Value of allohaemagglutinins in the diagnosis of a polysaccharide antibody deficiency

Polysaccharide antibody deficiency is characterized by a poor or absent antibody response after vaccination with an unconjugated pneumococcal polysaccharide vaccine. Allohaemagglutinins (AHA) are antibodies to A or B polysaccharide antigens on the red blood cells, and are often used as an additional or alternative measure to assess the polysaccharide antibody response. However, few studies have been conducted to establish the clinical significance of AHA. To investigate the value of AHA to diagnose a polysaccharide antibody deficiency, pneumococcal polysaccharide antibody titres and AHA were studied retrospectively in 180 subjects in whom both tests had been performed. Receiver operating characteristic curves for AHA versus the pneumococcal vaccine response as a marker for the anti-polysaccharide immune response revealed an area under the curve between 0·5 and 0·573. Sensitivity and specificity of AHA to detect a polysaccharide antibody deficiency, as diagnosed by vaccination response, were low (calculated for cut-off 1/4-1/32). In subjects with only low pneumococcal antibody response, the prevalence of bronchiectasis was significantly higher than in subjects with only low AHA (45·5 and 1·3%, respectively) or normal pneumococcal antibody response and AHA (2·4%). A logistic regression model showed that low pneumococcal antibody response but not AHA was associated with bronchiectasis (odds ratio 46·2). The results of this study do not support the routine use of AHA to assess the polysaccharide antibody response in patients with suspected immunodeficiency, but more studies are warranted to clarify the subject further.

The phenotype and genotype of rheumatoid arthritis in the Democratic Republic of Congo

Introduction

Little is known about rheumatoid arthritis in the black, particularly in Congolese, populations. Our objective was to describe the phenotype and genotype of rheumatoid arthritis (RA) in Congolese.

Methods

All consecutive rheumatoid arthritis (RA) patients attending Kinshasa University Hospital in a three-year time period were included. Demographics, clinical features and tobacco consumption were noted. Disease Activity Score (DAS)-28 based on the erythrocyte sedimentation rate (ESR), Health Assessment Questionnaire (HAQ), anti-citrullinated peptide antibodies (CCP) antibodies and rheumatoid factor (RF) were determined. Radiographs were scored according to Sharp-van der Heijde. On a subset of patients and controls HLA-DRB1 typing was performed.

Results

A total of 114 females and 14 males aged 51.2 ± 14.9 were included. Mean duration of symptoms was four years. Moderate tobacco consumption was reported in a minority of patients. DAS-28 at first visit was >5.1 and HAQ ≥0.5 in all patients. X-rays showed joint erosions and/or joint space narrowing, mostly of a moderate grade in 55.8% of patients. Anti-CCP and/or RF were present in 48.6% of patients with available data (n = 72) and in 3.0% of controls (n = 67). Radiographic changes and nodules were more frequent in RF or anti-CCP positive patients. One copy of the shared epitope was found in 13 patients (35.1%) and 3 controls (12.5%). Two copies were found in one patient (2.7%) and in one control (4.2%).

Conclusion

Congolese patients with RA consult long after disease onset. Despite this delay, the majority presents without major damage and is RF, anti-CCP and SE negative. We put forward the hypothesis that besides different environmental factors there is probably also a particular genetic risk profile in Congolese patients, different from the HLA-DRB1 shared epitope.

Persistent polyclonal B-cell lymphocytosis

We present a case of persistent polyclonal B-cell lymphocytosis (PPBL). This syndrome is characterized by a persistent lymphocytosis with circulating atypical binucleated lymphocytes. The patient had serological evidence of a previous EBV infection, had raised polyclonal serum IgM levels and was a heavy smoker. No malignancy was detected.

