ALBERT

Description: Background Telehealth (TH) was introduced as a promising tool to support integrated care for the management of chronic obstructive pulmonary disease (COPD). It aims at improving self-management and providing remote support for continuous disease management. However, it is often not clear how TH-supported services fit into existing pathways for COPD management. The objective of this study is to uncover where TH can successfully contribute to providing care for COPD patients exemplified in a Greek care pathway. The secondary objective is to identify what conditions need to be considered for successful implementation of TH services. Methods Building on a single case study, we used a two-phase approach to identify areas in a Greek COPD care pathway where care services that are recommended in clinical guidelines are currently not implemented (challenges) and areas that are not explicitly recommended in the guidelines but that would benefit from TH services (opportunities). In phase I, we used the care delivery value chain framework to identify the divergence between the clinical guidelines and the actual practice captured by a survey with COPD healthcare professionals. In phase II, we conducted in-depth interviews with the same healthcare professionals based on the discovered divergences. The responses were analyzed with respect to identified opportunities for TH and care pathway challenges. Results Our results reveal insights in two areas. First, several areas with challenges were identified: patient education, self-management, medication adherence, physical activity, and comorbidity management. TH opportunities were perceived as offering better bi-directional communication and a tool for reassuring patients. Second, considering the identified challenges and opportunities together with other case context details a set of conditions was extracted that should be fulfilled to implement TH successfully. Conclusions The results of this case study provide detailed insights into a care pathway for COPD in Greece. Addressing the identified challenges and opportunities in this pathway is crucial for adopting and implementing service innovations. Therefore, this study contributes to a better understanding of requirements for the successful implementation of integrated TH services in the field of COPD management. Consequently, it may encourage healthcare professionals to implement TH-supported services as part of routine COPD management.

Description: Immunoglobulin (IG) G-switched chronic lymphocytic leukemia (G-CLL) is highly enriched for 3 stereotyped CLL subsets, utilizing either the IGHV4-34 gene, namely mutated subsets #4 and #16, or the IGHV4-39 gene, namely unmutated subset #8. These subsets, collectively accounting for ~30% of all G-CLL, are not represented within the common IgM/D variant, thus prompting speculations about distinct ontogenetic origin and/or immune triggering, as well as raising questions regarding the timing of class-switch recombination (CSR) in relation to malignant transformation. Considering the above, we sought to investigate the potential existence of B cells expressing clonotypic mu transcripts within the bulk of IgG-switched CLL cells in cases assigned to the aforementioned subsets. Using high-throughput next-generation sequencing (NGS, MiSeq Illumina), we interrogated the IgM+ B-cell repertoire of CLL subset #4 (n=8), subset #16 (n=1) and subset #8 (n=2) for the presence of clonotypic mu transcripts. PCR amplicons were generated from cDNA using a set of IGHV4/IGHM primers. The paired-end Illumina protocol allowed sequencing of the complementarity determining region 3 (CDR3) twice/read, thus increasing the accuracy of results. For 3/8 subset #4 cases multiple blood samples of the same time point were analyzed as reproducibility controls. A purpose-built bioinformatics algorithm was developed for raw NGS data processing, which included: (i) quality filtering of reads; (ii) merging of paired-end reads via local alignment; (iii) preparation of filtered-in fasta sequences for submission to the IMGT/HighV-QUEST tool; and, (iv) IMGT/HighV-QUEST metadata mining for subset-specific B-cell receptor (BcR) IG rearrangements. Subset-specific CDR3 motifs were defined according to established criteria. Overall, 7,125,958 IGHV-IGHD-IGHJ-IGHC rearrangements (189,988-673,835/sample) were included in the search for stereotyped motifs, corresponding to 1,056,967 distinct clonotypes (i.e. BcR IG rearrangements with a particular IGHV gene and amino acid CDR3 sequence) (7,163-123,276/sample, median=76,109). Regarding subset #4, 7/8 cases exhibited mu transcripts of subset #4-specific IG rearrangements ("subset #4 M-clonotypes"); by definition, these rearrangements utilized the IGHV4-34/IGHJ6 genes and had identical CDR3 length (20 amino acids), however their CDR3 amino acid composition varied (2-75 