Definition of gene content for nine common group B haplotypes of the Caucasoid population: KIR haplotypes contain between seven and eleven KIR genes

Abstract Although outcomes after allogeneic hematopoietic cell transplantation (alloHCT) for AML have improved, this has mainly been attributed to a reduction in transplant-related mortality rather than reduced leukemia relapse. NK cell alloreactivity is regulated by inhibitory and activating signals mediated through cell-surface receptors including the killer immunoglobulin-like receptors (KIRs). Group A and B KIR haplotypes have distinct centromeric (Cen) and telomeric (Tel) gene-content motifs and donor Cen group B KIR haplotypes have been reported to be associated with decreased relapse and improved survival in AML patients undergoing unrelated donor alloHCT. We hypothesized that donor KIR genotype may also be predictive of outcomes after matched related donor (MRD) alloHCT. We evaluated 93 AML patients in CR1/CR2 who underwent T-cell replete alloHCT using HLA- matched related donors at our institution from 1/2000-3/2013. Sixty-six had myeloablative conditioning (MAC) that that was busulfan/cyclophosphamide-based and 27 had reduced-intensity conditioning (RIC) with fludarabine/total body irradiation or busulfan/fludarabine. Donors were KIR genotyped to assign haplotypes A/A vs. B/X and the distinctive Cen and Tel gene-content motifs of group A and B KIR haplotypes according to the presence or absence of one or more B haplotype-defining KIR genes. KIR B–content score for each KIR genotype was defined as the number of Cen and Tel gene-content motifs containing B haplotype–defining genes (range, 0-4). As compared to those with haplotypes B/X (n=40; B content scores of 1-4) those with haplotype A/A (n=25; B content score of 0) undergoing MAC had significantly lower 100-day, 6-, 12- and 24-month non-relapse mortality (NRM) (8% vs. 0%, 13% vs. 0%, 15% vs. 0%, 25% vs. 0%, respectively, Figure 1) which was confirmed on multivariable analysis (HR 9.19, p=0.03). There were no differences between these groups regarding patient and transplant-related characteristics, or for acute or chronic GVHD, relapse, or survival. The causes of death in the group with haplotypes B/X were most commonly attributed to infection and then GVHD. However, within the group with B/X haplotypes, the B motif content score (1-4) was not associated with significant differences in NRM (HR 0.79, p=0.56). No difference in outcomes was observed for those undergoing RIC. The number of donor activating KIR genes (2SD1, 2DS2, 2DS3, 2DS4, 2DS5, and 3DS1) was then assessed. As compared to those with 3-6 activating KIR genes (n=20) those with 0-2 (n=41) undergoing MAC had significantly lower 100-day, 6-, 12- and 24-month non-relapse mortality (NRM) (15% vs. 0%, 15% vs. 5%, 15% vs. 5%, 29% vs. 8%, respectively, Figure 2) which was confirmed on multivariable analysis (HR 4.07, p=0.01). There were no differences in other post-transplant outcomes when comparing these groups or when considering those undergoing RIC. An increase of 1 donor activating KIR also was highly associated with NRM (HR 1.37, p=0.008). Overall, these results suggest that in the MRD MAC alloHCT setting donor KIR genotype may be predictive of increased NRM risk, particularly for those with B/X haplotypes and greater numbers donor activating KIRs. No comparable effects were observed in the RIC setting. Future strategies to further enhance immune reconstitution post-transplant may be appropriate to pursue for these higher risk patients. These results may have potential implications to improve donor selection for those AML patients with multiple HLA-matched related donors and need to be validated in larger cohorts. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

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Bruton tyrosine kinase inhibitors (BTKi) therapies in chronic lymphocytic leukemia (CLL): Review of multiple trials data for incidence of lymphocytosis and designation of partial response with lymphocytosis (PRL).

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.e19502 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. e19502-e19502

Author(s):

Jayant Narang ◽

Christiana Caplan ◽

Katarina Ludajic ◽

Sambit Ray ◽

Surabhi Bajpai ◽

...

