Prediction of outcomes for high-count monoclonal B lymphocytosis using an epigenetic and immunogenetic signature.

ABSTRACT: Monoclonal B-cell lymphocytosis (MBL) progresses to chronic lymphocytic leukemia (CLL) requiring therapy at 1% to 5% per year. Improved prediction of progression would greatly benefit individuals with MBL. Patients with CLL separate into 3 distinct epigenetic subtypes (epitypes) with high prognostic significance, and recently the intermediate epitype has been shown to be enriched for high-risk immunoglobulin lambda variable (IGLV) 3-21 rearrangements, impacting outcomes for these patients. Here, we employed this combined strategy to generate the epigenetic and light chain immunoglobulin (ELCLV3-21) signature to classify 219 individuals with MBL. The ELCLV3-21 high-risk signature distinguished MBL individuals with a high probability of progression (39.9% and 71.1% at 5 and 10 years, respectively). ELCLV3-21 improved the accuracy of predicting time to therapy for individuals with MBL compared with other established prognostic indicators, including the CLL international prognostic index (c-statistic, 0.767 vs 0.668, respectively). Comparing ELCLV3-21 risk groups in MBL vs a cohort of 226 patients with CLL revealed ELCLV3-21 high-risk individuals with MBL had significantly shorter time to therapy (P = .003) and reduced overall survival (P = .03) compared with ELCLV3-21 low-risk individuals with CLL. These results highlight the power of the ELCLV3-21 approach to identify individuals with a higher likelihood of adverse clinical outcome and may provide a more accurate approach to classify individuals with small B-cell clones.

Lymphocytic Esophagitis: Current Understanding and Controversy.

This review summarizes our current understanding of lymphocytic esophagitis (LE), a novel form of chronic esophagitis that incorporates distinctive histologic, clinical, and endoscopic features. First described as a histologic entity, a diagnosis of LE requires intraepithelial lymphocytosis without significant granulocytic inflammation and some evidence of epithelial damage; the rationale for and studies supportive of these histologic criteria are discussed within. Clinically, the majority of patients who present with histologically confirmed LE are older women or patients with underlying immunologic abnormalities, such as Crohn disease, rheumatologic disorders, or common variable immunodeficiency. The most common presenting symptom of LE is dysphagia, and the endoscopic findings can vary from normal mucosa to mucosal changes that resemble eosinophilic esophagitis: edema, rings, furrows, and plaques. The incidence of luminal strictures and the persistent dysphagia and/or lymphocytosis present in some patients provide evidence that LE is a chronic inflammatory disorder, at least within a subset of individuals. Several histologic mimics of LE are examined, as are disagreements surrounding the LE diagnosis.

Humoral and cellular immune responses to recombinant herpes zoster vaccine in patients with chronic lymphocytic leukemia and monoclonal B cell lymphocytosis.

Monoclonal B-cell lymphocytosis (MBL) and chronic lymphocytic leukemia (CLL) are clonal B-cell disorders associated with an increased risk of infections and impaired vaccination responses. We investigated the immunogenicity of recombinant zoster vaccine (RZV) in these patients. Individuals with MBL/untreated CLL and Bruton tyrosine kinase inhibitor (BTKi)-treated CLL patients were given two doses of RZV separated by 2 months. Responses assessed at 3 and 12 months from the first dose of RZV by an anti-glycoprotein E ELISA antibody assay and by dual-color Interferon-γ and Interleukin-2FLUOROSPOT assays were compared to historic controls matched by age and sex. About 62 patients (37 MBL/untreated CLL and 25 BTKi-treated CLL) were enrolled with a median age of 68 years at vaccination. An antibody response at 3 months was seen in 45% of participants, which was significantly lower compared to historic controls (63%, p = .03). The antibody response did not significantly differ between MBL/untreated CLL and BTKi-treated CLL (51% vs. 36%, respectively, p = .23). The CD4+ T-cell response to vaccination was significantly lower in study participants compared to controls (54% vs. 96%, p < .001), mainly due to lower responses among BTKi-treated patients compared to untreated MBL/CLL (32% vs. 73%, p = .008). Overall, only 29% of participants achieved combined antibody and cellular responses to RZV. Among participants with response assessment at 12 months (n = 47), 24% had antibody titers below the response threshold. Hypogammaglobulinemia and BTKi therapy were associated with reduced T-cell responses in a univariate analysis. Strategies to improve vaccine response to RZV among MBL/CLL patients are needed.