distinct subset #4 M-clonotypes/sample, median=8). In 5/7 cases these subset #4 M-clonotypes were characterized by CDR3s that were identical and/or highly similar (≤2 amino acid differences, ≥ 90% identity) to the CDR3 of the IgG-switched CLL clone. The M-clonotypes expressing CDR3s identical to those of the IgG-switched CLL clone represented the most expanded subset #4 M-clonotype within the sample, while the less expanded, "satellite" clonotypes may represent subclones that were selected against due to lower affinity with the driving antigen. The possibility that these “satellite” clonotypes derive from PCR and/or sequencing error cannot be a priori excluded, however replicate sample analysis produced identical subset #4 M-clonotypes in all cases tested, thus raising confidence in the accuracy of the data. Analysis of the subset #16 case yielded similar results, i.e. 2 subset #16 M-clonotypes, one of which was identical to the IgG-switched clonotypic BcR IG. Both subset #8 cases also carried subset #8 M-clonotypes, yet only one case exhibited an M-clonotype with a CDR3 identical to that of the respective G-CLL clone. Interestingly, this M-clonotype was accompanied by many highly similar, less expanded “satellite” clonotypes (n=109), raising the possibility that SHM may be occurring in (pre-)CLL clones carrying truly unmutated IGHV genes, but pass unnoticed due to negative selection. Although their actual frequency cannot be conclusively determined due to the inherent limitations of PCR-based NGS analysis, subset-specific rearrangements represented a very minor fraction of the sequenced IGHV4/IGHM clonotypes in all cases tested (median frequency 0.04%). Overall, our findings suggest that while CLL clones are primed prior to CSR for malignant transformation on the basis of their BcR IG features, G-CLL quickly transits through CSR either because full-blown malignant transformation occurs at a later time point, or because CSR offers a selective advantage to the malignant clone. Disclosures No relevant conflicts of interest to declare.

Description: Chronic idiopathic neutropenia (CIN) is an acquired disorder of granulopoiesis characterized by prolonged neutropenia, mainly affecting middle-age females of the HLA-DRB1*1302 type. The defective hematopoiesis in CIN can be mainly attributed to accelerated Fas-mediated death of the CD34+/CD33+ granulocytic progenitors, secondary to an inflammatory bone marrow (BM) microenvironment. Crucial to CIN pathogenesis are the increased numbers of activated T cells identified in both peripheral blood (PB) and BM of CIN patients, supporting an immune pathogenesis. Using Sanger sequencing, we previously reported that the T-cell receptor (TR) gene repertoire in CIN is skewed, indicating antigen selection in CIN ontogeny. However, the analytical depth afforded by Sanger sequencing is limited, hindering definitive conclusions. In order to obtain a truly comprehensive view into the role of antigen drive in CIN, using next generation sequencing (NGS) we interrogated the TR repertoire of 13 patients (8 females, 5 males) included in our previous study as well as a healthy female. TRBV-TRBD-TRBJ gene rearrangements were amplified according to the BIOMED2 protocol on either genomic DNA or cDNA isolated from CD8+ cells of PB (n=4) or BM (n=10) samples. PCR products were used as a substrate for paired-end sample preparation (Illumina) and subjected to NGS on the MiSeq Illumina Platform. The raw NGS data were preprocessed with a dedicated pipeline for this purpose, including: (i) quality filtering of each read; (ii) merging of paired-end reads via local alignment; (iii) preparation of fasta files for submission to the IMGT/High V-QUEST tool; and, (iv) IMGT/High V-QUEST metadata analysis, interpretation and visualization. Overall, 6,196,980 TRBV-TRBD-TRBJ gene rearrangements were analyzed (130,020-1,037,680 /case) of which 5,317,609 were productive since they used functional TRBV genes and also carried in-frame CDR3. Rearrangements with identical TRBV gene usage and CDR3 sequence were defined as clonotypes. For repertoire analyses, clonotypes rather than single rearrangement sequences were considered. Overall, 553,145 unique clonotypes were identified (median 39,510; range 7,732-172,253/case), of which 408,744 represented singletons. All clonotypes from the Sanger analysis were detected by NGS as well. Among the 46 functional TRBV genes identified, the most frequent were: TRBV29-1 (13.9%), TRBV19 (6.7%), TRBV12-3 (5.6%), TRBV6-5 (5.4%), TRBV27 (4.9%) and TRBV6-1 (4.0%), collectively accounting for 40,5% of the TRBV repertoire; the TRBV29-1 gene predominated in 9/13 CIN cases. All CIN cases were found to carry distinct expanded clonotypes (median 10,314; range 2,279-40,245/case). The predominant clonotype ranged in frequency from 5.25 to 20.2% of the total clonotypes observed in each case. This contrasts significantly (p