Evaluation of anti-human leukocyte antigen allo-immunization in pediatric cadaveric kidney transplantation

Forty-eight pediatric cadaveric renal transplantations, performed between May 1986 and February 1997, were retrospectively screened, pre- and post-transplant, for antibodies to human leukocyte antigen (anti-HLA) using complement-dependent cytotoxicity (CDC) assay and enzyme immunoassay (EIA). The correlation between anti-HLA immunization and graft outcome was investigated. The combined analysis of CDC and EIA enabled the differentiation between complement-fixing and non-complement-fixing, anti-HLA class I and anti-HLA class II antibodies. The median post-transplant follow-up for all patients with a functioning graft was 86 months (range 10-138 months). In the whole population, 16 grafts were lost: six following a non-immunologic complication; and 10 as a result of rejection. Of these 10 grafts lost, eight were in patients with pre- and/or post-transplant donor antigen specific (DAS) anti-HLA class I or class I + II antibodies; and two were in patients with DAS anti-HLA class II antibodies only. Three of these grafts were lost in patients with weak pre-existing DAS anti-HLA class I antibodies. Immunological graft loss appeared at a median post-transplant time of 38 months (range 2-68 months). All patients without DAS anti-HLA antibodies had a good graft outcome. The presence of pre- and post-transplant DAS anti-HLA antibodies, especially if directed against HLA class I, were associated with a poor graft outcome. A systematic search for, and identification of, anti-HLA antibodies should therefore be part of a pretransplant evaluation to allow the identification of 'unacceptable' donor HLA antigens, following which the impact of the HLA-cross-match on graft outcome will improve. Screening for DAS anti-HLA antibodies post-transplant could be helpful for detecting patients with an increased risk for graft loss following rejection episodes.

Anti-hepatitis G E2 antibody detection and its relation to serum HGV-RNA in patients with clotting disorders: high prevalence of HGV infection and spontaneous remission

In a previous study, we have determined the prevalence of serum HGV-RNA in patients with congenital clotting disorders. Twenty-six (15%) of 175 patients investigated were serum HGV-RNA positive. In addition, HGV-RNA was detectable in peripheral blood mononuclear cells (PBMC) in ten percent of the cases, three of these patients were serum HGV-RNA negative. In the present study, we have determined the prevalence of anti-HGV-E2 antibodies in the same patient population. Anti-HGV-E2 as determined by ELISA was detected in 45 patients (25.7%). Forty of these patients were serum HGV-RNA negative. Ninety-two percent of the 26 HGV viremic patients and all but one patient (44 patients) with detectable anti-HGV-E2 had coinfection with the hepatitis C virus (HCV). Of these coinfected patients, 62.5% of HGV viremic patients and 53% of anti-HGV-E2 positive patients showed elevated serum ALT levels. Anti-HGV-E2 seroconversion is thus not associated with HCV infection. Two patients who were solely infected with HGV had normal serum ALT levels. In a retrospective longitudinal study, we have observed in 15 patients that serum HGV-RNA persisted during one to 19 years of follow-up, while anti-HGV-E2 was repeatedly negative. Five additional patients who were anti-HGV-E2 positive with concomitant detectable HGV-RNA (4 patients in serum and 1 patient in PBMC) became HGV-RNA negative during follow-up, ranging from 1 to 8 years after the first detection of anti-HGV-E2 antibodies. Two patients had lost anti-HGV-E2 antibodies 3 to 6 years after the seroconversion without the re-appearance of serum HGV-RNA. From these findings, it is clear that the prevalence rate of HGV infection in patients with clotting disorders as determined by PCR assay for HGV-RNA and anti-HGV-E2 by ELISA is actually higher than the prevalence of HGV viremia. Although HGV viremia may persist for longer than 19 years, most of the patients infected with HGV may clear the viremia spontaneously. The clearance of viremia is usually associated with seroconversion to anti-HGV-E2. In addition, anti-HGV-E2 may be lost during years of follow-up without the reappearance of the HGV-RNA. Although HGV infection does not seem to influence the fate of HCV infection and does not induce increased levels of serum ALT, the clinical significance of long-term infection remains to be established.

High prevalence of hepatitis G virus infection compared with hepatitis C virus infection in patients undergoing chronic hemodialysis

