Effective virus-specific T-cell therapy for high-risk SARS-CoV-2 infections in hematopoietic stem cell transplant recipients: initial case studies and literature review

The COVID-19 pandemic has exacerbated mortality rates among immunocompromised patients, accentuating the need for novel, targeted therapies. Transplant recipients, with their inherent immune vulnerabilities, represent a subgroup at significantly heightened risk. Current conventional therapies often demonstrate limited effectiveness in these patients, calling for innovative treatment approaches. In immunocompromised transplant recipients, several viral infections have been successfully treated by adoptive transfer of virus-specific T-cells (VST). This paper details the successful application of SARS-CoV-2-specific memory T-cell therapy, produced by an interferon-γ cytokine capture system (CliniMACS® Prodigy device), in three stem cell transplant recipients diagnosed with COVID-19 (case 1: alpha variant, cases 2 and 3: delta variants). These patients exhibited persistent SARS-CoV-2 PCR positivity accompanied by bilateral pulmonary infiltrates and demonstrated only partial response to standard treatments. Remarkably, all three patients recovered and achieved viral clearance within 3 to 9 weeks post-VST treatment. Laboratory follow-up investigations identified an increase in SARS-CoV-2-specific T-cells in two of the cases. A robust anti-SARS-CoV-2 S (S1/S2) IgG serological response was also recorded, albeit with varying titers. The induction of memory T-cells within the CD4 + compartment was confirmed, and previously elevated interleukin-6 (IL-6) and IL-8 levels normalized post-VST therapy. The treatment was well tolerated with no observed adverse effects. While the need for specialized equipment and costs associated with VST therapy present potential challenges, the limited treatment options currently available for COVID-19 within the allogeneic stem cell transplant population, combined with the risk posed by emerging SARS-CoV-2 mutations, underscore the potential of VST therapy in future clinical practice. This therapeutic approach may be particularly beneficial for elderly patients with multiple comorbidities and weakened immune systems.

Importance of donor-specific antibodies in the long-term outcome of liver-transplanted children

Összefoglaló. Bevezetés: A gyermekkori májtranszplantációk hosszú távú kimenetelének javítása érdekében az immunológiai mechanizmusok kerültek a kutatások középpontjába. A donorspecifikus antitesteknek (DSA-k) fontos szerepük van a graft túlélésében a szervtranszplantációk után, a májtranszplantáció esetén azonban ez még vitatott. Célkitűzés: Tanulmányunk célja májtranszplantált gyermekeknél a DSA-k meghatározása, valamint a DSA-k jelenléte és a graft állapota közötti összefüggés vizsgálata volt. Módszer: A Semmelweis Egyetem I. Sz. Gyermekgyógyászati Klinikáján gondozott 54 májtranszplantált gyermek vérmintájából történt a humán leukocytaantigén (HLA) elleni antitestek meghatározása. Vizsgáltuk, hogy a laboratóriumi vérvizsgálat eredményei - szérumbilirubin (összes, direkt), alkalikus foszfatáz (ALP), transzaminázok, gamma-glutamil-transzferáz (GGT), immunglobulin-G (IgG) -, az aszpartát-aminotranszferáz/thrombocyta hányadosindex (APRI) és a 4 tényezőn alapuló fibrosisindex (FIB4) tekintetében van-e eltérés a DSA-pozitív, illetve a HLA-immunizált betegek esetén a nem immunizált csoporthoz képest. Eredmények: A vizsgált paraméterekben nem találtunk szignifikáns különbségeket a DSA-pozitív, a HLA-immunizált és a nem immunizált betegek csoportjai között. Következtetés: Bár a jelen vizsgálatban nem volt szignifikáns különbség a vizsgált paraméterek esetén, de ez a kis esetszámból is adódhat. A DSA-knak a graftfibrosis kialakulásában való szerepe tisztázására több páciens vizsgálata szükséges, ezért megkezdtük az összes páciensnél a DSA- és HLA- (donor, recipiens) meghatározást, valamint ennek a klinikai gyakorlatunkba való beépítését. Orv Hetil. 2021; 162(47): 1897-1901.

SUMMARY

INTRODUCTION

To improve the long-term survival of liver-transplanted children, immunological mechanisms became the main interest of researchers. Donor-specific antibodies (DSAs) play a significant role in graft survival after solid organ transplantation, although their role in liver transplantation is controversial.

