SEARCH · PubMed Health

Results for “LYMPHOCYTOSIS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

PubMed1996

Colonic epithelial lymphocytosis associated with an epidemic of chronic diarrhea.

The term Brainerd diarrhea has been applied to outbreaks of chronic watery diarrhea of unknown etiology characterized by acute onset and prolonged duration. Our aim was to describe the histologic changes in gastrointestinal biopsy specimens from patients with Brainerd diarrhea. We examined 52 colonic and 12 small bowel biopsy specimens from 22 patients who were involved in an outbreak of Brainerd diarrhea that was linked to the water supply of a cruise ship visiting the Galapagos Islands. Small bowel biopsy specimens from seven patients were histologically normal. One patient had a duodenal biopsy specimen that resembled celiac sprue. Colonic biopsy specimens from 20 patients revealed surface epithelial lymphocytosis without distortion of mucosal architecture, surface degenerative changes, or thickened subepithelial collagen plates. The degree of surface epithelial lymphocytosis was greater than that seen in control groups of persons with normal colons, acute colitis, and ulcerative colitis (p < 0.001), similar to that seen with collagenous colitis, and less than that seen with lymphocytic colitis (p < 0.001). Three patients showed focal active colitis similar to that described in acute infectious-type colitis in addition to the epithelial lymphocytosis. Two patients had colonic biopsy specimens that were histologically normal. In summary, histologic abnormalities in the small bowel are generally absent in Brainerd diarrhea. Colonic biopsy specimens in Brainerd diarrhea frequently show epithelial lymphocytosis similar to that seen in collagenous and lymphocytic colitis. Although currently Brainerd diarrhea can be diagnosed only with epidemiologic data indicating an epidemic and a point source, the lack of surface degenerative changes and the relatively lower lymphocyte counts seen in our cases of Brainerd diarrhea may serve to distinguish it from lymphocytic colitis, and the lack of a thickened subepithelial collagen plate distinguishes it from collagenous colitis.

Adult↗

PubMed1999

Colonic epithelial lymphocytosis without a thickened subepithelial collagen table: a clinicopathologic study of 40 cases supporting a heterogeneous entity.

Lymphocytic colitis (LC) is classically described as a triad of chronic nonbloody, watery diarrhea, normal or nearly normal endoscopy findings, and colonic epithelial lymphocytosis without a thickened subepithelial collagen table (SECT). It is unknown how often patients with colonic epithelial lymphocytosis without a thickened SECT actually present with this classic triad. Cases diagnosed histologically as lymphocytic or microscopic colitis were reviewed. Criteria for inclusion were the presence of at least 15 surface lymphocytes per 100 epithelial cells and the absence of a thickened SECT (<12 microm). Clinical features and course were recorded by chart review and telephone follow-up. Forty patients met the inclusion criteria, including 25 women and 15 men with a mean age of 63.2 years (range, 25-83 years). Twenty-eight patients had the classic triad and were designated as having classic LC. The other 12 patients fulfilled the histologic criteria but not the clinical or endoscopic criteria for classic LC and were classified as having atypical LC (constipation, five patients; macroscopic colitis at endoscopy, five patients; hematochezia, one patient; and incidental finding, one patient). Clinically, patients with classic LC were predominantly women and had a higher incidence of autoimmune disease (p = 0.03) than did those with atypical LC. Histologically, surface eosinophilia was significantly greater in patients with classic LC (p = 0.04). Twenty patients were using nonsteroidal antiinflammatory drugs at the time of their colonic biopsy. Surface epithelial lymphocyte counts were higher in these patients, particularly in the distal sigmoid colon (p = 0.02). Fourteen patients had associated autoimmune disease, including three patients with sprue diagnosed by small bowel biopsy, all of whom responded to gluten withdrawal. Diarrhea present in 25 patients, without documented evidence of celiac sprue, was self-limited in five, resolved with treatment in three, required intermittent treatment in eight, daily treatment in five, and was refractory to treatment in four. All eight patients who experienced spontaneous or treatment-related symptom resolution had classic LC. No histologic feature correlated with clinical course. In conclusion, our study shows that colonic epithelial lymphocytosis without a thickened SECT is a histologic finding seen in a heterogeneous group of patients. Within this heterogeneous group is a distinct subset of patients who have the classic clinicopathologic triad of LC. This subset of patients has striking similarities to patients with collagenous colitis, lending further support to a close relationship between these two entities. Atypical LC comprises a heterogeneous group and includes patients with idiopathic constipation, coexisting LC and inflammatory bowel disease, and possibly infectious colitides. Because of the clinical heterogeneity among our study population, the descriptive term colonic epithelial lymphocytosis may be a more prudent diagnosis than lymphocytic colitis in the absence of adequate clinical information.

