recurrent spontaneous miscarriages (idiopathic abortive disease): preliminary results]. / Immunothérapie des fausses couches spontanées à répétition (maladie abortive idiopathique): résultats préliminaires.

Recurrent spontaneous abortion (greater than or equal to 3 spontaneous miscarriages) represents an entity defined by negative criteria (absence of anatomical, hormonal, autoimmune and chromosomal abnormalities). The immune hypothesis is corroborated by the successes (greater than or equal to 80 %) of specific (paternal leucocytes) or non-specific (intravenous gammaglobulins) immunotherapeutic trials. Studies on the mechanisms of action of those two methods will afford information on the pathogenesis of this condition.

[The immunology-hematology-transfusion department]. / Le Service d'Immunologie-Hématologie-Transfusion.

New immunotherapies derived from biotechnology offer fascinating perspectives in different fields of medicine including anti-infectious vaccines, cancer, organ transplantation and autoimmune diseases. In this paper, we illustrate how the Department of Immunology can contribute to the development of these new treatments within a academic hospital such as the Erasme Hospital at the Université Libre de Bruxelles.

[Nutrition education or managing social communication for nutrition?]. / Education nutritionnelle ou gestion de la communication sociale en nutrition?

Seven years ago Hygie published an article on the limits of conventional nutrition education in urban Africa. Strategies and methods in communication for nutrition have since evolved, incorporating results of international research to develop innovative, highly participative approaches. In this article the authors provide an extensive analysis of the different methodologies used in nutrition education programmes, in particular the KAB, social marketing, and community participation models, indicating main areas where each method used separately has failed. Members of the African Nutritional Education Network (RENA) have studied the above mentioned approaches, modifying them or integrating certain elements to adopt a more effective approach, which they consider somewhat as the management of social communication for nutrition education. Needs assessments and programme planning are largely enhanced by a causal analysis component specific to nutrition education in a community setting which has been developed by the authors. Other classic elements of programme implementation such as community participation, diversity of methods and intervention, are then combined with a multi-level/multi-actor evaluation processes to produce what the authors esteem to be a more effective nutrition education programme. They conclude, however, with the warning that although behavioural modifications brought about by nutrition communication and education might be beneficial for public health, they could have different, possibly adverse effects on other aspects of society. Effective nutrition education must therefore be included in a more extensive field of health promotion by acting on the multiple factors which influence the nutrition and health state of vulnerable groups.

Multiple transfusions for sickle cell disease in the Democratic Republic of Congo: the importance of the hepatitis C virus.

BACKGROUND AND OBJECTIVES: Improvement of transfusion security in sub-Saharan countries requires the determination of priorities taking into account the specific context. PATIENTS AND METHODS: One hundred and forty patients with sickle cell disease (SCD) from one clinical centre for SCD in Kisangani, DRC were tested for HBsAg, anti-HIV antibodies, anti-HCV antibodies and for alloantibodies against red blood cells and human leucocyte antigens (HLA). RESULTS: Thirteen patients had not been transfused and were free of HBV, HIV or HCV infection. HBV, HIV and HCV infections were detected in 2/127 (1.6%), 1/127 (0.9%) and 10/127 (7.9%) transfused patients, respectively. All ten cases of HCV infection were associated with patients who had transfusions prior to the introduction of HCV testing in 2004 (P=0.043). Red blood cells and HLA alloantibodies were detected in 13/127 (10%) and 2/127 (1.6%), respectively. CONCLUSION: HCV testing should be a priority. The rhesus (Rh) phenotype, mainly the RhD antigen and the Kell antigen should be assessed in SCD patients. Further extended phenotyping and deleucocytation should not be considered as priorities.