OBJECTIVE

The aim of our study was to determine the presence of DSAs in liver-transplanted children and to examine their effect on graft's condition.

METHOD

The determination of anti-human leukocyte antigen (HLA) antibodies was performed using the blood samples of 54 liver-transplanted children. We analysed the difference between the results of the laboratory blood examination - serum bilirubin (all, direct), alkaline-phosphatase (ALP), transaminases, gamma-glutamyl transferase (GGT), immunoglobulin-G (IgG) -, aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 index (FIB4) according to DSA and HLA immunization.

RESULTS

We did not find any significant difference in the examined parameters regarding DSA and HLA immunization.

CONCLUSION

Although this study was not able to provide significant difference in the examined parameters, this can be explained with the low number of cases. To clarify the significance of DSA in graft fibrosis, we need a larger dataset. We started regular DSA and HLA (donor and recipient) determination during follow-up in liver-transplanted children. Orv Hetil. 2021; 162(47): 1897-1901.

Management of antibody-mediated rejection after kidney transplantation in our clinical practice

Összefoglaló. Bevezetés: Az antitest közvetítette kilökődés a graftvesztés gyakori oka a vesetranszplantáltak körében. Célkitűzés: Célul tűztük ki, hogy ismertetjük a centrumunkban biopsziával igazolt humorális kilökődéssel rendelkező betegeknek a kezelésre (standard kezelés: plazmaferézis, immunglobulin, rituximab) adott válaszát, valamint hogy vizsgáljuk a proteinuria grafttúlélésre kifejtett hatását és azt, hogy ezt a DSA-tól függetlenül teszi-e. Vizsgáltuk az eGFR-, a DSA-MFI-értéknek az antirejekciós terápia hatására bekövetkező változásait is. Módszer: 85 beteg retrospektív analízisét végeztük el. A szövettani elemzésben a Banff-klasszifikációt vettük alapul. A csoportok összehasonlításához kategorikus változók esetén a Fisher-féle egzakt próbát, folyamatos változók esetén a Kruskal-Wallis-próbát használtuk. Eredmények: A biopsziával igazolt humorális rejekciós csoportba (ABMR-csoport) 19, a DSA-pozitív csoportba 14, a DSA-negatív csoportba 52 beteget választottunk be. A DSA-érték az ABMR-csoportban 61,16%-kal csökkent, a DSA-pozitív csoportban 42,86%-kal redukálódott (Fisher-féle egzakt: p = 0,1). Az ABMR-csoportban 9 betegnek a jelentős, 4-nek a nephroticus mértékű proteinuriája csökkenthető volt (az ABMR-csoport 68%-a). A legjobb grafttúlélés a legalacsonyabb fehérjeürítésnél adódott. Az antirejekciós terápiát követően készült biopsziákban: a glomerulitis, az interstitialis gyulladás, az arteritis mértéke csökkent az antihumorális kezelés hatására, azonban krónikus elváltozások jelentek meg. Következtetés: Az ABMR-csoportban az antirejekciós terápiát követően a fehérjeürítés monitorizálása javasolt, hiszen becsülhető vele a grafttúlélés. Orv Hetil. 2021; 162(26): 1029-1037.

SUMMARY

INTRODUCTION

Antibody-mediated rejection is a common cause of graft loss among kidney transplant recipients.

OBJECTIVE

We aimed to describe the response of patients with biopsy-proven humoral rejection to treatment (standard treatment: plasmapheresis, immunoglobulin, rituximab) in our center. We also analyzed the effect of proteinuria on graft survival and whether this effect is independent of donor-specific antibodies (DSAs). Changes of eGFR and level of DSA following rejection treatment were examined.

METHOD

In this study, laboratory data of 85 patients were analysed. Histological analysis was based on the Banff classification. Fisher's exact test was used for statistical analysis, and Kruskal-Wallis test was used to compare patient groups per variable.