Adult↗

PubMed1988

BoLA antigens are associated with increased frequency of persistent lymphocytosis in bovine leukaemia virus infected cattle and with increased incidence of antibodies to bovine leukaemia virus.

The association between bovine major histocompatibility system (BoLA) type and persistent lymphocytosis in cattle with antibodies to bovine leukaemia virus was examined by comparing antigen frequencies in cattle with persistent lymphocytosis to controls matched for age, sex, breed and presence of antibodies to BLV. The cattle came from nine dairy herds in south-east Queensland, Australia; six herds were Australian Illawarra Shorthorn (AIS), two herds were Jersey and one herd was Friesian. Antigen W6 and Eu28R were more common in cattle with persistent lymphocytosis than in controls. Antigen W8 was less common in AIS cattle with persistent lymphocytosis. A study of 24 offspring from one sire, heterozygous for W10 and Eu28R, showed that offspring inheriting Eu28R from the sire were significantly more likely to have antibodies to BLV than offspring inheriting the opposing W10 haplotype.

Animals↗

PubMed1975

Polymethacrylic acid: induction of lymphocytosis and tissue distribution.

Polmethacrylic acid (PMAA) induces up to a three-fold increase in the lymphocyte population of peripheral blood in rats, goats and calves after intravenous administration. Other routes of administration are less effective. A maximum lymphocytosis is achieved after 3 hr with all doses in excess of 30 mg PMAA/kg body weight; over the next few hours the lymphocyte level declines to normal. Granulocytes increase steadily for the first 7 hr before declining. Multiple doses of PMAA 2 hr apart failed to maintain or significantly alter the lymphocytosis. PMAA was labelled with 125I and 14C, and was traced to various sites in the rat. The greatest accumulation of radioactivity was in the spleen, lungs, liver, kidney, adrenals and mesenteric lymph nodes (with 14C-PMAA). The accumulation appeared more specific for spleen and lymph nodes since there was only a small loss of activity following removal of blood by whole body perfusion. This supports previous findings indicating that these two tissues play a major role in the development of lymphocytosis. Accumulation in the bone marrow may be indicative of stem cell mobilization. The results are discussed in terms of the lymphocytosis-inducing mechanism and the site of action of PMAA and the possible clinical application to ECIB therapy is considered.

Acrylic Resins↗

PubMed1986

Persistent high alveolar lymphocytosis as a predictive criterion of chronic pulmonary sarcoidosis.

A homogeneous population of 73 sarcoidosis patients with recent onset sarcoidosis, no smoking habits, and no previous treatments was serially evaluated in a study of the spontaneous evolution of sarcoidosis. This evaluation comprised clinical, radiographic, biological, and functional assessments as well as assessments of fluids recovered by BAL. We determined the natural history of alveolar lymphocytosis in early stage sarcoidosis and the predictive value of such lymphocytosis for the outcome of the disease. We focused on the outcome at 2 years because it is the usual time of spontaneous recovery; after 2 years the disease enters the chronic phase, and more complications are likely to occur. We found that the initial lymphocytosis observed during the very early stages of the disease had no predictive value for the outcome. Conversely, the persistence of a high alveolar lymphocytosis within the first year of evolution is strongly correlated to a nonrecovery at 2 years, and thus to a chronic phase of sarcoidosis.

Adult↗

PubMed1998

B-lymphocyte proliferation during bovine leukemia virus-induced persistent lymphocytosis is enhanced by T-lymphocyte-derived interleukin-2.

