Structural and functional properties of the "hairy" cells of leukemic reticuloendotheliosis

"Hairiness" is a Facsimile of Reorganized Cytoskeletons: A Cytopathic Effect of Coxiella burnetii

In 1993, I reported that Coxiella burnetii transforms human B cells into hairy cells (cbHCs), the first hairy cell reported outside of hairy cell leukemia (HCL). Over last few decades, advances in molecular biology have provided evidence supporting that C. burnetii induces hairiness and inhibits the apoptosis of host cells. The present review summarizes new information in support of cbHC. C. burnetii was shown to induce reorganization of the cytoskeleton and to inhibit apoptosis in host cells. Peritoneal B1a cells were found to be permissive for virulent C. burnetii Nine Mile phase I (NMI) strains in mice. C. burnetii severely impaired E-cad expression in circulating cells of Q fever patients. B-cell non-Hodgkin lymphoma was linked to C. burnetii. Mutation of BRAF V600E was pronounced in HCL, but "hairiness" was not linked to the mutation. Risk factors shared among coxiellosis and HCL in humans and animals were reported in patients with Q-fever. Accordingly, I propose that C. burnetii induces reorganization of the cytoskeleton and inhibits apoptosis as cytopathic effects that are not target cell specific. The observed hairiness in cbHC appears to be a fixed image of dynamic nature, and hairy cells in HCL are distinct among lymphoid cells in circulation. As the cytoskeleton plays key roles in maintaining cell structural integrity in health and disease, the pathophysiology of similar cytopathic effects should be addressed in other diseases, such as myopathies, B-cell dyscrasias, and autoimmune syndromes.

Hairy Cell Leukemia: Enzyme-histochemical and Ultrastructural Investigation of one Case

The investigation was carried out on blood smears, bone marrow aspirates, one lymph node biopsy, and the surgically removed spleen of a 53-year-old man with hairy cell leukemia. In the blood smears stained with May-Grünwald-Giemsa, 60 to 70 % of the hairy cells contained tubular inclusions that corresponded to the ribosome-lamella complexes demonstrated at electron microscopy. In blood smears, imprints and cryostatic sections of the lymph node and of the spleen, hairy cells revealed tartrate-resistant acid phosphatase, beta-glucuronidase and adenosine-triphosphatase activity. In the spleen neutral esterase and alkaline phosphatase demonstrated the numerical increase of the histiocytes, which ultrastructurally displayed phagocytic activity. The presence in the spleen of pseudosinuses lined by hairy cells was confirmed by electron microscopy as well as by cytoenzymology.

Splenectomy and treatments of historical interest

Hairy-cell leukaemia (HCL) was initially described as a distinct clinical entity in 1958. Various types of therapy have been evaluated since this initial description and several are currently important only for historical comparison. Hairy-cell leukaemia serves as an example of rapid progress in the development of effective therapeutic strategies. Splenectomy was the first effective treatment because it resulted in an improvement in cytopenias and relief from symptomatic splenomegaly. However, complete remission of the disease was observed only very rarely. Splenectomy was considered an appropriate initial therapy from the 1950s to the early 1980s, although no randomized controlled studies have ever shown improved survival with this approach. In the early 1980s, more effective treatments were identified, initially interferon-alpha, then the purine analogues 2-deoxycoformycin and 2-chlorodeoxyadenosine (2-CdA). These types of therapy have been so effective that most previous treatments are now obsolete. Although the purine analogues result in sustained remissions in the majority of patients, a relatively small percentage of patients relapse and require other types of therapy. Splenectomy may be necessary in some instances. In this chapter the role of splenectomy is reviewed and other types of therapy of historical interest are presented.

The diagnosis of hairy cell leukemia can be established by flow cytometric analysis of peripheral blood, even in patients with low levels of circulating malignant cells