Description: Chronic lymphocytic leukemia (CLL) is characterized by remarkable skewing of the B-cell receptor immunoglobulin (BcR IG) repertoire, culminating in the existence of subsets of patients with stereotyped BcR IGs. This implies antigen selection in the natural history of CLL, ultimately affecting clonal behavior. Currently, limited information is available regarding the role of antigens in the selection and activation of cognate T cells, although this is relevant in light of B and T cell interactions inducing T cell tolerance. Our preliminary next-generation sequencing (NGS) studies in 11 patients assigned to stereotyped subset #4, a clinically indolent disease subgroup, indicated T-cell receptor beta chain (TRB) gene repertoire restriction and oligoclonality. Prompted by these observations, here we sought to obtain a comprehensive view of the T-cell repertoire in CLL by extending our analysis to 36 untreated CLL patients, either assigned to major stereotyped subsets [subset #4 (n=11), subset #1 (n=10), subset #2 (n=4), subset #16 (n=1)] or non-subset cases [with mutated-M (n=5) or unmutated-UM clonotypic BcR IGs (n=5)]. Starting material was PB mononuclear cells (n=27), purified CD4+ and CD8+ T-cell subpopulations (n=10), bone marrow (n=2) or lymph node (LN) tissue (n=1). Three patients were studied overtime. Multiple sample and PCR replicates, as well as 3 age-matched healthy controls were also included. TRBV-TRBD-TRBJ gene rearrangements were amplified on cDNA (BIOMED2 protocol) and subjected to paired-end NGS, designed to cover the complementarity determining region 3 (CDR3) twice/sequence. In order to further increase the accuracy of results, raw NGS reads were subjected to a purpose-built, bioinformatics algorithm, performing: (i) length and quality filtering of raw reads; (ii) merging of filtered-in paired reads via local alignment; (iii) length and quality filtering of stitched sequences. No base calls of Q-score

Description: Chronic lymphocytic leukemia (CLL) is characterized by progressive hypogammaglobulinemia that can affect one or more immunoglobulin subclasses. Although many underlying mechanisms have been suggested, the pathogenesis of this phenomenon remains to be elucidated. In the present study, we revisit hypogammaglobulinemia in CLL through a combined clinicobiological approach aiming at identifying associations with particular disease profiles that would offer pathogenetic insight and guidance for further research. The study group included 412 CLL patients with available information about serum immunoglobulins either at diagnosis (n=380) or before treatment initiation (n=32). Patient characteristics were as follows: median age: 65 years; males/females: 266/146; Binet stage A: 272/335, unmutated IGHV genes (U-CLL): 140/412 cases (34%); CD38 expression: 59/330 cases (18%); clonotypic IG of the MD or G isotype: 250 and 43 cases, respectively; isolated del(13q): 64/136 (47%); trisomy 12: 18/183 (10%); del(11q): 18/186 (10%); del(17p): 11/189 (6%); NOTCH1 del7544-45/p.P2514Rfs*4: 8/219 (4%). With a median follow up of 5 years, 152/329 cases (46%) received treatment. Decreased immunoglobulin serum levels in at least one subclass were identified in 220/412 patients (53%), as follows: (i) decreased IgM, 172/412 cases (41%); (ii) decreased IgG, 78/412 cases (19%); (iii) decreased IgA, 100/412 cases (24%). In 36/412 cases (9%), a decrease in all serum immunoglobulin subclasses was noted. No statistically significant differences were identified between patients with normal serum immunoglobulin levels versus those with hypogammaglobulinemia regarding age, gender, disease burden at diagnosis, IGHV gene mutational status, CD38 expression, cytogenetic aberrations, NOTCH1 mutations and the incidence of a second malignancy. However patients with hypogammaglobulinemia exhibited increased need for treatment compared to patients with normal serum immunoglobulins (91/175 vs 61/154 respectively, p=0.025). Among cases with hypogammaglobulinemia, 90 (41%) and 26 (12%) exhibited isolated IgM and IgA subclass deficiency, respectively; isolated IgG decrease, was relatively rare (10/220 cases, 4%). Interestingly, when comparing isolated IgA versus other subclass deficiencies, statistically significant associations were identified with (i) advanced clinical stage (Binet B/C, Rai III/IV) (p=0.002); (ii) female gender (p=0.041); and, (iii) NOTCH1 mutations (p=0.004). A propos of the latter, it is noteworthy that in 5/8 (63%) mutant NOTCH1 cases with hypogammaglobulinemia, the affected subclass was IgA. Within our cohort, we identified cases belonging to one of three different, well characterized subsets with stereotyped B-cell receptor immunoglobulin (BcR IG), namely: (1) subset #1 (clan I IGHV genes/IGKV1(D)-39): U-CLL, clinically aggressive, n=12; (2) subset #2 (IGHV3-21/IGLV3-21), mixed IGHV mutational status, noted clinical aggressiveness, n=5; and, (3) subset #4, mutated IGHV4-34/IGKV2-30 BcR IG, clinically indolent, n=12. Notably, all subset #2 cases showed low levels of at least one serum subclass, while in 4/5 and 3/5 cases, two or all three immunoglobulin subclasses were affected. Although numbers are small, the incidence of hypogammaglobulinemia in subset #2 was significantly (p