Bovine leukemia virus (BLV)-induced persistent lymphocytosis is characterized by a polyclonal expansion of CD5+ B lymphocytes. To examine the role of the cytokine microenvironment in this virus-induced B-lymphocyte expansion, the expression of interleukin-2 (IL-2), IL-4, IL-10, and gamma interferon (IFN-gamma) mRNA, was measured in stimulated peripheral blood mononuclear cells from persistently lymphocytotic BLV-infected cows, nonlymphocytotic BLV-infected cows, and uninfected cows. IL-2 and IL-10 mRNA expression and IL-2 functional activity were significantly increased when peripheral blood mononuclear cells from persistently lymphocytotic cows were stimulated with concanavalin A (ConA). Additionally, during persistent lymphocytosis, peak IL-2 and IL-10 mRNA expression was delayed, and elevated expression was prolonged. To determine the potential biologic importance of increased IL-2 and IL-10 expression, the response of isolated B lymphocytes from persistently lymphocytotic cows to human recombinant cytokines and to cytokine-containing supernatants from isolated T lymphocytes was examined. While recombinant human IL-10 (rhIL-10) did not consistently induce detectable changes, rhIL-2 increased viral protein (p24) and IL-2 receptor expression in isolated B lymphocytes from persistently lymphocytotic cows. Additionally, rhIL-2 and supernatant from ConA-stimulated T lymphocytes enhanced B-lymphocyte proliferation. The stimulatory activity of the T-lymphocyte supernatant could be completely inhibited with a polyclonal anti-rhIL-2 antibody. Finally, polyclonal anti-rhIL-2 antibody, as well as anti-BLV antibody, inhibited spontaneous proliferation of peripheral blood mononuclear cells from persistently lymphocytotic cows, demonstrating that the spontaneous lymphoproliferation characteristic of BLV-induced persistent lymphocytosis is IL-2 dependent and antigen dependent. Collectively, these findings strongly suggest that increased T-lymphocyte expression of IL-2 in BLV-infected cows contributes to development and/or maintenance of persistent B lymphocytosis.

Animals↗

PubMed1975

B-lymphocytosis factor in human plasma.

Patients with acute thermal burns experience an increase of serum immunoglobulins associated with marked B-lymphocytosis during the recovery phase from the burn injury. This study was performed to delineate humoral factors which may induce the B-lymphocytosis in such patients. Plasma samples were obtained serially from 14 adult patients and 14 adult controls. One-half ml of plasma was injected intraperitoneally into C3H/He male mice, and absolute numbers of surface immunoglobulin-bearing cells in the mouse peripheral blood were counted. Fractionation of plasma samples was performed. The biologically active plasma fraction, tentatively termed B-lymphocytosis factor (BLF), was cultured with normal human peripheral blood lymphocytes to determine in vitro lymphocyte transformation. The solubility of 125I-labelled BLF in various organic solvents was examined. Plasma obtained from burned patients induced a marked increase of IgG, IgA, and IgM-bearing cells in the peripheral blood of mice within 3 hours after injection. The B-lymphocytosis activity of normal plasma was not significant. The molecular weight of BLF was estimated to be close to that of ribonuclease A (M.W. 13,400). Transformation of normal human peripheral blood lymphocytes was observed when cultured with BLF. 125I-labelled BLF was not soluble in organic solvents. These data suggest that BLF is not a lipopolysaccharide, and plays a role in regulation of B-lymphocyte levels in burned patients.

Adolescent↗

PubMed1988

Role of T-cell antigens in the cytolytic activities of large granular lymphocytes (LGLs) in patients with LGL lymphocytosis.

By analyzing surface antigens and cytolytic functions of proliferating large granular lymphocytes (LGLs), three types of T cell LGL lymphocytosis were delineated. The first, most commonly encountered type exhibited CD3+4-8+16+, WT31+ phenotype, low or undetectable non-major histocompatibility complex (MHC)-restricted cytotoxicity, and moderate to strong antibody-dependent cellular cytotoxicity (ADCC) and lectin-dependent cellular cytotoxicity (LDCC). Because these LGLs carried T cell antigen receptor (Ti) recognized by WT31 monoclonal antibody (MoAb), and treatment with anti-Ti, anti-CD3 MoAbs and phytohemagglutinin elicited non-MHC-restricted cytotoxicity, they may have developed from populations of in vivo primed cytotoxic T lymphocytes with unknown antigen specificity. The second, rare type of LGL lymphocytosis exhibited CD3+4-8-16+, WT31 phenotype, and strong non-MHC-restricted, ADCC and LDCC cytotoxicities. These cells were probably derived from the lymphocytes of the same phenotype found in small numbers in normal peripheral blood. Because anti-CD3 MoAb inhibited non-MHC-restricted cytotoxicity of the LGLs, a Ti not detected by WT31 MoAb, but putatively present seemed to serve as a specific receptor for target tumor cell recognition. The third type of LGL lymphocytosis showed CD3+4+8-16+, WT31+ phenotype, and lacked cytolytic activities and parallel tubular arrays. These LGLs probably evolved from cells with the same characteristics selectively located in the germinal centers of lymphoid tissues. Taken together, in patients with LGL lymphocytosis, T cell-associated antigens expressed on LGLs were shown to be involved in the regulation of LGL-mediated cytolytic activities. In addition, studies of surface antigens and the effects of MoAbs and lectins on cytolytic activities may be useful in clarifying the normal counterpart of LGLs from which leukemic or reactively proliferating LGLs originate.