Keyword(s):

Partial Response ◽

Kinase Inhibitors ◽

Absolute Lymphocyte Count ◽

Lymphocytic Leukemia ◽

Additional Parameter ◽

True Incidence ◽

Overall Response ◽

Group A ◽

Definition Of ◽

Group B

e19502 Background: In trials with BTKi, lymphocytosis alone may not be a sign of progression but rather treatment related redistribution of lymphocytes from tissues into the peripheral blood (Cheson et al 2012). This observation was later incorporated in iwCLL 2018 criteria. However, no clear details were provided on how to assess lymphocytosis along with other parameters to derive an overall timepoint response (OTR) in a clinical trial setting. While PRL is a response category used to assess lymphocytosis in many clinical trials, it has not been defined in iwCLL 2018. Furthermore, iwCLL 2018 defines Absolute Lymphocyte Count (ALC) progression (PD) as an increase of ALC ≥ 50% compared to baseline whereas conventionally progression is defined in comparison to nadir, which may lead to under reporting of ALC PD. Methods: Data from multiple (8) phase II/III CLL trials with BTKi (frontline and relapsed/refractory setting), were retrospectively analyzed. Subjects with a post baseline (post-BL) timepoint (TP) were analyzed for the incidence of ALC PD and an OTR designation of PRL, PD and other non-PD assessments (Stable Disease (SD), Non-PD and Unknown (UNK)). Results: We identified 1976 subjects with a total of 17134 post BL TPs. There were 1182 TPs (6%) with ALC PD. Out of these TPs with ALC PD, 497 TPs had OTR of PRL (42% TPs with ALC PD), 365 TPs (31%) were assessed as non-PD and 320 (27%) TPs were assessed as PD. 104 TPs (33%) of subjects with OTR of PD had at least one additional parameter driving PD. Thus, ALC PD is a common occurrence with BTKi and in line with the Cheson 2012 guidance, ALC PD alone should not be considered as overall progression. We propose that initial ALC PD with BTKi should not be considered a sign of progression but rather a treatment effect and should be assessed as PRL. However, PRL should only be assessed if Partial Response (PR) is achieved in at least 2 other involved iwCLL group A parameters (nodes, liver or spleen) and 1 group B parameter (hemoglobin or platelets). An initial decrease/normalization of the ALC compared to baseline with a subsequent progression compared to nadir, may be considered true progression in a setting of continued BTKi. If only one other group A parameter is involved and is PR with associated ALC PD, SD may be a more appropriate overall response than PRL. Conclusions: ALC PD and PRL are common in BTKi, but there is a need for standardization of the definition of ALC PD and its role in determination of OTR of PRL. We propose that ALC PD should be assessed by comparing ALC with nadir and not baseline. If PRL is assigned only when PR is met by other criteria along with ALC PD, PRL could be a part of determining Overall response rate (ORR) in protocols. Future prospective studies are needed to estimate the true incidence of ALC PD and its impact on ORR with BTKi as well as other agents which induce lymphocytosis.

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Definition of a bacterial virulence factor: sialylation of the group B streptococcal capsule.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.86.22.8983 ◽

1989 ◽

Vol 86 (22) ◽

pp. 8983-8987 ◽

Cited By ~ 128

Author(s):

M. R. Wessels ◽

C. E. Rubens ◽

V. J. Benedi ◽

D. L. Kasper

Keyword(s):

Virulence Factor ◽

Bacterial Virulence ◽

Bacterial Virulence Factor ◽

Definition Of ◽

Group B

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Selecting Haploidentical Transplant Donors for Deploying Optimal NK Cell Allotherapy.

Blood ◽

10.1182/blood.v114.22.511.511 ◽

2009 ◽

Vol 114 (22) ◽

pp. 511-511

Author(s):

Loredana Ruggeri ◽

Antonella Mancusi ◽

Marusca Capanni ◽

Teresa Aloisi ◽

Alessandra Carotti ◽

...

Keyword(s):