A recently discovered non-A-E hepatitis virus has been designated as hepatitis G virus (HGV) and identified as a new member of the Flaviviridae family. Infection by this virus is thought to be associated with blood-borne hepatitis and usually in the presence of hepatitis C or hepatitis B virus (HBV) infection. In this study, the presence of HGV-RNA in serum or plasma and the prevalence of antibodies against an HGV envelope protein (E2) were investigated in patients undergoing chronic hemodialysis using a sensitive reverse-transcriptase polymerase chain reaction and an enzyme-linked immunosorbent assay, respectively. HGV-RNA was detected in 19 of 112 patients investigated (17%) and anti-E2 antibodies were detected in 15 of 106 patients studied (14.2%). With the exception of two patients, the appearance of anti-E2 is associated with the clearance of serum HGV-RNA. The total prevalence of current (HGV-RNA positivity) and/or past (anti-E2 positivity) HGV infection in this patient population is thus 28.6% (32 of 112 patients were positive for serum HGV-RNA and/or anti-E2 antibodies). In apparently healthy blood donors, serum HGV-RNA was detected in four of 358 individuals (1.12%) and anti-E2 was not detected in 50 individuals investigated. From the 19 patients with serum HGV-RNA positivity, nine were coinfected with other hepatitis viruses (seven with HBV; one with HBV, hepatitis C virus [HCV], and hepatitis D virus; and one with HBV and cytomegalovirus). Thirteen of 15 patients with anti-E2 positivity (10 were positive for only anti-E2 and three were also positive for anti-HBc) had no detectable HGV-RNA. In two patients, both HGV-RNA and anti-E2 antibodies were concomitantly present (both patients were coinfected with HCV or HBV). Of the HGV-infected patients, only three who were coinfected with HBV showed elevated serum alanine aminotransferase levels. The serum HCV-RNA and/or anti-HCV were detected in five (4.5%) of 112 patients. From these findings, we conclude that there is a high prevalence of HGV infection (28.6%) compared with HCV (4.5%) in patients undergoing hemodialysis in our hospital. However, approximately 50% of patients had spontaneously lost the viremia and developed anti-HGV-E2 antibodies. We confirm that HGV infection alone is not associated with elevated serum transaminases, and the appearance of anti-HGV-E2 is usually accompanied with clearance of serum HGV-RNA. In contrast to the results of our previous study, the majority of patients infected with HGV are not coinfected with HCV, indicating that HGV is capable of independent transmission. It is likely that there is a preferential HGV acquisition in the hemodialysis unit. The clinical significance of long-term infection with HGV remains to be established.

A single course of remission reinduction chemotherapy for acute myelogenous leukemia relapsing after allogeneic bone marrow transplantation is complicated by graft-versus-host disease and followed by sustained complete remission

Graft-versus-host disease (GVHD) remains a major immunological complication after allogeneic bone marrow transplantation (allo-BMT), but also favors development of the beneficial graft-versus-leukemia (GVL) effect. A patient with AML-M4 (inv (16)) is described, who was given non-myeloablative remission reinduction therapy for leukemic relapse (inv (16), trisomy 8) diagnosed on day 184 after HLA-compatible sibling BMT. On day 236, ie about 6 weeks after completion of this course, a clinical syndrome suggestive of acute GVHD grade 3 had developed. Skin biopsy confirmed the clinical diagnosis of GVHD, with a compatible liver biopsy. Transfusion-associated GVHD was ruled out by analysis of short tandem repeat (STR) alleles in the skin biopsy, revealing alleles from donor and recipient but not from third party origin. Cyclosporin A (CsA) therapy, which had been tapered between days 150 and 175, was resumed, resulting in a favorable response and gradual transition to limited chronic GVHD. The patient has since remained in complete remission with an excellent performance status for more than 40 months, without further chemotherapy. Thus this biopsy proven case of GVHD was induced by marrow donor lymphocytes more than 200 days after transplantation and apparently triggered by remission reinduction chemotherapy. The case indicates that intensive non-myeloablative chemotherapy can cure AML relapsing after allo-BMT. The therapeutic effect in this case probably involved a direct pharmacological suppression of the leukemic clone followed by a GVL effect initiated by donor-derived alloreactive T lymphocytes.

An EIA method on single donor solubilized HLA antigens for the identification of anti-HLA antibodies

An enzyme immunoassay (EIA) method based on solubilized human leucocyte antigens (HLA) derived from single donor platelets is described. The EIA results on these solubilized single donor HLA antigens (SDszHLA) correlated well with the complement dependent cytotoxicity (CDC) results on the lymphocytes of the same donors and also with the panel reactivity (PRA) in CDC. A concordancy rate of 78% was found for individual HLA specificities. The EIA+/CDC- ('false positive') discrepancies were more pronounced than EIA-/CDC+ ('false negative') discrepancies and varied for the different donors. To confirm discrepancies, our method was compared with a commercial PRA-STAT EIA method (based on secreted soluble HLA antigens). The same discrepancies between CDC and PRA-STAT EIA were found and are probably due to the higher and different sensitivity (e.g. non complement fixing antibodies) of EIA methods. A SDszHLA EIA method allows the identification of HLA specificities of HLA-antisera. The possibility of using individual and selected donors for the production of SDszHLA allows the directed search for well defined HLA specificities in order to confirm anti-HLA specificities found in other anti-HLA screening methods. An individualized HLA panel can be established with the support of blood banks that have HLA typed blood and platelet donors.