The diagnosis of hairy cell leukemia (HCL) has traditionally been based on microscopic means. Immunophenotypic analysis of peripheral blood by flow cytometry is not widely recognized as a method for diagnosing HCL, perhaps due to the expectation of low yield of neoplastic cells in patients who are characteristically leukopenic. The abnormal coexpression of CD103, CD25, and intense CD11c and CD20 on monotypic, slightly large B-lymphocytes has previously been shown to be highly characteristic of HCL. We wished to determine if this pattern was valuable in the diagnosis of HCL in leukopenic patients with low levels of neoplastic cells in the peripheral blood. The abnormal immunophenotype above was observed in 25 peripheral blood specimens from patients with unexplained cytopenias or suspected lymphoproliferative processes. Ten of the 25 blood samples exhibited this abnormal phenotype in less than 5% of circulating leukocytes (ranging from <1% to 4%). All 10 patients had other manifestations of HCL, including cytopenias (mean white blood cell count, 1.8 x 10(3)/mm(3); hemoglobin, 11.0 gm/dl; platelets, 74 x 10(3)/mm(3)), splenomegaly, and typical bone marrow morphologic changes. Eight of the 10 patients achieved an excellent response to one course of 2-CDA, with significant improvement of cytopenias (mean white blood cell count: 5.3 x 10(3)/mm(3); hemoglobin: 14.4 g/dl; platelets: 181 x 10(3)/mm(3)) and regression of splenomegaly. One patient had a partial response to alpha interferon and a subsequent complete response to 2-CDA, and one died during treatment. In conclusion, flow cytometric immunophenotyping of peripheral blood is capable of detecting low levels of circulating malignant cells in HCL, even in leukopenic patients. As such, it can be a very useful, non-invasive tool in the diagnosis of this disorder.

Vasculitides in hairy cell leukemia

Forty-two cases of vasculitis coincident with hairy cell leukemia (HCL) have been reported, of which 17 had panarteritis nodosa (PAN), 21 had cutaneous leukocytoclastic vasculitis (LCV), and 4 had vessel wall infiltration by hairy cells. PAN generally occurred after the diagnosis of HCL, splenectomy, and infection. HBs antigen was detected in 3 of 12 patients tested, whereas immune complexes were positive in 3 of 4 patients tested. LCV was often preceded by infection and was frequently detected before HCL. Serum immunoglobulin levels were generally elevated when measured. Cryoglobulins, complement, rheumatoid factor, and antinuclear antibodies showed no clear association with vasculitis in HCL. These reports suggest a role for infection and splenectomy as contributing factors to vasculitis.

C-fms protein expression by B-cells, with particular reference to the hairy cells of hairy-cell leukaemia

Although the hairy cells (HCs) of hairy cell leukaemia (HCL) are now thought to be a form of activated B cell, they have long been known to possess certain monocytoid characteristics. Since the proto-oncogene c-fms is a feature of cells of the monocyte/macrophage lineage, we examined HCs for c-fms expression. We found that approximately 80% of peripheral blood HCs expressed the c-fms protein (8/8 cases). Expression of the 150 kD protein by HCs was shown using three different techniques, APAAP, immunofluorescence and immunoprecipitation, using two different antibodies. Other mature B cell lymphoproliferative disorders examined (PLL, CLL and multiple myeloma) did not express c-fms. We also examined the c-fms expression of normal B-cells: both the in vivo activated (low density) fraction of tonsil B cells and tonsil B cells activated in vitro with SAC plus IL-2 expressed the c-fms protein. As in the case of monocytes c-fms expression by HCs was shown to be down regulated by its ligand M-CSF, and by TNF alpha, both caused a decrease in the receptor expression from 80% to 30% and in the intensity of staining from 6 to 3 x 10(4) molecules/cell. However, as for monocytes, GM-CSF treatment of HCs had no effect on the expression of c-fms; alpha IFN also had no effect. M-CSF treatment of HCs also induced phosphorylation of c-fms, and a number of other proteins, on tyrosine. However, M-CSF was unable to induce HC proliferation either alone or in combination with IL-2, IL-4 or IL-6; in addition it had no effect on HC proliferation induced by SAC, anti-mu or TNF alpha. In addition, M-CSF either alone, or in combination with the above cytokines, had no effect on the differentiated state of HCs as shown by both immunoglobulin secretion and surface antigen expression. M-CSF also had no effect on the morphology or long-term survival of HCs in culture. This study therefore demonstrates that both HCs and activated B-cells express c-fms, and that M-CSF binds to and activates its receptor on HCs. Although c-fms and several other proteins were shown to be phosphorylated in response to M-CSF, the functional consequences of this phosphorylation remain unclear.