Description: The human IGHV4-34 gene encodes antibodies which are intrinsically autoreactive when the VH domain is unmutated. Therefore, B cells expressing IGHV4-34 B-cell receptor immunoglobulins (BcR IG) are normally under close scrutiny in order to avoid unwanted autoreactivity, especially against DNA. The IGHV4-34 gene is frequently utilized in chronic lymphocytic leukemia (CLL), where, typically, it shows a high load of somatic hypermutation (SHM). We have previously reported distinctive SHM patterns amongst IGHV4-34 CLL, especially for subsets with stereotyped BcR IG. However, although a large number of cases (~2000) was previously studied, since even the largest subsets account for only ~3% of CLL, meaningful conclusions could not be reached for smaller subsets. Here we revisit this issue in a series of 16,528 CLL cases and focus on IGHV4-34 expressing subsets: #4 (IGHV4-34/IGHD5-18/IGHJ6 | 156 cases, 0.9%); #11 (IGHV4-34/IGHD3-10/IGHJ4 | 16 cases, 0.1%); #16 (IGHV4-34/IGHD2-15/IGHJ6 | 41 cases, 0.25%); #29 (IGHV4-34/IGHD: unassignable/IGHJ3 | 39 cases, 0.24%); and #201 (IGHV4-34/IGHD: unassignable/IGHJ3 | 43 cases 0.26%). Focusing on codons 27-104 within the VH domain (from CDR1-IMGT to FR3-IMGT), we calculated the sequence distance between subsets and the corresponding IGHV4-34 germline sequence based on a pairwise qualitative and quantitative comparison of the respective amino acid composition. The minimum distance calculated, and hence the greatest identity, was observed between subsets #4 and #16, both concerning IgG-switched cases (IgG-CLL), which is notable given the overall rarity of IgG-CLL. In contrast, the maximum distance, implying the least identity, was between subsets #16 and #201, the latter concerning IgM/D-CLL. Extreme variations between subsets were noted in codons spanning the entire VH domain. This result is consistent with our finding of a subset-biased distribution of mutations over the VH domain. More specifically, while subsets #11, #16, #29 and #201 had a lower frequency of mutations within VH CDR1 compared to VH CDR2, the exact opposite was seen in subset #4, with 40% of mutations in VH CDR1 versus 27% in VH CDR2. In addition, subsets #4, #11, #16 and #29 had a similar distribution of mutations in VH FR2 and VH FR3, in contrast to subset #201 that showed a preference for VH FR3 over VH FR2. Consequently, we noted that certain positions were targeted in a subset-specific manner e.g. codon 28 in VH CDR1 was heavily targeted in subsets #4 (68.6%) and #16 (87.8%), with most cases carrying an acidic amino acid (AA) introduced by SHM, glycine to glutamic acid, G〉E: 51.3% for subset #4 and 78% for subset #16. The high prevalence of acidic AA introduced by SHM in these subsets is notable considering the electropositive nature of their VH CDR3 (especially of subset #4), strongly recalling edited anti-DNA antibodies. Interestingly, the G〉E change was identified at a much lower frequency in other IGHV4-34 subsets: 18.75% for subset #11; 2.6% for subset #29; 7% for subset #201, all of which carried electronegative VH CDR3. Further, we noted that certain positions were heavily targeted in all subsets e.g. 56-86% targeting for SHM at codon 92 in VH FR3 where serine is encoded by the agc triplet, the ”hottest of hotspots”. This result could be viewed as sequence- rather than subset-dependent and linked to the molecular features of this codon, which is supported by the low targeting of codon 93 (0-6%), also encoding serine by the tct triplet. Other positions were targeted in all subsets but at vastly different frequencies e.g. codon 64 was targeted in 37.8% in subset #4 rising to 100% in subset #29. Finally, positions heavily targeted by SHM in certain subsets were unmutated in other subsets e.g. codon 36 in VH CDR1 remained unmutated in subset #16, in contrast 76.9% of subset #29 were mutated at this position resulting in an AA change. In conclusion, we document different spectra of SHM and AA changes between stereotyped IGHV4-34 CLL subsets. The finding of subset-biased, recurrent AA changes at certain codons indicates that the respective progenitor cells may have responded in a specific manner to the selecting antigen(s), despite expressing the same IGHV gene, indicating a functional purpose for these modifications. This is exemplified by the molecular characteristics of the recurrent AA changes in subset #4, thereby offering interesting pathogenetic hints. Disclosures No relevant conflicts of interest to declare.