Adult↗

PubMed1986

Persistent bronchoalveolar lymphocytosis in asymptomatic farmers.

We previously demonstrated that 14 of 23 asymptomatic dairy farmers with positive precipitins and 5 of 20 without precipitins had an alveolar lymphocytosis (greater than 22%). To verify the outcome of this lymphocytosis, we restudied, 2 or 3 yr later, 27 of these subjects. No subject had had symptoms suggestive of farmer's lung disease either prior to the initial study or between the 2 studies. All were still on their farm. Physical examination and chest roentgenograms were normal for all subjects at both studies. Pulmonary function tests showed a small but significant change in RV (101.8 +/- 20.4% to 118.7 +/- 27.6% of predicted, p less than 0.05) and FVC (98.0 +/- 12.6% to 94.3 +/-9.5%, p less than 0.05), whereas TLC, FEV1, and DLCO showed no changes. Lymphocytes from BAL were still increased in 9 of 12 subjects, whereas 3 had returned to normal; of the 15 subjects with previous normal values, 3 now had an abnormal lavage lymphocytosis. There was no correlation between lung function variations and the percentage of lymphocytes in the previous or the present BAL. We conclude that a bronchoalveolar lymphocytosis is a persistent phenomenon in a large number of asymptomatic dairy farmers, and that this finding is not related to significant disease, at least in the time span studied.

Adult↗

PubMed1974

Bovine leukosis. I. Seasonal influences on lymphocytosis.

The influence of seasons on lymphocytosis status of 321 mature cows from two leukosis herds and a leukosis free control herd was investigated. Animals were bled at three to four month intervals and classifed according to the Göttingen leukosis key as lymphocytosis negative, suspect or positive. The percentage distribution of different hematological classes of animals fluctuated greatly between bleedings, however "persistent lymphocytosis" in animals of leukosis herds was noted to be a constant feature and was not influenced by seasonal variations. The study indicates that 1) multiple samplings are necessary for differentiating between transient and persistent lymphocytosis; 2) caution should be exercised in pooling data from different leukosis herds as these may not be samples from a single leukosis population.

Analysis of Variance↗

PubMed1982

Functional properties of T cells in patients with chronic T gamma lymphocytosis and chronic T cell neoplasia.

The expanded T cell populations of 10 patients with either T gamma lymphocytosis (five patients) or proven chronic T cell malignancy (five patients) were analyzed with respect to functional activity in vitro, including proliferative responses to mitogens, cytotoxic activity (killer [K] and natural killer [NK] cell activity), and regulatory activity on pokeweed mitogen- (PWM) induced immunoglobulin (Ig) synthesis (help and suppression) in comparison with marker phenotypes. In each of the five patients with T gamma lymphocytosis, only one out of three functionally distinct cell types was found: T gamma-K cells, T gamma-S cells, or T gamma-NK/K cells, which mediated K-cell activity, suppressive activity, and both NK and K cell activity, respectively. An expanded T gamma-K cell population was demonstrated in three patients with neutropenia with or without recurrent infections. T gamma-S cells were found in a patient with severe hypogammaglobulinemia, and T gamma-NK/K cells in one patient with asymptomatic lymphocytosis. T gamma-K and T gamma-S cells had a similar surface-marker profile (E+ or E-, Fc gamma+, OKT1-3+4-8+I1-M1-), whereas that of T gamma-NK/K cells was different (E+, Fc gamma+, OKT1-3-4-8-I1+M1+). Longitudinal studies of three untreated patients with T gamma-K lymphocytosis showed that the abnormalities were persistent but not progressive. In contrast, five patients with chronic T cell malignancy (two with T-CLL, two with cutaneous T cell lymphoma [CTCL], and one with T-PLL) all had progressive disease. The neoplastic cells in these cases were E+, Fc gamma-OKT1+4+6- with variable expression of the OKT3 and OKT8 markers. The only functional activity observed in these cells was suppressive activity by OKT3-4+8- cells from a patient with CTCL.