RESULTS

Data from 85 patients were processed retrospectively. 19 patients were selected for the biopsy-confirmed humoral rejection group (ABMR group), 14 for the DSA-positive group, and 52 for the DSA-negative group. DSA titer decreased by 61.16% in the ABMR group after treatment and by 42.86% in the DSA-positive group (Fisher's exact test: p = 0.1). In the ABMR group, significant nephrotic proteinuria in 4 patients and severe proteinuria in 9 patients were reduced (68% of ABMR group). The patients with the lowest protein excretion had the best graft survival. In biopsies performed after antirejection therapy, the extent of glomerulitis, interstitial inflammation, arteritis decreased with antihumoral treatment, but chronic lesions appeared.

CONCLUSION

Following treatment of biopsy-proven ABMR, reduction of proteinuria predicts graft survival and should be monitored as an important factor-predicting prognosis. Orv Hetil. 2021; 162(26): 1029-1037.

The First 5 Years of the Newest Eurotransplant Member State: Hungarian Results of International Organ Exchange From 2014 to 2018

INTRODUCTION

Hungary joined Eurotransplant International (ET) to improve the chance of transplantation for Hungarian patients and patient outcomes, including access and graft and patient survival. After 5 years of full membership, the evaluation of numbers and quality indicators is possible.

METHOD

A comparison was made between 5 years prior to a preliminary cooperation agreement (2007-2011) and 5 years after full ET membership (2014-2018). During the 2 study periods, we analyzed numbers and circumstances of deceased organ donors, multiorgan donors, donated organs, and transplantations in Hungary and development of waiting lists along with international organ exchanges.

RESULT

The number of actual organ donors increased by 22.09% (729 vs 890), an additional 823 organ removals represents an increase of 42.71% (1927 vs 2750). There were 46.51% more transplants managed in the selected periods (1561 vs 2287). The number of new patients on the waiting list increased (2305 vs 3247; 40.87%). The mean kidney mismatch number decreased from 3.21 to 2.96.

CONCLUSION

Joining ET has been an effective and efficient in terms of increasing access to organs and the lives of patients on the Hungarian waiting list posttransplant. It is also a benefit for patients with special needs because the number of organ transplants is greater than the increased number of donors.

Antitestmediált rejekció: kihívás a veseátültetett betegek kezelésében

Abstract:

Antibody-mediated rejection (ABMR) is one of the factors affecting the long-term graft survival after kidney transplantation (KT). Two kidney transplant centres (University of Debrecen and University of Pécs) followed up their data of cadaveric KTs that had been performed between 2013 and 2017, and reviewed the literature. There were 454 KTs in the mentioned period, 18 cases (4%) were recognised as ABMRs. Biopsy has been performed in all cases. 22% were primary, and 78% retransplanted patients. The average age was 51.2 ± 6 years. ABMR occurred 15.4 ± 22.1 months after KT. Histology showed C4d positivity in 39% of the cases. The treatment was steroid bolus + intravenous immunoglobulin (IVIG) + plasma exchange (PE) in 16 cases, rituximab was additionally given in 5 cases. 47.4% of the patients are alive with a functioning graft, four (21%) died, and 31% of the patients had a graft loss due to ABMR. ABMR is a dangerous complication after KT. Diagnostic criteria has been unclear for years. Gold standard is the histology, however, accelerated ABMR may occur even in C4d negative cases. The exposed group includes young, retransplanted patients, having a preformed donor-specific antibody (DSA), and receiving a graft from an EC donor. The occurrence of de novo DSA and the kinetics of mean fluorescence intensity (MFI) of existing ones can be a signal for the risk of an ABMR. The effectiveness of rituximab is not proven, there is a lack of long-term controlled trials for new drugs. Our results of over 40% recovery is an extensively good result. Orv Hetil. 2018; 159(46): 1913–1929.

Concentration and Subclass Distribution of Anti-ADAMTS13 IgG Autoantibodies in Different Stages of Acquired Idiopathic Thrombotic Thrombocytopenic Purpura

Background

The acquired form of idiopathic thrombotic thrombocytopenic purpura (TTP) is an autoimmune disease, in which the underlying deficiency of the ADAMTS13 protease is caused by autoantibodies, predominantly of the IgG isotype. Certain HLA-DR-DQ haplotypes were associated with the risk of developing TTP.