Description: The role of antigen(s) in shaping the T-cell repertoire in chronic lymphocytic leukemia (CLL) is largely unexplored, though highly relevant in light of the interactions of the CLL B cells with T cells, effectively inducing tolerance to the latter. Our recent classic subcloning/Sanger sequencing studies of the T-cell receptor beta chain (TRB) gene repertoire in CLL indicated repertoire restriction, pointing to antigenic selection. However, due to the inherent limitations of low-throughput analysis, definitive conclusions were not possible. Here, we sought to advance the analytical depth of our approach by employing high-throughput, next generation sequencing (NGS) for exploring the TRB gene repertoire in CLL. Our study included 9 untreated CLL cases assigned to two paradigmatic stereotyped subsets, namely clinically indolent subset #4 (n=7) and clinically aggressive subset #1 (n=2). RNA was isolated from peripheral blood mononuclear cells (n=7 cases) or purified CD4+ and CD8+ T cells (n=2, both subset #4). TRBV-TRBD-TRBJ gene rearrangements were amplified on cDNA according to the BIOMED2 protocol and were subjected to NGS (MiSeq Illumina Platform). The paired-end Illumina protocol allowed sequencing of the complementarity determining region 3 (CDR3) twice/read, thus increasing the accuracy of results. Still, considering the inherent limitations of PCR-based NGS, the experimental setup included many internal controls: (i) replicate samples of the same patient at the same timepoint; (ii) samples of the same patient at sequential time points (two-timepoint longitutinal analysis for 1 case); (iii) replicate cDNA samples for PCR amplification; and, (iv) analysis of a healthy individual. A bioinformatics pipeline was developed for raw NGS data processing, performing: (i) quality filtering of reads; (ii) merging of paired-end reads via local alignment; (iii) preparation of filtered-in fasta sequences for submission to the IMGT/HighV-QUEST tool; and, (iv) IMGT/HighV-QUEST metadata clustering, analysis and interpretation. Overall, 19 samples were analyzed, producing 7,920,136 TRBV-TRBD-TRBJ reads (median 359,957 reads/sample, median Q-score 38.3). Poor quality, incomplete, out-of-frame and unproductive rearrangements were filtered out (median 2.1% of reads/sample). For repertoire analyses, clonotypes (i.e. TRB rearrangements with identical TRBV gene usage and amino acid CDR3 sequence) rather than single rearrangement reads were considered, so as to avoid possible biases due to clonal expansion following antigenic stimulation (median 56194 distinct clonotypes/sample, 33619 singletons versus 13725 expanded). Among the 53 functional TRBV genes identified, the following 5 predominated: TRBV12-3/12-4 (7.5%), TRBV19 (6.1%), TRBV5-1 (5.2%), TRBV29-1 (4.9%) and TRBV27 (4.8%), collectively accounting for 28.5% of the TRBV repertoire. Comparison of the TRBV gene repertoire of CD8+ vs CD4+ cells in subset #4 CLL cases showed that TRBV19 was overrepresented in the CD4+ compartment (9.4% versus 6.9%, p