A homozygous stop-gain variant in ARHGAP42 is associated with childhood interstitial lung disease, systemic hypertension, and immunological findings.

ARHGAP42 encodes Rho GTPase activating protein 42 that belongs to a member of the GTPase Regulator Associated with Focal Adhesion Kinase (GRAF) family. ARHGAP42 is involved in blood pressure control by regulating vascular tone. Despite these findings, disorders of human variants in the coding part of ARHGAP42 have not been reported. Here, we describe an 8-year-old girl with childhood interstitial lung disease (chILD), systemic hypertension, and immunological findings who carries a homozygous stop-gain variant (c.469G>T, p.(Glu157Ter)) in the ARHGAP42 gene. The family history is notable for both parents with hypertension. Histopathological examination of the proband lung biopsy showed increased mural smooth muscle in small airways and alveolar septa, and concentric medial hypertrophy in pulmonary arteries. ARHGAP42 stop-gain variant in the proband leads to exon 5 skipping, and reduced ARHGAP42 levels, which was associated with enhanced RhoA and Cdc42 expression. This is the first report linking a homozygous stop-gain variant in ARHGAP42 with a chILD disorder, systemic hypertension, and immunological findings in human patient. Evidence of smooth muscle hypertrophy on lung biopsy and an increase in RhoA/ROCK signaling in patient cells suggests the potential mechanistic link between ARHGAP42 deficiency and the development of chILD disorder.

Performance of a diagnostic algorithm for fibrotic hypersensitivity pneumonitis. A case-control study.

BACKGROUND: The differential diagnosis fibrotic hypersensitivity pneumonitis (HP) versus idiopathic pulmonary fibrosis (IPF) is important but challenging. Recent diagnostic guidelines for HP emphasize including multidisciplinary discussion (MDD) in the diagnostic process, however MDD is not comprehensively available. We aimed to establish the diagnostic accuracy and prognostic validity of a previously proposed HP diagnostic algorithm that foregoes MDD. METHODS: We tested the algorithm in patients with an MDD diagnosis of fibrotic HP or IPF (case control study) and determined diagnostic test performances for diagnostic confidences of ≥ 90% and ≥ 70%. Prognostic validity was established using Cox proportional hazards models. RESULTS: Thirty-one patients with fibrotic HP and 50 IPF patients were included. The algorithm-derived ≥ 90% confidence level for HP had high specificity (0.94, 95% confidence interval [CI] 0.83-0.99), but low sensitivity (0.35 [95%CI 0.19-0.55], J-index 0.29). Test performance was improved for the ≥ 70% confidence level (J-index 0.64) with a specificity of 0.90 (95%CI 0.78-0.97), and a sensitivity of 0.74 (95%CI 0.55-0.88). MDD fibrotic HP diagnosis was strongly associated with lower risk of death (adjusted hazard ratio [HR] 0.10 [0.01-0.92], p = 0.04), whereas the algorithm-derived ≥ 70% and ≥ 90% confidence diagnoses were not significantly associated with survival (adjusted HR 0.37 [0.07-1.80], p = 0.22, and adjusted HR 0.41 [0.05-3.25], p = 0.39, respectively). CONCLUSION: The algorithm-derived ≥ 70% diagnostic confidence had satisfactory test performance for MDD-HP diagnosis, with insufficient sensitivity for ≥ 90% confidence. The lowest risk of death in the MDD-derived HP diagnosis validates the reference standard and suggests that a diagnostic algorithm not including MDD, might not replace the latter.

The CLL International Prognostic Index predicts outcomes in monoclonal B-cell lymphocytosis and Rai 0 CLL.

The utility of the chronic lymphocytic leukemia-international prognostic index (CLL-IPI) in predicting outcomes of individuals with Rai 0 stage CLL and monoclonal B-cell lymphocytosis (MBL) is unclear. We identified 969 individuals (415 MBL and 554 Rai 0 CLL; median age, 64 years; 65% men) seen at Mayo Clinic between 1 January 2001 and 1 October 2018, and ascertained time to first therapy (TTFT) and overall survival (OS). After a median follow up of 7 years, the risk of disease progression needing therapy was 2.9%/y for MBL (median, not reached) and 5%/y for Rai 0 CLL (median, 10.4 years). Among patients with low, intermediate, and high/very high-risk CLL-IPI risk groups, the estimated 5-year risk of TTFT was 13.5%, 30%, and 58%, respectively, P< .0001 (c-statistic = 0.69); and the estimated 5-year OS was 96.3%, 91.5%, and 76%, respectively, P< .0001 (c-statistic = 0.65). In a multivariable analysis of absolute B-cell count with individual factors of the CLL-IPI, the absolute B-cell count was associated with shorter TTFT (hazard ratio [HR] for each 10 × 109/L increase: 1.31; P< .0001) and shorter OS (HR: 1.1; P = .02). The OS of the entire cohort was similar to that of the age- and sex-matched general population of Minnesota (P = .17), although Rai 0 CLL patients with high and very high-risk CLL-IPI score had significantly shorter OS (P= .01 and P= .0001, respectively). The results of this study demonstrate the ability of CLL-IPI to predict time from diagnosis to first treatment (an end point not affected by therapy) in a large cohort of patients whose only manifestation of disease is a circulating clonal lymphocyte population.

