Intestinal Epithelial Digestive, Transport, and Barrier Protein Expression Is Increased in Environmental Enteric Dysfunction.

Environmental enteric dysfunction (EED) is characterized by malabsorption and diarrhea that result in irreversible deficits in physical and intellectual growth. We sought to define the expression of transport and tight junction proteins by quantitative analysis of duodenal biopsies from patients with EED. Biopsies from Pakistani children with confirmed EED diagnoses were compared to those from age-matched North American healthy controls, patients with celiac disease, and patients with nonceliac disease with villous atrophy or intraepithelial lymphocytosis. Expression of brush border digestive and transport proteins and paracellular (tight junction) proteins was assessed by quantitative multiplex immunofluorescence microscopy. EED was characterized by partial villous atrophy and marked intraepithelial lymphocytosis. Epithelial proliferation and enteroendocrine, tuft, and Paneth cell numbers were unchanged, but there was significant goblet cell expansion in EED biopsies. Expression of proteins involved in nutrient and water absorption and that of the basolateral Cl- transport protein NKCC1 were also increased in EED. Finally, the barrier-forming tight junction protein claudin-4 (CLDN4) was significantly upregulated in EED, particularly within villous enterocytes. In contrast, expression of CFTR, CLDN2, CLDN15, JAM-A, occludin, ZO-1, and E-cadherin was unchanged. Upregulation of a barrier-forming tight junction protein and brush border and basolateral membrane proteins that support nutrient and water transport in EED is paradoxical, as their increased expression would be expected to be correlated with increased intestinal barrier function and enhanced absorption, respectively. These data suggest that EED activates adaptive intestinal epithelial responses to enhance nutrient absorption but that these changes are insufficient to restore health.

Insights on chronic hypersensitivity pneumonitis' treatment: Factors associated with a favourable response to azathioprine.

BACKGROUND: The use of immunosuppressive and antifibrotic agents for the treatment of chronic hypersensitivity pneumonitis (CHP) appears promising, but there is still no evidence supporting the clinical decision regarding the implementation of each specific pharmacological strategy. METHODS: Patients diagnosed with CHP and treated with azathioprine (AZA) were retrospectively selected from a single centre for Interstitial Lung Diseases. Baseline clinical data, as well as functional, imaging, bronchoalveolar lavage (BAL) and histology features were assessed. Longitudinal data on functional parameters were collected and comparatively analysed with patients' characteristics. RESULTS: In this cohort of 80 patients, of those who reached 12 months of treatment, 78.3% presented a preserved forced vital capacity, with 59 being eligible to be classified as AZA responders (n = 36) or non-responders (n = 23). BAL lymphocytosis was associated with a favourable response to AZA treatment (OR 1.051; 95% CI 1.015-1.089), although it didn't identify all responders. CONCLUSIONS: AZA revealed to be effective in disease stabilisation in most patients, while ineffective for a subset. BAL lymphocytosis appears as a potentially valuable strategy to identify AZA responders, although with limited accuracy. Further studies are needed to clarify other response markers to immunosuppressive agents, in order to optimize the therapeutic options for this condition.

Tumor mutational load predicts time to first treatment in chronic lymphocytic leukemia (CLL) and monoclonal B-cell lymphocytosis beyond the CLL international prognostic index.