Hairy cell leukemia cells express CD1a antigen

Five patients with hairy cell leukemia (HCL) were studied. Peripheral blood leukocytes, rosette-forming cells (T) and non-T-cells were stained in immunofluorescence by a panel of monoclonal antibodies to investigate the phenotype of HCL cells (HCLC). In all patients HCLC showed B-lymphocyte phenotype, although they were not stained by antibodies reactive for monocytes, natural killer cells, or T-cells. However, in all instances the large majority of HCLC were unexpectedly stained with an antibody (anti-CD1a) usually detectable only in early thymocytes and on Langerhans cells. This finding was further confirmed by immunoelectron microscopy. This type of ambiguity in the lineage of HCL could imply that HCLC might arise from cells differentiated towards the B-cell lineage, still sustaining an early antigen of a different (T) lineage. These results, moreover, extend the range of the known distribution of the CD1a antigen, which could be useful in diagnosing HCL.

Altered basement membrane structure of the spleen in hairy cell leukaemia. Demonstration of laminin in hairy cells

Changes in five spleens affected by hairy cell leukaemia were characterized using immunohistochemical staining for the basement membrane (BM) components laminin and type IV collagen. The ring fibres had not been totally destroyed, and were well preserved in places. The spaces filled by abnormal blood or hairy cells were assigned to the categories of altered sinus and two types of pseudosinus. In an altered sinus the staining pattern of the ring fibres had gained attenuations and the sinus was sometimes lined by a continuous BM of uneven thickness. The number of altered sinuses was related to the size of the spleen. The pseudosinuses were larger than normal sinuses and usually also larger than altered sinuses. One of the two types seemed to be derived from ruptured Billroth's cords and entailed spaces of irregular size and shape bounded by strips of fibres containing BM proteins. No ring fibres were seen in the wall. The other type of pseudosinus occurred in those spleens where no white pulp remained. These spaces were large, located around arteries and bounded by irregular strips of BM material. In three cases a number of hairy cells could be demonstrated which showed positive staining for laminin either in the surface or in the cytoplasm. Adhesive properties of hairy cells would be conceivable on the basis of the presence of laminin on the surface of the cells.

Alpha-interferon in hairy cell leukaemia: direct effects on hairy cells or indirect cytotoxicity?

This report presents the results of a clinical trial on 53 patients with hairy cell leukaemia using low-dose alpha-interferon as therapy. Improvement of cytopenia and/or bone marrow hairy cell infiltration occurred in all but one patient. Often, blood and bone marrow improvements were dissociated and, after 7 or 13 months of therapy, complete remission was only observed in about 40% of patients. Recurrence of the disease was observed in some cases after cessation of therapy. A summary of the following results is presented: alpha-interferon receptor analysis, oncogene expression, study of the sensitivity of hairy cells to natural killer cells, and the effects of interferon on T-cell receptor gene rearrangement and on the function of T-cell clones. Results are also presented which show that myelofibrosis may be due to a release of platelet derived growth factor. The immunological findings and oncogene expression in 2 patients with a variant form of hairy cell leukaemia for which resistance to therapy was observed are also described. All the results show that interferon acts on hairy cells and are consistent with a direct effect by interferon in the treatment of hairy cell leukaemia.

The arrangement of immunoglobulin and T cell receptor genes in human lymphoproliferative disorders

Immunoglobulin and T cell antigen receptor genes in their germ-line form are organized as discontinuous DNA elements that are joined by recombinations during lymphocyte development. The analysis of immunoglobulin gene structure and arrangement has been of great value in the study of human lymphoid neoplasms. The analysis of rearranged immunoglobulin and T cell receptor genes has been of value in defining the lineage (T or B cell) of neoplasms that were of controversial origin previously, determining the clonality of abnormal lymphocyte proliferations, diagnosing and monitoring the therapy of lymphoid malignancies, determining the state of maturation and the causes for failure of maturation of cells of the B cell series, and providing major insights into the cause of malignant transformation of B and T lymphoid cells. Thus, the application of this molecular genetic approach has great potential for complementing conventional marker analysis, cytogenetics, and histopathology, thus broadening the scientific basis for the classification, diagnosis, and monitoring of the therapy of lymphoid neoplasia.

Hairy cell leukemia

Hairy cell leukemia is a chronic lymphoproliferative disorder that has been recognized as a separate clinical pathologic entity for the last 25 years. After a decade of discussions about the origin of the neoplastic cell, it has now been well established that hairy cells represent a certain, rather mature stage of B-cell differentiation. Evidence for this has been derived from studies using immunophenotyping with monoclonal and polyclonal antibodies, cytochemistry, and immunoglobulin gene rearrangement. For many years, splenectomy was the only therapy of proven value in hairy cell leukemia. For patients who showed insufficient response to the operation, chemotherapy with low-dose alkylating agents was moderately successful, whereas polychemotherapy often resulted in excessive toxicity. More recently, therapy with alpha-interferon has been shown to be very promising, whereas deoxycoformicin may be an attractive alternative. These new advances in immunology and therapy are reviewed.