Impact of bronchoalveolar lavage lymphocytosis on the effects of anti-inflammatory therapy in idiopathic non-specific interstitial pneumonia, idiopathic pleuroparenchymal fibroelastosis, and unclassifiable idiopathic interstitial pneumonia.

BACKGROUND: Idiopathic non-specific interstitial pneumonia (iNSIP), idiopathic pleuroparenchymal fibroelastosis (iPPFE), and unclassifiable idiopathic interstitial pneumonia (IIP) are IIPs with chronic fibrotic phenotypes, and unlike idiopathic pulmonary fibrosis, they have often been treated with anti-inflammatory drugs, including corticosteroids and immunosuppressants. However, the impact of bronchoalveolar lavage (BAL) lymphocytosis on the effects of anti-inflammatory therapy has never been evaluated. This study aimed to elucidate whether BAL lymphocytosis can be used to predict the efficacy of anti-inflammatory drugs for iNSIP, iPPFE, and unclassifiable IIP. METHODS: Japanese patients diagnosed with iNSIP, iPPFE, and unclassifiable IIP by multidisciplinary discussion were identified using the nationwide registry. Eligible patients were stratified into four groups with and without BAL lymphocytosis and anti-inflammatory therapy to compare overall survival (OS) and changes in lung function. BAL lymphocytosis was defined as a lymphocyte differential count > 15%, and the cut-off was corroborated by survival classification and regression tree analysis. RESULTS: Overall, 186 patients (37 iNSIP, 16 iPPFE, and 133 unclassifiable IIP) were analyzed. Limited to patients treated with anti-inflammatory drugs (n = 123), patients with BAL lymphocytosis had a better prognosis [hazard ratio (HR), 0.26; 95% confidence interval (CI), 0.11-0.63; P = 0.003], higher slope of forced vital capacity (FVC) % predicted for 2 years, and longer OS (log-rank test, P = 0.012) than those without BAL lymphocytosis. On multivariate analysis, BAL lymphocytosis (HR 0.31; 95% CI 0.13-0.75; P = 0.009) was a prognostic factor for OS, along with age and FVC % predicted. Conversely, for patients managed without anti-inflammatory therapy (n = 63), the presence or absence of BAL lymphocytosis had no prognostic value. CONCLUSIONS: BAL lymphocytosis is associated with good outcomes in patients treated with anti-inflammatory drugs, but has no prognostic value when anti-inflammatory drugs are not used. BAL lymphocytosis may provide a predictive biomarker for identifying patients with iNSIP, iPPFE and unclassifiable IIP who are likely to benefit from anti-inflammatory drugs.

Peripheral blood T lymphocytosis in thymoma: an insight into immunobiology.

PURPOSE: Peripheral blood T lymphocytosis (PBTL) is a rare, yet poorly understood manifestations of thymoma, which is postulated to be linked with autoimmune/paraneoplastic manifestations such as myasthenia gravis (MG), pure red cell aplasia (PRCA), etc.; more commonly encountered in this neoplasm. METHOD: We aim to describe the flowcytometric immunophenotypic data of PBTL in a 43-year-old male; 6 months after successful completion of chemoradiotherapy (CT/RT) for a large, invasive, and metastatic type B1 thymoma; and present a comprehensive review of all such cases reported over last 42 years (N = 21) (1977-2019). RESULT: A larger size of the tumors (≥ 10 cm), presence of local invasion and/or distant metastasis, and type B (cortical or lymphocyte rich) histology were more likely to be associated with PBTL. Tumors associated with MG/PRCA (N = 9/21) tend to have lower PBTL compared to those without such manifestations; and PBTL subsided following thymectomy with or without CT/RT. Immunophenotypic analysis of PB revealed a CD8 + > CD4 + mature (naïve) polyclonal T cells resembling late cortical thymocytes. CONCLUSION: Thymic intratumoral microenvironment might influence occurrence PBTL that may have a pathophysiologic link to development of autoimmune manifestations. Immunophenotypic characteristics of peripheral blood lymphoid cells should be the clue for accurate characterization and to avoid a misdiagnosis of a lymphoproliferative neoplasm.