Objectives

To investigate the development of the ADAMTS13-specific antibody response during the course of the disease, we analyzed the concentration, subclass distribution, and inhibitory potential of anti-ADAMTS13 IgG autoantibodies in samples of TTP patients drawn during the first acute phase, in remission, and during relapse. Additionally, we compared the anti-ADAMTS13 IgG levels between patients carrying and not carrying risk and protective HLA-DR-DQ haplotypes.

Patients and Methods

We determined the anti-ADAMTS13 IgG concentration and subclass distribution in 101 antibody-positive samples of 81 acquired TTP patients by ELISA methods. The presence and semi-quantitative amount of anti-ADAMTS13 inhibitors were determined in 97 of 100 deficient samples, and the specific inhibitory potential of anti-ADAMTS13 autoantibodies was determined in 49 selected samples, by mixing ADAMTS13-activity assays. HLA-DR-DQ typing and haplotype prediction were performed in 70 of the above patients.

Results

We found that IgG1 and IgG4 were the predominant subclasses, present in almost all samples. While IgG1 was the dominant subclass in almost half of the samples taken during the first acute episode, IgG4 was dominant in all samples taken during or following a relapse. The inhibitory potential of the samples correlated with levels of the IgG4 subclass. Anti-ADAMTS13 antibodies of IgG4-dominant samples had higher specific inhibitory potentials than IgG1-dominant samples, independently of disease stage. Interestingly, we found that patients carrying the protective DR7-DQ2 and DR13-DQ6 haplotypes had higher anti-ADAMTS13 IgG levels.

Conclusion

Our results indicate that IgG4 becomes the dominant subtype at some point of the disease course, apparently before the first relapse, parallel to the increase in inhibitory potential of the anti-ADAMTS13 autoantibodies. Furthermore, we found an association between the genetic background and the antibody response in TTP.

Identification of a novel HLA-B allele, HLA-B*08:177, in a Hungarian patient and her HLA identical sibling

The newly detected HLA-B*08:177 differs from HLA-B*08:01:01:01 by 1 single nucleotide substitution at position 365 of exon 3.

The role of human leukocyte antigen DRB1-DQB1 haplotypes in the susceptibility to acquired idiopathic thrombotic thrombocytopenic purpura

The acquired form of idiopathic thrombotic thrombocytopenic purpura (TTP) is an autoimmune disease, in which the underlying ADAMTS13-deficiency is caused by inhibitory autoantibodies against the protease. Human leukocyte antigens (HLA), responsible for antigen presentation, play an important role in the development of antibodies. The loci coding HLA DR and DQ molecules are inherited in linkage as haplotypes. The c.1858C>T polymorphism of the PTPN22 gene, which codes a protein tyrosine phosphatase important in lymphocyte activation, predisposes to a number of autoimmune diseases. We determined the HLA-DRB1-DQB1 haplotypes and the PTPN22 c.1858C>T genotypes in 75 patients with acquired idiopathic TTP and in healthy controls, in order to assess the role of these genetic factors and their interactions in the susceptibility to TTP. We found that the carrier frequencies of the DRB1^∗11-DQB1^∗03 and DRB1^∗15-DQB1^∗06 haplotypes were higher, while those of the DRB1^∗07-DQB1^∗02 and DRB1^∗13-DQB1^∗06 haplotypes were lower in TTP patients. There was no difference in the overall frequency of the PTPN22 c.1858T allele between TTP patients and controls. In conclusion, we identified four HLA-DRB1-DQB1 haplotypes associated with an increased (DRB1^∗11-DQB1^∗03 and DRB1^∗15-DQB1^∗06) or a decreased (DRB1^∗07-DQB1^∗02 and DRB1^∗13-DQB1^∗06) susceptibility to acquired idiopathic TTP.

Lipoprotein Lipase as a Prognostic Marker in Chronic Lymphocytic Leukemia

The marked clinical heterogeneity of CLL makes early prognosis assessment important. Lipoprotein lipase (LPL) has been shown to confer adverse prognosis in CLL, recent data indicating it might also contribute to CLL cell survival and metabolism. We determined LPL mRNA expression in unselected peripheral blood of 84 CLL patients by RT PCR. Results were correlated with other prognostic markers and outcome. 30/84 (40 %) of cases were LPL positive based on the cutoff established by ROC analysis. In LPL positive patients significantly shorter median survival (136 vs 258 months, p < 0.0001) and time to first treatment intervals (36 vs 144 months, p < 0.002) were documented. LPL values correlated with male gender, higher stages, more treatment requirement, CD38 positivity and unmutated IgVH genes. Among cases with 13q deletion, LPL positivity identified a subcohort with poor outcome (median survival 108 months vs NR, p < 0.0001). In multivariate analysis, cytogenetic aberrations and LPL had significant impact on survival. Our results confirm that LPL is a strong predictor of outcome in CLL, able to improve prognostic accuracy in good risk cytogenetic subgroups. The relationship between its prognostic and functional role in CLL needs to be explored further.