Hematopoietic Cell Transplantation ◽

Nk Cell ◽

Conflicts Of Interest ◽

Significant Variable ◽

Clinical Role ◽

Kir Genes ◽

Group A ◽

Group B ◽

Kir Gene

Abstract Abstract 511 Donor-versus-recipient NK cell alloreactivity has been established as a key therapeutic element in HLA haplotype mismatched hematopoietic transplants in adult AML (Ruggeri et al. Blood 1999; Science 2002; Blood 2007; Stern et al., Blood 2008) and paediatric ALL (Pende et al. Blood 2009). It is effected by donor NK cells which express inhibitory KIRs for self class I KIR ligands (HLA-C1, C2, Bw4). In KIR ligand mismatched recipients, they sense missing expression of donor KIR ligand(s) and mediate alloreactions. Recent studies have proposed refinements to this mechanism and have emphasized the role of donor activating KIR variants in the control of leukemia relapse after haploidentical (Pende et al. Blood 2008) and unrelated (Cooley et al. Blood 2009) hematopoietic cell transplantation. ∼25% of Caucasians are homozygous for A haplotypes which contain inhibitory KIR genes and the KIR2DS4 activating KIR (non-functional in 2/3 of individuals). 75% of Caucasians are either heterozygous or homozygous for B haplotypes which carry not only inhibitory KIRs but also various combinations of activating KIRs (KIR2DS1-2-3-5 and KIR3DS1). Our extensive functional assessments of donor NK clone repertoires from representative sets of A (homozygous) or B (homozygous and heterozygous) haplotype donors, involving functional analyses of >5,000 NK clones from 70 donors, revealed that frequencies of alloreactive NK cell clones did not differ significantly in A vs B haplotype donors, that NK alloreactive repertoires in B haplotype positive individuals were largely composed of clones which did not express activating KIR(s) and, finally, that activating KIR-negative clones killed as efficiently as the positive. In contrast, dramatic differences emerged when inflammatory cytokine production was assessed in alloreactive NK clones with possessed or did not possess activating KIR variants. Upon incubation with KIR ligand-mismatched LPS or Aspergillus or CMV antigen-treated DCs, NK clones expressing activating KIR receptors produced several-fold more IFN-gamma and TNF-alfa than NK clones not expressing activating KIRs. The clinical role of donor activating KIR genetics was evaluated in 86 haploidentical transplants for AML. 49 recipients were transplanted from NK alloreactive (KIR ligand-mismatched) donors (12 with group A KIR gene haplotypes vs 37 with B haplotypes) and 37 recipients from non-NK alloreactive (KIR ligand-matched) donors (8 with group A KIR gene haplotypes vs 29 with B haplotypes). The remarkable GvL effect of NK alloreactive transplants (Ruggeri et al. Blood 2007) was unaffected by donor A vs B KIR gene haplotypes. In contrast, in transplants from NK alloreactive donors, presence of group B haplotype KIR genes in the donors was associated with reduced incidence of TRM (largely infection-related) (B vs A haplotypes: 20% vs 67% TRM, p<0.01). In multivariate analyses it was the only significant variable predicting protection from TRM (RR: 0.24; 95% CI:0.14-0.42; p<0.01). When the number of activating KIR genes in the donor was taken into account, donors carrying ≥ 3 activating KIR genes provided significant protection from TRM and significantly better EFS compared with A haplotype donors (TRM: 12% vs 67%, p<0.003) (EFS: 71% vs 33%, p=0.02). In multivariate analysis, transplantation from alloreactive donors carrying ≥3 group B haplotype activating KIR genes was the only variable predicting protection from TRM (RR: 0.36; 95% CI: 0.25-0.54; p<0.01) and tended to improve EFS (RR: 0.64; 95% CI: 0.38-1.07; p<0.1). We conclude that NK alloreactive, KIR ligand-mismatched donors who possess activating KIRs may confer protection against infections through their enhanced NK cell cytokine secretion upon interaction with recipient pathogen-infected DCs. Disclosures: No relevant conflicts of interest to declare.

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Analyses of HLA-C–specific KIR repertoires in donors with group A and B haplotypes suggest a ligand-instructed model of NK cell receptor acquisition

Blood ◽

10.1182/blood-2010-03-273656 ◽

2011 ◽

Vol 117 (1) ◽

pp. 98-107 ◽

Cited By ~ 76

Author(s):

Kathrin Schönberg ◽

Martina Sribar ◽

Jürgen Enczmann ◽

Johannes C. Fischer ◽

Markus Uhrberg

Keyword(s):