Next-generation sequencing identified about 60 genes recurrently mutated in chronic lymphocytic leukemia (CLL). We examined the additive prognostic value of the total number of recurrently mutated CLL genes (i.e., tumor mutational load [TML]) or the individually mutated genes beyond the CLL international prognostic index (CLL-IPI) in newly diagnosed CLL and high-count monoclonal B-cell lymphocytosis (HC MBL). We sequenced 59 genes among 557 individuals (112 HC MBL/445 CLL) in a multi-stage design, to estimate hazard ratios (HR) and 95% confidence intervals (CI) for time-to-first treatment (TTT), adjusted for CLL-IPI and sex. TML was associated with shorter TTT in the discovery and validation cohorts, with a combined estimate of continuous HR = 1.27 (CI:1.17-1.39, P = 2.6 × 10-8 ; c-statistic = 0.76). When stratified by CLL-IPI, the association of TML with TTT was stronger and validated within low/intermediate risk (combined HR = 1.54, CI:1.37-1.72, P = 7.0 × 10-14 ). Overall, 80% of low/intermediate CLL-IPI cases with two or more mutated genes progressed to require therapy within 5 years, compared to 24% among those without mutations. TML was also associated with shorter TTT in the HC MBL cohort (HR = 1.53, CI:1.12-2.07, P = .007; c-statistic = 0.71). TML is a strong prognostic factor for TTT independent of CLL-IPI, especially among low/intermediate CLL-IPI risk, and a better predictor than any single gene. Mutational screening at early stages may improve risk stratification and better predict TTT.

T-cell large granular lymphocytic (LGL) leukemia consists of CD4+/CD8dim and CD4-/CD8+ LGL populations in association with immune thrombocytopenia, autoimmune neutropenia, and monoclonal B-cell lymphocytosis.

CD3+/CD57+ T-cell large granular lymphocyte leukemia (T-LGLL) is an indolent neoplasm, exhibiting mostly CD8+, less frequently CD4+ phenotypes, and T-LGLL consisting of 2 populations with CD8+ and CD4+ phenotypes is markedly rare. An 87-year-old female was admitted under a diagnosis of immune thrombocytopenia (ITP) with a platelet count of 5.0×109/L and increased number of LGL with unknown etiology. Her neutrophil count also decreased to 0.27×109/L and she was positive for antineutrophil antibody. The WBC count was 2.7×109/L with 34.7% LGL and flow cytometry (FCM) analysis revealed 16% CD3+/CD4+/CD8dim/CD57+ and 20.9% CD3+/CD8+/CD57+ populations. These populations also expressed granzyme B and perforin. Circulating mononuclear cells were found to be clonal by PCR analysis of T-cell receptor ß-chain gene. Serum immunofixation and bone marrow FCM analyses demonstrated 2 clonal B-cells producing IgG-λ and IgA-λ. Deep amplicon sequencing of STAT3 and STAT5B genes revealed a STAT3 R302G mutation with an allele burden of 2.6%. The thrombocytopenia and neutropenia were successfully treated by prednisolone and romiplostim with negative conversion of antineutrophil antibody. This is the first reported case of T-LGLL with dual components of CD4+/CD8dim and CD4-/CD8+ populations in terms of multiple comorbidities related to the respective CD8+ and CD4+ T-LGLLs.

T cell large granular lymphocyte leukemia and chronic NK lymphocytosis.

Large Granular Lymphocyte Leukemia (LGLL) is a rare chronic lymphoproliferative disorder characterized by the clonal expansion of Large Granular Lymphocytes (LGLs). Among LGLL, the 2016 WHO classification recognizes two different entities, i.e. T-LGLL and the provisional entity Chronic Lymphoproliferative disorder of NK cells (CLPD-NK). In both subtypes neutropenia represents the hallmark of the disease and is frequently regarded as the leading reason to start treatment. Leukemic LGLs are characterized by the up-regulation of several pro-survival signaling pathways, the most relevant being the JAK-STAT axis, whose constitutive activation is partly explained by somatic mutations in STAT3 and STAT5b. In addiction, in the last few years, a relationship between STAT3 mutations/activation and the development of neutropenia was found. Given that backbone treatment relying on immunosuppressive agents is generally unsatisfactory, novel agents targeting the JAK/STAT pathway can represent a turning point in LGLL treatment.

Blockage of autophagic flux is associated with lymphocytosis and higher percentage of tumoral cells in chronic lymphocytic leukemia of B cells.