Peritubular capillary basement membrane multilayering in early and advanced transplant glomerulopathy: quantitative parameters and diagnostic aspects

The ultrastructural quantitative aspects of peritubular capillary basement membrane multilayering (PTCBML) were examined in 57 kidney transplant biopsies with transplant glomerulopathy (TG). The measurements included three cutoffs [permissive: 1 PTC with 5 basement membrane (BM) layers, intermediate: 3 PTCs with 5 layers or 1 PTC with 7 layers, strict: 1 PTC with 7 layers and 2 PTCs with 5 layers] and the mean number of BM layers (PTC_circ). Two groups were assigned, namely patients with mild TG (Banff cg1a and cg1b) and those with moderate-to-severe TG (cg2 and cg3). Their respective clinical, serological, and morphological characteristics were then compared. The clinical data revealed that mild TG corresponded to early chronic antibody-mediated rejection (cABMR), while moderate-to-severe TG corresponded to the advanced stage of the disease. The permissive threshold displayed the lowest specificity (73 %) and the highest sensitivity (83 %) for moderate-to-severe TG, and its corresponding PTC_circ value was 3 layers. In contrast, the strict threshold-adopted by the Banff 2013 classification-displayed a specificity and sensitivity of 93 and 52 %, respectively, and the corresponding PTC_circ was 4 layers. In mild TG, 26 % of the cases met the permissive cutoff and 6 % the strict cutoff. Mild TG was associated with a lower PTC_circ (2.6 layers vs 4.5 layers in moderate-to-severe TG; p < 0.0001). Amongst the various criteria, the permissive criterion was associated most frequently with mild TG, and had prognostic relevance. Because of this, we propose its usage as a marker of early cABMR-induced PTCBML if non-alloimmune causes of PTCBML can be ruled out.

Low occurrence of the HLA-C*04:09N allele in a large Hungarian cohort

The presence of null alleles may affect the outcome of stem cell transplantation. HLA-C*04:09N was defined as 'common' with a frequency of 2-5/1000 in Caucasians, and its presence is routinely tested as part of haplotypes HLA-A*02:01/A*23:01-B*44:03-DRB1*07:01-DQB1*02:01. We aimed to investigate HLA-C*04:09N in a representative Hungarian cohort. HLA-typing data of 7345 unrelated persons were analyzed. The presence of HLA-C*04:09N was excluded in 157 chromosomes with either serology typing or with an allele-specific polymerase chain reaction for HLA-C*04:09N. HLA-C*04:09N was identified in a single chromosome with HLA-A*02, B*44, C*04, DRB1*07 resulting in a HLA-C*04:09N allele frequency of 0.0068% (1/14,690). This is approximately a 10- to 40-fold lower frequency compared with the previous data. Our results emphasize the need of precise local population-specific HLA-data, allowing appropriate modifications of local HLA-typing protocols.

Decrease in cold ischemic times as a result of protocol changes of urgent immunogenetic testing during cadaveric kidney transplantation in Hungary

BACKGROUND

Based on national ethics committee permission, the procedure of urgent immunogenetics testing prior to cadaveric kidney transplantation was changed in Hungary from January 1, 2011 allowing HLA typing of the donor and prospective crossmatching using peripheral blood samples from the donor prior to the definitive declaration of brain death. The aim of the current study was to compare key indicators of transplantation primarily cold ischemic time [CIT], between time periods with outcomes.

METHODS

The following indicators were systematically collected prospectively and retrospectively for each deceased heart-beating donor transplantation between January 1, 2010 and October 31, 2010 (n = 114) versus January 1, 2011 and October 31, 2011 (n = 91): CIT for the first and second kidney; laboratory turnaround times (TAT), and time for final preparation of the selected recipient.