Adult↗

PubMed1997

T-cell lymphocytosis associated with lymphocyte-rich thymoma.

BACKGROUND: Peripheral T-cell lymphocytosis is found on very rare occasions in patients with thymomas. The immunophenotypic features and clonality of the lymphocytes in tumor and peripheral blood now are elucidating this enigmatic phenomenon. METHODS: The author presents what is believed to be the seventh case of peripheral T-cell lymphocytosis associated with thymoma and reviews the previous six cases. The pathology slides of the thymoma were reviewed with a pathologist who confirmed the presence of neoplastic thymic epithelium with cytokeratin stains. Immunophenotyping by flow cytometry was performed at Dianon Systems, Inc., on both the thymoma cells and cells in the peripheral blood. In addition, gene rearrangement analysis was performed on the peripheral lymphocytes using the previously described Southern blot analysis technique with immunoglobulin probes (heavy chain, kappa light chain, and lambda light chain) and T-cell receptor gene probes (beta and gamma chains). RESULTS: Analyses of the T cells within the thymoma and the peripheral blood confirm that the peripheral T cells are both polyclonal and more mature than those populating the thymoma. Clearly the peripheral T cells are not themselves neoplastic, and yet they represent more than physical "spillover" of the immature tumor-related T cells. CONCLUSIONS: Peripheral T-cell lymphocytosis occurs rarely with locally aggressive, lymphocytic thymomas. Although it is clear that these cells are not neoplastic, as they are in other T-cell proliferative disorders, the etiology of this unusual phenomenon remains obscure and may reflect the perturbation of systemic immunoregulation that accompanies thymic neoplasia. It is important to differentiate this condition from T-cell lymphomas or leukemia to treat affected patients appropriately.

Adult↗

PubMed1992

Interleukin-2-induced increase of a monoclonal B-cell lymphocytosis. A novel in vivo interleukin-2 effect?

A 56-year-old man with refractory B-cell lymphocytic non-Hodgkin's lymphoma was treated in a Phase II study with interleukin-2 (IL-2) (Roussel-Uclaf, Romainville, France). The patient had involvement of multiple lymph nodes and medullary and peripheral blood (3.6 x 10(9) monoclonal CD19-positive [CD19+] B-lymphocytes/l). After a 5-day cycle of IL-2 treatment, an eightfold increase of the monoclonal CD19+ population was observed (27 x 10(9) monoclonal CD19+ cells). The lymphocytosis decreased dramatically during the second cycle (days 15 to 19) of IL-2 treatment, resulting in 6 x 10(9)/l peripheral lymphocytes, with 5.5 x 10(9) B-lymphocytes. As soon as day 20, peripheral B-cells again increased considerably, with 32 x 10(9) CD19+ cells/l at day 27. The CD19+ population remained monoclonal as assessed by kappa/lambda cell-surface phenotyping and kappa gene rearrangement evaluation. Kinetics of the monoclonal B-lymphocyte response to IL-2 paralleled the natural killer/lymphokine-activated killer and T-cell response, with a 4-day latency period, suggesting an indirect enhancing effect of IL-2. Before and during IL-2 treatment, peripheral B-lymphocytes never expressed detectable levels of the p55 IL-2 receptor. However, the p75 IL-2 receptor was expressed significantly in the IL-2-responsive monoclonal B-cell population. Tumor necrosis factor alpha, a known (in vitro) B-cell tumor growth factor, reached high serum levels during IL-2 treatment. Response evaluation at day 45 showed stability of the lymph node involvement and the marrow lymphocyte infiltrate. At day 45, peripheral B-cell lymphocytosis was 7.5 x 10(9)/l. To the knowledge of the authors, this is the first report of an in vivo IL-2-induced reversible increase of peripheral monoclonal B-cell lymphocytosis.

B-Lymphocytes↗

PubMed1992

Is persistent polyclonal B lymphocytosis caused by Epstein-Barr virus? A study with polymerase chain reaction and in situ hybridization.