Nk Cells ◽

Nk Cell ◽

Hla Class I ◽

Cell Receptor ◽

Suppressive Effect ◽

Class I ◽

Nk Cell Differentiation ◽

Group A ◽

Common Group ◽

Group B

Abstract To determine the influence of KIR and HLA class I polymorphism on human NK cell repertoires, 32 different clonotypes representing all possible combinations of 4 inhibitory KIR and NKG2A were analyzed by multicolor flow cytometry. In donors homozygous for the common group A KIR haplotype, a significant influence of HLA-C ligands was seen: KIR repertoires were dominated by clonotypes expressing a single KIR for the respective cognate ligand, either the C1-specific KIR2DL3 or C2-specific KIR2DL1. In contrast, in donors possessing the polymorphic group B haplotypes, a similar adaptation to cognate HLA-C was lacking. We suggest that this discrepancy is largely the result of a suppressive effect of the group B–specific KIR2DL2 on the frequency of KIR2DL1+ NK cells. In functional assays, KIR2DL2 not only recognized C1 but also C2 ligands, showing overlapping specificity with KIR2DL1. Moreover, using an NK cell differentiation assay we show sequential acquisition of KIR2DL2 before KIR2DL1 on developing NK cells. Together, these observations are compatible with a ligand-instructed model of NK cell education, in which recognition of HLA class I by an inhibitory receptor (KIR2DL2) suppresses subsequent expression of a second receptor (KIR2DL1) of related specificity. Importantly, the ligand-instructed model fits to the observed KIR repertoires in both broad KIR haplotype groups.

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Phenotypic and Genotypic Characterization ofMycobacterium africanum Isolates from West Africa

Journal of Clinical Microbiology ◽

10.1128/jcm.37.6.1921-1926.1999 ◽

1999 ◽

Vol 37 (6) ◽

pp. 1921-1926 ◽

Cited By ~ 38

Author(s):

Richard Frothingham ◽

Percy L. Strickland ◽

Gisela Bretzel ◽

Srinivas Ramaswamy ◽

James M. Musser ◽

...

Keyword(s):

Sierra Leone ◽

Tandem Repeats ◽

Drug Resistant ◽

Polymorphic Genes ◽

Intergenic Regions ◽

Group A ◽

Definition Of ◽

Group B ◽

Vntr Analysis ◽

Simple Definition

The Mycobacterium tuberculosis complex includesM. tuberculosis, M. bovis, M. africanum, and M. microti. Most clinical isolates areM. tuberculosis or M. bovis. These species can be distinguished by phenotypes and genotypes. However, there is no simple definition of M. africanum, and some authors question the validity of this species. We analyzed 17 human isolates from Sierra Leone, identified as M. africanum by biochemical and growth characteristics. We sequenced polymorphic genes and intergenic regions. We amplified DNA from six loci with variable numbers of tandem repeats (VNTRs) and determined the exact number of repeats at each locus in each strain. All M. africanumisolates had the ancestral CTG Leu at katG codon 463. Drug-resistant M. africanum isolates had katGand rpoB mutations similar to those found in drug-resistantM. bovis and M. tuberculosis. Fourteen Sierra Leone M. africanum isolates (designated group A) hadkatG codon 203 ACC Thr, also found in M. africanum T (the T indicates type strain) from Senegal. Group A isolates clustered with M. africanum T by VNTR analysis. Three M. africanum isolates (group B) had katG codon 203 ACT Thr, found in M. tuberculosis T, and clustered with M. tuberculosis T by VNTR analysis. Phenotypic identification of M. africanumyielded a heterogeneous collection of strains. Genotypic analyses identified a cluster (M. africanum group A) which includedM. africanum T and was distinct from the rest of the M. tuberculosis complex. Future studies ofM. africanum should include both phenotypic and genotypic analyses.

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372 ESOPHAGEAL BODY PERISTALSIS CORRELATES FOR DYSPHAGIA AND REGURGITATION: AN ASSESSMENT BASED ON BARIUM ESOPHAGRAM

Diseases of the Esophagus ◽

10.1093/dote/doaa087.89 ◽

2020 ◽

Vol 33 (Supplement_1) ◽

Author(s):

L Giulini ◽

D Razia ◽

S Mittal

Keyword(s):