[Characterization of B1-cells during experimental leukomogenesis.]

BACKGROUND: Bovine leukemia causes a significant polyclonal expansion of CD5+, IgM+ B lymphocytes, known as persistent lymphocytosis (PL), in approximately 30% of infected cattle. However, it is not yet clear what happens to this subpopulation of B cells in the early period of infection of animals. PURPOSE: Quantitative characterization of IgM+ and CD5+ B cells during the immune response, which can provide important information on the mechanisms of lymphocyte priming in BLV infection. MATERIAL AND METHODS: The experiment used BLV-negative calves of black-motley breed at the age of 8 months (n = 11). Animals (n = 8) were intravenously injected with blood of a BLV-positive cow. Control calves (n = 3) were injected with saline. Studies were performed before and after infection on days 5, 7, 14, 21, 28 and 65 of the immune response. The determination of the number of B-lymphocytes in the blood was carried out by the method of immunoperoxidase staining based on monoclonal antibodies to IgM, CD5. RESULTS: As a result of the studies, it was found that the level of CD5+ B cells increases on the 14th day of the primary immune response, characterized by polyclonal proliferation of CD5+ B cells, which are the primary target for BLV. Our research data confirm that in the lymphocytes of experimentally infected cattle, surface aggregation of IgM and CD5 molecules on B-lymphocytes is absent. DISCUSSION: It is known that the wave-like nature of IgM synthesis, which was shown in previous studies, depends on a subpopulation of B1 cells. After 7 days of the immune response, IgM+ and CD5+ cells do not correlate, which shows their functional difference. The increase in CD5+ cells is probably not associated with B cells, but with T cells differentiating under the influence of the virus. CONCLUSIONS: A subset of B1 cells is the primary target of cattle leukemia virus. The 65th day of the immune response is characterized by the expansion of IgM+ B cells, a decrease in the number of CD5+ cells and a uniform distribution of receptors around the perimeter of the cells.

Case report: Headache and neurological deficits with CSF lymphocytosis (HaNDL) associated with P/Q type voltage-gated calcium channel antibodies (CACNA1A).

BACKGROUND: Headache and Neurological Deficits with cerebrospinal fluid (CSF) Lymphocytosis (HaNDL) is an increasingly recognised syndrome but the aetiology remains unclear. HaNDL has striking clinical features similar to Familial Hemiplegic Migraine (FHM), commonly related to gene mutations encoding the P/Q-type voltage-gated calcium channel (VGCC). CASE REPORT: We report a case of HaNDL associated with high P/Q-type voltage-gated calcium channel antibodies. Extensive investigations excluded alternative diagnoses and CSF lymphocytosis resolved within 3 months. The case was complicated by raised intracranial pressure resulting in an enlarged blind spot, papilloedema and bilateral lateral rectus palsies. CONCLUSION: This novel association of P/Q-type voltage-gated calcium channel antibodies with HaNDL has implications for the pathology of HaNDL and spectrum of voltage-gated calcium channel-antibody disorders. We compare the clinical features of FHM and HaNDL and the potential pathological role of these antibodies. This case also highlights that raised intracranial pressure is a common feature of HaNDL, rarely resulting in serious complications.

Lymphocyte-predominant Esophagitis: A Distinct and Likely Immune-mediated Disorder Encompassing Lymphocytic and Lichenoid Esophagitis.