HLA typing in a large family with multiple cases of different autoimmune diseases

OBJECTIVE

Because of the concurrence, in members of one family, of different autoimmune disorders [rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis (PS), and inflammatory bowel disease (IBD)], we investigated the genotypes of each member and compared the results with current knowledge of genetic inheritance of rheumatic and other autoimmune diseases.

METHODS

Sera and peripheral blood lymphocytes of 16 family members were collected for HLA typing and investigation.

RESULTS

All patients with RA were DR4 positive ad 4 of 5 showed the maternal A2B51DR4 haplotype. Two of 3 siblings with the genotype HLA-A2/3, B8/35, DR2/3 had SLE. Patients with IBD and psoriasis shared the haplotype HLA-A3, B35 CW4 DR2.

CONCLUSION

The results show that the important role of patients, sex and confirm the association between HLA haplotype and RA or SLE. They support the hypothesis that autoimmunity is a mendelian dominant trait, and that secondary genes, including these of the major histocompatibility complex, confer phenotypic specificity.

A single center evaluation of the Collaborative Transplant Study (CTS) DNA project

Historical HLA class II serological typing results of transplantations performed in "The Leuven Collaborative Group for Transplantation" were subjected to retrospective Restriction Fragment Length Polymorfism (RFLP) DNA control typing by the Collaborative Transplant Study (CTS) DNA project using Polymerase Chain Reaction (PCR)-based DNA methods. We re-evaluated the serology/ RFLP-discrepant CTS DNA data for our local patients transplanted during a historical period (January 1988 until May 1992) before any class II DNA typing was performed in our tissue typing laboratory. These retyping results confirm both the CTS data for patient typing and the Eurotransplant data for donor typing. A confirmed high discrepancy rate of 19.0% (after exclusion of 2.2% transcription errors) was found in the patient population. A low discrepancy rate of 6.8% (after exclusion of 2.2% transcription errors) for the donor population is concordant with the Eurotransplant donor data. Only 4 of the 588 individuals were found to be incorrectly typed by the RFLP method; all involving the specificities DRB1*1102. This indicates that RFLP typing, as performed by the CTS DNA project, can be considered a valid, retrospective DNA typing system for the accurate interpretation of class II matching in organ transplantation. A second conclusion to be drawn from this study is the need for prospective DNA typing for kidney transplant recipients, as the discrepancy rate in this cohort is high. Our results suggest that with good quality serological HLA-DR typing, prospective donor DNA typing is not urgently needed.

Treatment of patients with myelodysplastic syndromes with allogeneic bone marrow transplantation from genotypically HLA-identical sibling and alternative donors

Between December 1981 and March 1994, 24 patients with a myelodysplastic syndrome (MDS) underwent allogeneic bone marrow transplantation (BMT) for RA with trilineage dysplasia (n = 4), CMML (n = 1), RAEB (n = 4), RAEBt (n = 9) and AML following MDS (n = 6). Fifteen patients (two RAEB, seven RAEBt and six sAML) received chemotherapy before BMT resulting in complete remission in 10 patients (six RAEBt and four sAML) at the time of BMT. Sixteen marrow donors were genotypically HLA-identical siblings. Remaining donors were other family members (five) or unrelated donors (three). The status of the underlying disease at the time of conditioning was the major factor determining long-term survival. The disease-freed survival of RA patients and patients presenting with RAEB, RAEBt and AML but transplanted in complete remission, was respectively 50 and 60%. On the contrary, none of the nine high-risk MDS patients transplanted with persistent disease, survived. Outcome after transplantation with alternative donors was inferior with one long-term survivor, mainly related to the high incidence of severe acute GVHD and its accompanying infectious complications. Six patients relapsed resulting in an actuarial probability of relapse of 28%. Twelve patients died of transplant-related complications leading to a non-relapse mortality at 5 years of 50%. At present eight patients are alive and disease-free 20 to 132 months post-transplantation resulting in an actuarial 5-year disease-free survival of 40.7%. Our results suggest that allogeneic bone marrow transplantation is a feasible treatment option for patients with MDS. However, improvement in GVHD prophylaxis and supportive care to reduce transplant-treated mortality and improved relapse prevention are imperative.