PURPOSE: Autophagy has lately emerged as an important biological process with implications in several hematological pathologies. Recently, a growing body of evidence supports a putative role of autophagy in chronic lymphocytic leukemia; however, no definitive clue has been established so far. To elucidate this issue, we have developed a pilot study to measure autophagic flux in peripheral blood mononuclear cells from chronic lymphocytic leukemia patients, and explored its correlation with classical clinical/analytical parameters. METHODS/PATIENTS: Thirty-three chronic lymphocytic leukemia patients participated in the study. Autophagic flux in peripheral blood mononuclear cells was determined by western blot measuring the levels of the proteins p62 and lipidated LC3. Moreover, p62 mRNA levels were analyzed by RT-qPCR. RESULTS: Lymphocytosis and the percentage of tumoral lymphocytes in chronic lymphocytic leukemia patients statistically correlate with a blocked autophagic flux. CONCLUSION: Alterations in autophagic flux could play an important role in the physiopathology of chronic lymphocytic leukemia.

Accumulation of DNA damage and alteration of the DNA damage response in monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia.

Accumulation of DNA damage and alteration of the DNA damage response (DDR) are critical features of genetic instability that is presumed to be implicated in the pathogenesis of monoclonal B-cell lymphocytosis (MBL) and chronic lymphocytic leukemia (CLL). Here, we show increased numbers of γH2AX foci, a marker of DNA double-strand breaks (DSB), in CD19+ cells of CLL patients as compared to CD19+ cells of MBL patients and healthy individuals. Furthermore, numerous γH2AX/53BP1 foci in CLL cells suggest activation of error-prone non-homologous end-joining repair mechanisms. Signatures of DDR proteins further indicate alterations of the DDR in CLL in contrast to a largely regular activation in MBL and healthy controls. In summary, our results provide evidence for the stepwise accumulation of DNA damage in the progression of MBL towards CLL and suggest increased DNA damage, error-prone DNA repair and altered DDR signaling to be critical mechanisms of clonal evolution in MBL and CLL.

Functional and clinical relevance of VLA-4 (CD49d/CD29) in ibrutinib-treated chronic lymphocytic leukemia.

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib, which antagonizes B cell receptor (BCR) signals, demonstrates remarkable clinical activity in chronic lymphocytic leukemia (CLL). The lymphocytosis experienced by most patients under ibrutinib has previously been attributed to inhibition of BTK-dependent integrin and chemokine cues operating to retain the tumor cells in nodal compartments. Here, we show that the VLA-4 integrin, as expressed by CD49d-positive CLL, can be inside-out activated upon BCR triggering, thus reinforcing the adhesive capacities of CLL cells. In vitro and in vivo ibrutinib treatment, although reducing the constitutive VLA-4 activation and cell adhesion, can be overcome by exogenous BCR triggering in a BTK-independent manner involving PI3K. Clinically, in three independent ibrutinib-treated CLL cohorts, CD49d expression identifies cases with reduced lymphocytosis and inferior nodal response and behaves as independent predictor of shorter progression-free survival, suggesting the retention of CD49d-expressing CLL cells in tissue sites via activated VLA-4. Evaluation of CD49d expression should be incorporated in the characterization of CLL undergoing therapy with BCR inhibitors.

Increased naive CD4+ and B lymphocyte subsets are associated with body mass loss and drive relative lymphocytosis in anorexia nervosa patients.