Previous reports of patients with persistent polyclonal B lymphocytosis have found associations with female sex, cigarette smoking, HLA-DR7 phenotype, and moderate elevation of peripheral blood polyclonal B lymphocytes. The presence of binucleated cells and atypical lymphocytes in the peripheral blood of these patients was highly suggestive of a viral infection, such as with the Epstein-Barr virus. We report a 47-year-old asymptomatic woman who was incidentally found to have persistent polyclonal B lymphocytosis and serum IgG against virus capsid antigen (VCA) and Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA) of EBV. The presence of EBV was investigated in the peripheral blood lymphocytes from this patient by in situ hybridization and polymerase chain reaction methods. EBV DNA was demonstrated in the lymphocyte fraction by polymerase chain reaction, and it was further located in lymphoid cells by in situ hybridization. These results indicate that persistent polyclonal B lymphocytosis is strongly associated with EBV.

B-Lymphocytes↗

PubMed1991

Malignant thymoma associated with peripheral T-cell lymphocytosis.

Three cases of peripheral T-cell lymphocytosis associated with thymoma are described. Each patient had a malignant, predominantly lymphocytic thymoma with resolution of lymphocytosis upon treatment of the epithelial neoplasm. These findings suggest that lymphocytosis complicating thymoma is a paraneoplastic phenomenon and is not part of the neoplastic process.

Adult↗

PubMed2002

Abnormal NK cell lymphocytosis detected after splenectomy: association with repeated infections, relapsing neutropenia, and persistent polyclonal B-cell proliferation.

We report the case of a boy with hereditary spherocytosis who presented with mild microcytic hypochromic anemia and recurrent leg ulcers that had been present since childhood. Chronic natural killer (NK) cell and B-cell lymphocytosis was detected 1 year after therapeutic splenectomy during investigation of recurrent episodes of neutropenia and persistent lymphocytosis. NK cells proved to be abnormal at immunophenotyping studies, and B-cells were polyclonal and displayed a normal immunophenotype. Genotypic analysis of T-cell receptor (TCR)-beta and TCR-gamma genes showed a germ-line pattern. The clinical course of this patient was characterized by multiple pulmonary infections and amygdalitis. We discuss the potential roles of persistent immune stimulation due to chronic hemolysis and severe leg ulcers and of splenectomy in the origin of NK cell lymphocytosis and the relationship between NK cells and recurrent infections, relapsing neutropenia, and polyclonal B-cell response.

B-Lymphocytes↗

PubMed2004

Nonobese diabetic CD4 lymphocytosis maps outside the MHC locus on chromosome 17.

Genetic control of homeostasis of peripheral CD4+ lymphocyte levels is incompletely understood. Recent genome scans have linked mouse peripheral CD4 levels to chromosome 17, with strongest linkage to the Ea region. Nonobese diabetic (NOD) mice demonstrate peripheral T-cell lymphocytosis, and previous studies also suggested that the MHC region might control this phenotype. Here we confirm that loci on Chr 17 control NOD peripheral CD4 lymphocytosis. An elevated NOD CD4:CD8 ratio maps to the same region, and we show it is due to increased numbers of CD4+ cells. However, using NOD MHC congenic mice, we demonstrate that the MHC region is excluded, and that NOD peripheral lymphocytosis is controlled by genetic intervals adjacent to the MHC region on Chr 17.

Animals↗

PubMed1975

Persistent lymphocytosis with chromosomal evidence of malignancy.

An inappropriate, sustained and absolute lymphocytosis in a young man was investigated using technics which attempted to define the more detailed features of these cells and their T and B subpopulations. The results of the tests for lymphocyte RFC (E) and complement (EAC) rosette formation, immunofluorescence, in vitro phytohemagglutin (PHA) stimulation and 14C-cyclo-phosphamide binding assays, when evaluated in a combined and interrelated fashion, indicated that the lymphocytosis was mainly but not solely, due to an absolute elevation in circulating T lymphocytes. Moreover, an aneuploid cell line with 47 chromosomes, presumably T cells, also was detected in PHA-stimulated cultures. These data, associated with the patient's anemia, lymphocyte-infiltrated bone marrow, hepatosplenomegaly, pharyngeal lymphoid tumor and the clonal proliferation of lymphocytes bearing an abnormal karyotype, furnish evidence that the lymphocytosis is more than an unremitting leukemoid reaction and is potentially neoplastic. The detection of the chromosomal abnormality at this patient's age and point in disease may make him especially unique in that he could be a clinical prototype for other patients with lymphoreticular tumors which remain undetected at their onset.

Adult↗