Clinical Symptoms ◽

Objective Assessment ◽

Esophageal Peristalsis ◽

High Resolution Manometry ◽

Number Of Patients ◽

Barium Esophagram ◽

Group A ◽

The Mean ◽

Definition Of ◽

Group B

Abstract Because it offers real-time assessment, barium esophagram should be the modality of choice when studying esophageal peristalsis. However, no standard reporting method is available for BE results. Presently, peristaltic disorders are defined according to high-resolution manometry (HRM), but HRM findings do not correlate with clinical symptoms. The aim of this study was to stratify esophageal peristaltic function via standardized evaluation of BE, and to define the association between esophageal peristalsis and dysphagia and regurgitation. Methods After IRB approval, a prospectively maintained database was reviewed for patients who underwent both HRM and BE from 08/01/2016 to 12/31/2019. Patients with conditions associated with outflow impairment were excluded. BEs were re-examined in blinded fashion and assigned subjective scores (0, 1, or 2) for dilation grade (DG) and contractility grade (CG). Patients were categorized according to the sum of the DG and CG: Group A = 0, Group B = 1–2, and Group C = 3–4. Mean distal contractile integral (DCI), number of failed contractions on HRM, and number of patients with dysphagia/regurgitation in each group were analyzed and compared. Results In all, 124 patients were included. The mean DCI (mmHg*cm*s) was 2539.1 ± 1357.8 in Group A, 884.4 ± 916.9 in Group B, and 77.4 ± 192.3 in Group C (p < 0.001). The mean number of failed contractions were 0.7 ± 1.3, 3.4 ± 3.4, and 8.6 ± 3.2, respectively (p < 0.001). Table 1 shows the distribution of patients with dysphagia or regurgitation across groups. The proportion of patients with dysphagia in Group C was higher than in Groups A or B (OR 3.75, p = 0.02; and OR 2.58, p = 0.07, respectively). Similarly, Group C was significantly more often associated with regurgitation than in Groups A or B (OR 4.69, p = 0.009; and OR 4.42, p = 0.005). Conclusion The combined DG and CG allowed us to identify the patients with a grade of peristaltic disfunction that was significantly more associated with dysphagia or regurgitation (Group C). However, in order to achieve a clearer definition of the different peristaltic disfunction levels according to their propensity to cause dysphagia or regurgitation, a more objective assessment of both DG and CG should be provided; therefore, further studies are required.

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Transplant Donor KIR Genotype Influences the Rate of CMV Reactivation Following T-Replete Stem Cell Transplantation.

Blood ◽

10.1182/blood.v104.11.188.188 ◽

2004 ◽

Vol 104 (11) ◽

pp. 188-188 ◽

Cited By ~ 1

Author(s):

Mark Cook ◽

David C. Briggs ◽

Charles F. Craddock ◽

Premini Mahendra ◽

Donald Milligan ◽

...

Keyword(s):

Stem Cell ◽

T Cell ◽

Stem Cell Transplantation ◽

Cell Transplantation ◽

Myeloablative Conditioning ◽

Kir Genes ◽

Group A ◽

Group B ◽

Cmv Reactivation ◽

Haplotype A

Abstract Background CMV reactivation is the commonest viral complication following allogeneic stem cell transplantation (SCT) and is a direct consequence of immunodeficiency. Natural killer (NK) and T-cells are the primary effector populations that suppress CMV replication. Killer immunoglobulin-like receptors (KIRs) are expressed on the surface of NK cells and T-cell subsets. Inhibitory KIRs have specificity for defined alleles of class I HLA and deliver an inhibitory signal to the cell. Activating KIRs bind weakly to HLA molecules and their true ligands remain unknown. KIR genes are polymorphic. Two broad haplotypes exist which differ in the number of activatory KIR genes that they contain. Haplotype A has 1 activatory KIR gene whereas haplotype B contains additional activatory genes. Methods We studied 107 patients undergoing allogeneic SCT at 3 UK Institutions to evaluate the effect of activating KIRs on CMV reactivation. Two thirds received standard myeloablative conditioning with TBI/Cy or Bu/Cy. One third received non-myeloablative conditioning. Recipient/donor CMV sero-status was determined by ELISA. Reactivation was defined as two successive PCR assays detecting >400 copies/ml. KIR genotyping was performed by PCR-SSP. Results In CMV seropositive recipients, the CMV reactivation rate was 50% in transplants from sibling donors and 64% in transplants from unrelated or HLA non-identical donors. In sibling transplants where both donor and recipient were CMV seropositive and the donor was homozygous for KIR Haplotype A (group A) the CMV reactivation rate was 65% .In contrast if the donor possessed at least one KIR haplotype B (group B) the reactivation rate was reduced to 27.5% (p=0.014). The protective effect of group B donors was seen only in patients who received a myeloablative non-T-depleted transplant. Here, the reactivation rate was 70.6% (12 from 17) when transplanted from a group A donor compared with 23.8% (5 from 21) when transplanted from a group B donor (p=0.0039). If a group B donor was used no reactivation was seen after 41 days, whereas in transplants from group A donors the risk of reactivation continued until day 100 (figure 1,p=0.018). The donor KIR genotype did not influence CMV reactivation rates in patients who received T-depleted grafts from sibling, unrelated or haploidentical donors. Conclusion In T-cell replete sibling donor transplants the use of a donor with multiple activating KIRs significantly reduces the risk of CMV reactivation when both donor and recipient are CMV seropositive. This is the first direct evidence of activating KIRs exerting a controlling effect on CMV in humans.

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