Anorexia nervosa (AN) is an atypical form of malnutrition with peculiar changes in the immune system. We hypothesized that different lymphocyte subsets are differentially affected by malnutrition in AN, and thus, our aim was to investigate the influence of body mass loss on the variability of lymphocyte subsets in AN patients. A group of 66 adolescent female patients, aged 12-17 years, referred for their first episode of either AN or feeding or eating disorders not elsewhere classified were studied upon admission (46 AN-restricting subtype, 11 AN-binge/purging subtype, and 9 feeding or eating disorders not elsewhere classified). Ninety healthy adolescents served as controls. White blood cells and lymphocyte subsets were analyzed by flow cytometry. Relationships with the body mass index (BMI) z score were assessed in linear models adjusted by diagnostic subtype and age. Leukocyte numbers were lower in AN patients than in controls, and relative lymphocytosis was observed in AN-restricting subtype. Lower CD8+, NK, and memory CD8+ counts were found in eating disorder patients compared with controls. No differences were found for CD4+ counts or naive and memory CD4+ subsets between the groups. Negative associations between lymphocyte percentage and the BMI z score, as well as between the B cell counts, naive CD4+ percentage and counts, and the BMI z score, were found. In conclusion, increased naive CD4+ and B lymphocyte subsets associated with body mass loss drive the relative lymphocytosis observed in AN patients, which reflects an adaptive mechanism to preserve the adaptive immune response.

What does it mean I have a monoclonal B-cell lymphocytosis?: Recent insights and new challenges.

Monoclonal B-cell lymphocytosis (MBL) is defined as a laboratory abnormality where small (<5 x 10(9)/L) clonal B-cell populations are detected in the peripheral blood of otherwise healthy subjects. According to the immunophenotype, MBL is labeled as chronic lymphocytic leukemia (CLL)-like (75% of cases), atypical CLL, and CD5-negative. Concentration of clonal B cells differentiates low- (LC) and high-count (HC)-MBL (< or ≥ 0.5 x 10(9)/L, respectively). Thanks to technical improvements, we are able to identify CLL-like clonal B-cell populations at increased frequency with age, but we are still far from understanding its relationship with clinically overt CLL. LC-MBL, requiring high-throughput screening technique to be identified in population studies, seems to be a bird of a different feather and several hints suggest that LC-MBL is related to aging and/or chronic antigenic stimulation. Immunogenetic, cytogenetic and genetic data support the notion that HC-MBL, usually identified in the clinical setting, is a premalignant condition and, based on biological parameters, it is frequently difficult to differentiate it from early stage CLL. The rapid improvement and widespread availability of cutting-edge technology, in particular next-generation sequencing (NGS), raises hope that we are getting closer to unveiling the fundamental nature of MBL and CLL and how they are related to each other.

Treatment with Ibrutinib Inhibits BTK- and VLA-4-Dependent Adhesion of Chronic Lymphocytic Leukemia Cells In Vivo.

PURPOSE: Ibrutinib leads to a transient lymphocytosis in patients with chronic lymphocytic leukemia (CLL) that develops within hours of starting drug and is due to the efflux of cells from lymphoid tissues into the blood. We therefore sought to investigate the in vivo effect of ibrutinib on migration and adhesion of CLL cells. EXPERIMENTAL DESIGN: Patients received single-agent ibrutinib (420 mg daily) on an investigator-initiated phase II trial. Serial blood samples were collected pretreatment and during treatment for ex vivo functional assays. RESULTS: Adhesion of CLL cells to fibronectin was rapidly (within hours) and almost completely inhibited (median reduction 98% on day 28, P < 0.001), while the effect on migration to chemokines was more moderate (median reduction 64%, P = 0.008) and less uniform. Although cell surface expression of key adhesion molecules such as CD49d, CD29, and CD44 were modestly reduced, this was only apparent after weeks of treatment. Stimulation of CLL cells from patients on ibrutinib with PMA, which activates PKC independent of BTK, restored the ability of the cells to adhere to fibronectin in a VLA-4-dependent manner. Finally, the addition of ibrutinib to CLL cells adhered to fibronectin in vitro caused the detachment of 17% of the cells, on average; consisten t with in vivo observations of an increasing lymphocytosis within 4 hours of starting ibrutinib. CONCLUSIONS: Inhibition of BTK and VLA-4-dependent adhesion of CLL cells to stroma and stromal components provides a mechanistic explanation for the treatment-induced lymphocytosis and may reduce CD49d-dependent prosurvival signals in the tissue microenvironment.