Prospective HLA-DR matching in penetrating keratoplasty

This prospective study examines whether HLA-DR matching has a beneficial effect on corneal graft survival of high risk patients. Until now, 196 donors have been typed in order to provide 20 patients with a matching graft. The results, though preliminary, are very encouraging.

Association of particular HLA class II alleles, haplotypes and genotypes with susceptibility to IDDM in the Belgian population

Using a highly discriminatory DNA typing technique, based on the polymerase chain reaction and reverse dot blot hybridization, more refined results were obtained on the association of particular HLA class II alleles, haplotypes and genotypes with insulin-dependent diabetes mellitus in the Belgian population. The previously reported predisposing effect for the DRB1*0301 encoded DR3 serologic specificity was confirmed and could be assigned to the DRB3*0200 encoded DR52b serologic specificity. A second high risk haplotype, DRB1*0401-DQB1*0302 encoding the DR4-DQ8 serologic specificity, accounted for increased susceptibility both in the total insulin-dependent diabetic population and among DR4-positive patients. Moreover, we found that these DR4 associated DRB1 and DQB1 alleles act as independent risk factors. A possible role for the DPB1 locus can be rejected since the observed predisposing effect for DPB1*0202 probably occurred due to linkage disequilibrium of this allele with DRB1*0301. Particular extended haplotypes accounted for the decreased relative risk observed for the DR2, DR11 and DR13 serologic specificities. The highest relative risk was observed for those DQA1/DQB1 genotypes, allowing for the formation of 4SS (DQ alpha Arg52+/DQ beta Asp57-) heterodimers.

Rapid DNA typing of class II HLA antigens using the polymerase chain reaction and reverse dot blot hybridization

A nonisotopic oligotyping method using reverse dot blot hybridization was developed for HLA class II DQA1, DQB1, DPB1, DRB1, DRB3, DRB4, DRB5 alleles. The polymorphic second exon of the different genes was amplified by the polymerase chain reaction (PCR). For each gene the amplified DNA was hybridized at stringent conditions to membrane-bound sequence-specific oligonucleotides (SSOs) and visualization of positive signals was done by chemiluminescence. A combination of 11, 18, 23 and 31 SSOs was designed to identify 9/13 DQA1, 16/17 DQB1, 23/24 DPB1 and 50/55 DRB1, 4 DRB3, 1 DRB4, 3/4 DRB5 alleles respectively. For the DRB1 locus, an additional DRB1*04 group-specific PCR was developed to make discrimination between the DR4 alleles possible in different heterozygous combinations. The procedure described here provides rapid and nonisotopic genotyping of heterozygous samples from a variety of sources and can be applied for tissue typing, disease susceptibility studies and forensic medicine.

The role of intensive remission induction and consolidation therapy in patients with acute myeloid leukaemia

Sixty-one patients with AML, 59 adults and two children, were treated with intensive remission induction and consolidation therapy. The median age was 36 years. Forty-four (72%) patients entered complete remission (CR); 11 patients received a bone marrow transplantation. The median survival of complete remitters was 26.5 months; the probability of remaining in CR at respectively 1 and 2 years was 75% and 62%. The only factor significantly correlated with the outcome of remission induction, survival and duration of CR was age. Patients less than 30 years fared significantly better than those 30 years or older; no difference in outcome was observed between patients aged 30-50 and those over 50 years. In patients less than 30 years the CR rate was 95%; 75% of them were still alive at 2 years and only one (5%) has relapsed. In contrast, in patients 30 years or older the CR rate was 60% and the median survival only 11.5 months, 50% of the complete remitters in this age group have relapsed. Morbidity from intensive consolidation therapy was considerable; more than 50% of consolidation courses were complicated by high fever, needing urgent admission; only four (3%) courses had a fatal event. It is concluded that intensive consolidation therapy may be considered as a major advance in the treatment of younger patients with AML, while its role in older individuals remains questionable. A possible explanation for the completely different outcome in younger and older patients with AML is discussed.