RESULTS

As a result of the new procedure, the CIT for the first kidney decreased from 16.5 ± 3.5 to 12.4 ± 3.2 hours (P < .001). Similarly, for the second kidney the parameters were a 19.8 ± 3.4 versus 16.0 ± 3.8 hours (P < .001). As a consequence of more hands-on time in the laboratory, the TAT increased from 5.6 ± 0.8 hours to 7.2 ± 1.1 hours (TAT1) followed by an additional 4.2 ± 1.0 hours (TAT2). We also compared the times necessary for preparation of immunologically suitable recipients for transplantation, namely, 9.5 ± 2.3 hours in the earlier system, increasing to 15.5 ± 4.3 hours during the new procedure.

CONCLUSION

As a consequence of the procedural change, the CIT parameter decreased significantly for both kidneys, which may have contributed to improved short-term outcomes of transplantation. The time available for final preparation of selected recipients was increased allowing improvements in CIT.

Frequencies of four ATP-binding cassette transporter G8 polymorphisms in patients with ischemic vascular diseases

ATP-binding cassette transporter G8 (ABCG8) was found to participate in plant sterol and cholesterol (CHOL) transport; however, the potential associations of ABCG8 genetic variants and ischemic vascular diseases are largely unknown. Determinations of allele frequencies of four common ABCG8 polymorphisms (D19H, Y54C, T400K, and A632V) were carried out in 241 unrelated patients with ischemic stroke, 148 patients with coronary heart disease, and 191 blood donors (controls). Allele frequencies of the investigated polymorphisms in patient groups showed no significant differences compared with controls. There was a tendency toward reduced 54YY-genotype frequency among male patients with stroke. On stratification by age at disease onset, male patients with stroke under the age of 50 (n = 62) showed significantly reduced 54YY-frequency compared with male controls (n = 92; 24.2% vs. 41.3%; odds ratio: 0.45 [95% confidence intervals: 0.22-0.93]; p = 0.038). No such associations were found among women. In healthy controls, CHOL levels of individuals with the 54YY genotype (n = 71; median: 4.51 mM, 25th-75th percentiles: 4.19-5.43) were significantly reduced compared with 54YC and 54CC individuals combined (n = 120; median: 4.95 mM, 25th-75th percentiles: 4.42-5.88, p = 0.009). Further, we identified a new ABCG8-variant, T401S, in a control subject. In conclusion, ABCG8 54YY-genotype may be a potential protecting factor against ischemic stroke in young men and may influence plasma CHOL levels.

Role of the activating mutation Val617Phe of Janus kinase 2 gene in myeloproliferative diseases and significance of its detection

The Val617Phe point mutation of Janus kinase 2 gene is believed to participate in the pathogenesis of myeloproliferative syndrome characterised by the clonal alteration of hematopoetic stem cells. According to current results, the frequency of Val617Phe activating mutation is around 80% in polycythaemia vera, 35% in essential thrombocythaemia, and 50% in chronic idiopathic myelofibrosis. The diagnoses of polycythaemia vera, essential thrombocythaemia and idiopathic myelofibrosis were so far based on the exclusion of secondary factors as well as bone marrow biopsy histology. The goal of the present work was to establish simple molecular genetic techniques for the routine testing of Janus kinase 2 gene Val617Phe mutation, and to compare the clinical phenotypes of Val617Phe mutation positive and negative myeloproliferative syndromes. We employed the allele specific polymerase chain technique for detection of Val617Phe mutation in 252 patients with myeloproliferative syndrome. We measured Val617Phe frequency as 85,4% (117/137) in polycytaemia vera, 56,6% (56/99) in essential thrombocythaemia, and 87,5% (14/16) in idiopathic myelofibrosis. We found significantly elevated hemoglobin levels and white blood cell counts (measured at the time of diagnosis) in Val617Phe-positive polycythaemia vera and essential thrombocythaemia patient groups compared to Val617Phe-negative patients. However, the frequencies of splenomegaly and other complications (thrombosis, bleeding, transformation to acute leukemia) were not significantly different between the mutation-positive and negative groups. In conclusion, the non-invasive mutation analysis of the Janus kinase 2 Val617Phe is suitable for routine laboratory application and helps the differential diagnosis of myeloproliferative syndrome. Althought the exact role of Val617Phe mutation testing has not yet been identified on the basis of a broad professional consensus, the testing is suggested in cases of erythrocytoses and thrombocytoses of unknown origin.