A prognostic algorithm including a modified version of MD Anderson Cancer Center (MDACC) score predicts time to first treatment of patients with clinical monoclonal lymphocytosis (cMBL)/Rai stage 0 chronic lymphocytic leukemia (CLL).

We propose an algorithm based on a slightly modified version of MD Anderson Cancer Center (MDACC) score (i.e., mutational status of IgVH, LDH, presence of high-risk FISH abnormalities), ß2-microglobulin and separation of clinical monoclonal B-cell lymphocytosis (cMBL) from chronic lymphocytic leukemia (CLL) to predict time to first treatment (TTFT) of a prospective multicentre cohort including 83 cMBL and 136 CLL Rai stage 0 patients. Patients with MDACC score point ≥38, at any level of ß2-microglobulin and irrespective of whether they fulfilled 2008 International Workshop on CLL (IWCLL) criteria for CLL Rai stage 0 or cMBL, experienced the worst clinical outcome (5-year TTFT, 24%) and formed the high-risk group. In contrast, subjects with a diagnosis of cMBL, MDACC score point <38 and ß2-microglobulin ≤ UNL had the best clinical outcome (5-year TTFT, 100%) and constituted the low-risk group. The intermediate group included patients in Rai stage 0, MDACC score point <38, and any level of ß2-microglobulin, and patients with cMBL, MDACC score point <38, and ß2-microglobulin ≥ UNL. Cases showing these features can be grouped together to form the intermediate-risk group (5-year TTFT, 65%). Although the separation between cMBL and Rai stage 0, as proposed by the 2008 IWCLL guidelines, has clinical implications, the model we propose may help to classify patients with cMBL and Rai stage 0 into more precise subgroups suggesting that a prognostic separation of these entities based solely on clonal B-cell threshold may be unsatisfactory.

Distinction between asymptomatic monoclonal B-cell lymphocytosis with cyclin D1 overexpression and mantle cell lymphoma: from molecular profiling to flow cytometry.

PURPOSE: According to current diagnostic criteria, mantle cell lymphoma (MCL) encompasses the usual, aggressive variants and rare, nonnodal cases with monoclonal asymptomatic lymphocytosis, cyclin D1-positive (MALD1). We aimed to understand the biology behind this clinical heterogeneity and to identify markers for adequate identification of MALD1 cases. EXPERIMENTAL DESIGN: We compared 17 typical MCL cases with a homogeneous group of 13 untreated MALD1 cases (median follow-up, 71 months). We conducted gene expression profiling with functional analysis in five MCL and five MALD1. Results were validated in 12 MCL and 8 MALD1 additional cases by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and in 24 MCL and 13 MALD1 cases by flow cytometry. Classification and regression trees strategy was used to generate an algorithm based on CD38 and CD200 expression by flow cytometry. RESULTS: We found 171 differentially expressed genes with enrichment of neoplastic behavior and cell proliferation signatures in MCL. Conversely, MALD1 was enriched in gene sets related to immune activation and inflammatory responses. CD38 and CD200 were differentially expressed between MCL and MALD1 and confirmed by flow cytometry (median CD38, 89% vs. 14%; median CD200, 0% vs. 24%, respectively). Assessment of both proteins allowed classifying 85% (11 of 13) of MALD1 cases whereas 15% remained unclassified. SOX11 expression by qRT-PCR was significantly different between MCL and MALD1 groups but did not improve the classification. CONCLUSION: We show for the first time that MALD1, in contrast to MCL, is characterized by immune activation and driven by inflammatory cues. Assessment of CD38/CD200 by flow cytometry is useful to distinguish most cases of MALD1 from MCL in the clinical setting. MALD1 should be identified and segregated from the current MCL category to avoid overdiagnosis and unnecessary treatment.