Lymphocytic esophagitis is a well-known manifestation of Crohn disease among children but is not considered to be an immune-mediated mucositis in adults. We hypothesize that adult-onset lymphocyte-predominant esophagitis is also an immune-mediated inflammatory pattern, the nature of which has been masked by other conditions that feature esophageal lymphocytosis and occur in older patients. We performed this study to consolidate diagnostic criteria for lymphocyte-predominant esophagitis and determine its clinical significance. We identified 61 patients with lymphocyte-rich inflammation in the mid or proximal esophagus, none of whom had another explanation for esophageal lymphocytosis. Affected patients were usually older adults and 72% were women. Most (56%) presented with dysphagia and 34% had eosinophilic esophagitis-like changes with rings, exudates, and/or edematous mucosa and linear furrows. Intraepithelial lymphocytosis was accompanied by mucosal injury featuring edema, basal zone hyperplasia, and scattered dyskeratotic cells. Some cases displayed occasional neutrophils or even superficial microabscesses; eosinophils were consistently infrequent. Most (67%) patients had at least 1 systemic immune-mediated disorder, particularly Crohn disease (30%) and connective tissue diseases (23%); only 1 had mucocutaneous lichen planus. We conclude that mild mucosal lymphocytosis (ie, ≥20 lymphocytes/HPF) alone is a frequent and nonspecific finding; criteria for lymphocyte-predominant esophagitis should include evidence of mucosal injury and allow for more than the occasional neutrophil. When this diagnosis is limited to cases that feature lymphocytosis unattributed to acid reflux, motility disorders, or infection, lymphocyte-predominant esophagitis may represent an immune-mediated disorder with characteristic clinical manifestations and a predilection for middle-aged women.

Immunophenotypic characterization and clinical outcome in cats with lymphocytosis.

BACKGROUND: Lymphocytosis is relatively common in cats, but few studies describe lymphocyte populations or the clinical course associated with different immunophenotypic expansions. HYPOTHESIS/OBJECTIVES: We hypothesized that cats frequently develop non-neoplastic lymphocytosis and that different neoplastic immunophenotypes have variable prognoses. We aimed to characterize the lymphocyte expansions in a large population of cats with lymphocytosis and to assess clinical presentation and outcome in a subset. ANIMALS: Three cohorts of cats older than 1 year with lymphocytosis (>6000/µL) were examined to define immunophenotypic categories (n = 146), evaluate outcome (n = 94), and determine prevalence of immunophenotypes (n = 350). METHODS: Retrospective study of cats with blood submitted for flow cytometry. Medical records (n = 94) were reviewed for clinical data, treatment, and survival information. RESULTS: Five major immunophenotypic categories were identified: B cell, heterogeneous (≥2 lineages expanded), CD4+ T cell, CD4-CD8- (double negative [DN]) T cell, and CD5-low-expressing T cell. B-cell and heterogeneous phenotypes were more consistent with a non-neoplastic process, having polyclonal antigen receptor gene rearrangements, younger age at presentation, lower lymphocyte counts, and prolonged survival. The neoplastic phenotypes, CD4+ T cell, DN T cell, and CD5 low T cell, had different median survival times (752 days [n = 37], 271 days [n = 7], 27.5 days [n = 12], respectively). Among CD4+ T-cell cases, cats with abdominal lymphadenopathy, intestinal involvement, or both and females had shorter survival. Among 350 cats with lymphocytosis, CD4+ T-cell lymphocytosis was most common, followed by heterogeneous and B-cell phenotypes. CONCLUSIONS AND CLINICAL IMPORTANCE: Neoplastic CD4+ T-cell lymphocytosis is common in cats and has a prolonged clinical course compared to aberrant T-cell phenotypes. Cats with heterogeneous and B-cell lymphocyte expansions commonly have non-neoplastic disease.

Monoclonal B-cell lymphocytosis.

Flow cytometry diagnostic practices can detect very low levels of clonal B cells in the peripheral blood. In the absence of clinical symptoms, cytopenia or organomegaly, the small clones may correspond to monoclonal B-cell leukemia (MBL) diagnosis. Most MBLs harbor a chronic lymphocytic leukemia (CLL) phenotype (e.g., CD5+, CD23+) and are referred to as CLL-type MBL. The two other types are atypical CLL-type MBL and non-CLL-type MBL. In addition to the phenotypical classification, the clonal B count is a major issue because of the impact on the prognosis and the risk of progression in CLL. It allows for the discrimination of two distinct types: high-count (HC) MBL and low-count (LC)-MBL based on a cutoff value of 0.5 × 109/L clonal B cells. LC MBL appears to be very stable over time and is probably related to immunosenescence. Conversely, HC MBL could be a premalignant state before the occurrence of CLL.

SDHA gain-of-function engages inflammatory mitochondrial retrograde signaling via KEAP1-Nrf2.