First and second line imatinib treatment in chronic myelogenous leukemia patients expressing rare e1a2 or e19a2 BCR–ABL transcripts

During the formation of the Philadelphia (Ph) chromosome, in the majority of chronic myelogenous leukemia (CML) patients, the chromosome 22 breakpoint is located in the major breakpoint cluster region of the BCR gene (M-bcr). Minor and micro breakpoint cluster regions (m-bcr with e1a2 transcript and micro-bcr with e19a2 transcript) are rarely affected and have been suggested to be associated with peculiar CML phenotypes. Despite the different clinical characteristics, it is currently not established, whether different therapeutic options are preferably recommended for the treatment of e1a2 or e19a2 CML. Here we report two patients with e1a2 and one patient with e19a2 translocations, treated with different approaches including imatinib. First and second line imatinib treatments induced haematologic response in all of the three patients, and major cytogenetic response in one patient with e1a2, as well as in the patient with e19a2 CML. However, relapse occurred in the patient with e19a2 CML, possibly caused by the presence of additional chromosomal abnormalities such as an extra Ph chromosome, and loss of chromosome Y. Stem cell transplantation (SCT) therapy caused complete haematologic response with molecular remission; however, the patient died of infectious complication. We conclude that in patients with rare BCR-ABL variants, the effectiveness of imatininb treatment may be influenced by the CML stage besides the actual molecular type of the rare transcript. However, this conclusion cannot be generalized to larger patient groups with rare BCR-ABL variants for which further studies may be needed.

Decreased frequencies of ABCA1 polymorphisms R219K and V771M in Hungarian patients with cerebrovascular and cardiovascular diseases

BACKGROUND AND PURPOSE

Genetic polymorphisms in ABC transporter A1 (ABCA1) may alter the regulation of plasma high-density lipoprotein (HDL), promoting or protecting from vascular diseases.

METHODS

We investigated 244 unrelated, consecutively enrolled patients with ischemic stroke, 150 patients with coronary heart disease (CHD) and 193 blood donors for allele frequencies (AFs) of three common ABCA1 polymorphisms (R219K, V771M and I883M).

RESULTS

Compared to controls (30.8 +/- 4.7 and 4.9 +/- 2.2%, respectively), decreased AFs were found in both patient groups for R219K and V771M (28.7 +/- 4.1 and 3.1 +/- 1.6% in stroke, and 25.7 +/- 5.0%; 1.3 +/- 1.3% in CHD patients, respectively). In a subset of stroke patients younger than 50, both variants occurred in significantly lower frequencies (22.4 +/- 5.5 and 1.8 +/- 1.7%, respectively). Similarly, among CHD patients younger than 60, AFs of R219K and V771M (22.6 +/- 7.5 and 0 +/- 1.6%, respectively) were decreased. V771M was almost exclusively (35/36) found in individuals carrying the R219K allele.

CONCLUSIONS

Our data confirm earlier observations that ABCA1 R219K and V771M polymorphisms may be associated with a protective role against CHD and extend those to another important pathologic condition, namely stroke.

Asymmetric PCR increases efficiency of melting peak analysis on the LightCycler

OBJECTIVES

To systematically analyze the effects of asymmetric PCR on LightCycler melting analyses of four different allelic-discrimination systems and to reduce an inconsistent non-specific melting peak observed during factor V Leiden genotyping.

DESIGN AND METHODS

PCR amplifications and melting analyses were carried out with various oligonucleotide concentrations and ratios. To monitor the efficiency, calculated peak area values were compared after melting analyses.

RESULTS

Peak area values increased by a mean of 11.2-fold (range: 6 to 17) in case of an amplification primer ratio of 1:6.7 asymmetric PCR compared to symmetric primer conditions in four different SNP-genotyping systems. Using a complementary hybridization probe set for factor V Leiden genotyping, a converse amplification primer ratio was necessary for similar results.

CONCLUSIONS

Asymmetric PCR resulting in the formation of higher amounts of target strands significantly increases the efficiency of LightCycler allelic-discrimination.