Whether screening the metabolic activity of immune cells facilitates discovery of molecular pathology remains unknown. Here we prospectively screened the extracellular acidification rate as a measure of glycolysis and the oxygen consumption rate as a measure of mitochondrial respiration in B cells from patients with primary antibody deficiency. The highest oxygen consumption rate values were detected in three study participants with persistent polyclonal B cell lymphocytosis (PPBL). Exome sequencing identified germline mutations in SDHA, which encodes succinate dehydrogenase subunit A, in all three patients with PPBL. SDHA gain-of-function led to an accumulation of fumarate in PPBL B cells, which engaged the KEAP1-Nrf2 system to drive the transcription of genes encoding inflammatory cytokines. In a single patient trial, blocking the activity of the cytokine interleukin-6 in vivo prevented systemic inflammation and ameliorated clinical disease. Overall, our study has identified pathological mitochondrial retrograde signaling as a disease modifier in primary antibody deficiency.

Association of elevated serumfree light chains with chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis.

Chronic lymphocytic leukemia (CLL) and its precursor, monoclonal B-cell lymphocytosis (MBL), are heritable. Serumfree light-chain (sFLC) measures are a prognostic factor for CLL, but their role in susceptibility to CLL is not clear. We investigated differences between sFLC measurements in pre-treatment serum from five groups to inform the association of sFLC with familial and sporadic CLL: (1) familial CLL (n = 154), (2) sporadic CLL (n = 302), (3) familial MBL (n = 87), (4) unaffected first-degree relatives from CLL/MBL families (n = 263), and (5) reference population (n = 15,396). The percent of individuals having elevated monoclonal and polyclonal sFLCs was compared using age-stratified and age- and sex-adjusted logistic regression models. In age groups >50 years, monoclonal sFLC elevations were increased in sporadic and familial CLL cases compared to the reference population (p's < 0.05). However, there were no statistically significant differences in sFLC monoclonal or polyclonal elevations between familial and sporadic CLL cases (p's > 0.05). Unaffected relatives and MBL cases from CLL/MBL families, ages >60 years, showed elevated monoclonal sFLC, compared to the reference population (p's < 0.05). This is the first study to demonstrate monoclonal sFLC elevations in CLL cases compared to controls. Monoclonal sFLC levels may provide additional risk information in relatives of CLL probands.

Quantification and phenotypic characterization of peripheral blood Vδ1 + T cells in chronic lymphocytic leukemia and monoclonal B cell lymphocytosis.

BACKGROUND: Vδ1+ T cells, a subset of γδ T cells, are responsible for innate-like immune responses. Recently, an anti-tumor function mediated by MHC-unrestricted recognition of lipid and stress molecules, has also been described in these cells. This study aimed to quantify and phenotypically characterize circulating Vδ1+ T cells in B cell Chronic Lymphocytic Leukemia (CLL) and Monoclonal B cell lymphocytosis (MBL). METHODS: This study enrolled 58 individuals distributed in five groups: Binet B and C CLL (n = 9), Binet A CLL (n = 26), High count-MBL (n = 10), Low count-MBL (n = 5), and a control group (n = 8). The phenotypic characterization of Vδ1+ T cells, as well as the other T cell subpopulations (CD4+ , CD8+ , CD4+ /CD8+ , and Vδ1- γδT cells), were assessed by flow cytometry, evaluating the frequency of each subset expressing CD27, CD69, and cytoplasmic granzyme B. RESULTS: We observed an increasing percentage of Vδ1+ T cells belonging to CD27- compartment from controls to advanced stages of the disease, which was accompanied by an increasing percentage of these cells expressing granzyme B, a phenotypic pattern that was also observed in the other T cell subpopulations under study since earlier stages of the disease. Moreover, a striking expansion of Vδ1+ T cells in Binet B and C CLL was observed. CONCLUSIONS: These experiment findings point to an expansion of CD27- Vδ1+ T cells with a cytotoxic profile, from controls to advanced stages of the disease, which points to a role of Vδ1+ T cells in the host's anti-tumor responses against clonal B-cells in MBL and CLL. © 2018 Clinical Cytometry Society.

Monoclonal B-cell lymphocytosis with renal involvement.

We report the case of a 70-year-old man with no relevant past medical history who presented with acute kidney injury. Kidney biopsy showed diffuse interstitial infiltration with typical chronic lymphocytic leukemia (CLL) phenotype B-cells. Subsequent studies revealed a normal lymphocyte count in the peripheral blood, and there was no evidence of lymphadenopathy or hepatosplenomegaly. Blood flow cytometry demonstrated a clonal B-cell population with a CLL phenotype. Without renal involvement, this case should be classified as monoclonal B-cell lymphocytosis. Renal function improved with steroid therapy. However, the patient developed CLL with significant lymphocytosis approximately two years later.