Hairy cell leukemia: in-vitro proliferation and pseudo-colony formation

In an established double layer clonogenic assay, the PHA-leukocyte feeder colony assay, hairy cell leukemia (HCL) cells formed strong aggregates simulating colonies. After irradiation with 50 Gy, colony formation persisted. Even in a modified colony assay consisting of agar 0.5% overlayered by methylcellulose 0.9%, cell aggregation was still possible due to increasing fluidity of the methylcellulose during the culture period. Time-lapse video recordings confirmed prominent cell motility leading to pseudo-colony formation. Studies with bromodeoxyuridine incorporation showed a low proliferation index (up to 13%) of hairy cells. In conclusion, any assay that facilitates cell motility is unsuitable to study HCL colony growth.

DNA-abnormality in hairy cell leukemia

Spleen and light density peripheral blood leukocytes of 10 hairy cell leukemia (HCL) patients and total leukocytes of one patient and blood donor cells were stained quantitatively for cellular DNA. The DNA content of single cells was measured by flow cytometry (FC) and compared to the DNA content of sheep cells admixed as an internal control. Eight of eleven patients (72 per cent) showed deviations from blood donor DNA content. Two female patients showed increased cellular DNA content, the six male patients had hypodiploid cells. Chromosomal aberrations are therefore likely to exist in the majority of HCL patients. Separation of HCL cells into sheep erythrocyte rosette and non rosette forming cells revealed similar DNA abnormalities in both cell populations, suggesting that the leukemia encompasses cells with B and with T markers.

Alpha-interferon activated cytotoxic lymphocytes in hairy cell leukemia patients: evaluation of cytotoxic events

To further define the mechanisms responsible for the alpha-interferon (alpha-IFN) efficacy in the treatment of hairy cell leukemia (HCL), experiments were carried out to specify the cytotoxic events taking place following this type of therapy. Although an increased natural killer (NK) activity was demonstrable after alpha-IFN treatment, evidence has been provided that hairy cells were not specifically lysed either by fresh autologous/allogenic NK lymphocytes or by lymphokine activated killer (LAK) cells. This property could not be induced in vitro by alpha-IFN or by interleukin-2 (IL-2). Our data favour the hypothesis that the increase of NK cell activity observed following alpha-IFN therapy has not a direct antineoplastic effect but is likely to be of relevance for a non-specific enhancement of the host immune system. In alpha-IFN treated HCL this latter property may account for the better resistance to infections which usually represents the major cause of mortality in these patients.

Use of a panel of monoclonal antibodies for the diagnosis of hairy cell leukaemia. An immunocytochemical study of 36 cases

The phenotype of 36 cases of hairy cell leukaemia has been investigated using a panel of monoclonal antibodies reactive with normal human lymphoid cells and with hairy cells. Staining was performed on frozen sections and/or cell smears by the recently developed APAAP immuno-alkaline phosphatase procedure. In about 90% of cases, neoplastic cells reacted strongly with antibodies against HLA-DR, leucocyte common antigen, B-cells (antibodies B1 and To15), hairy-associated antigens (antibodies KB-90, S-HCL3, HC2) and activated T-lymphocytes (antibodies anti-Tac and Tü69). The phenotype of 10% of cases was clearly different in that the neoplastic cells were negative or only weakly positive for one or more of the antigens recognized by HC2, anti-Tac and Tü69. Antibody HC1 reacted with tumour cells of only 50% of the hairy cell leukaemia cases investigated. Monoclonal antibody Ki-67 (which selectively detects proliferating cells) stained only a low percentage of cells in all but three of the cases studied. The neoplastic cells in all cases were unreactive with monoclonal antibodies anti-Leu1, Tü1, Tü33 and a meshwork of follicular dendritic cells was consistently absent from tissues infiltrated by hairy cells. The immunological phenotype associated with hairy cell leukaemia was not observed in any case of non-Hodgkin's lymphoma, suggesting that it represents a unique type of B-cell neoplasm.

Cell volumes of lymphoblasts in patients with acute lymphocytic leukaemia

Cell volumes of lymphoblasts from 75 cases of acute lymphocytic leukaemia (ALL) and lymphocytes from 33 normal individuals were determined using a Coulter Counter Model H4 Channelyzer. The average mean cell volume (MCV) and the model volume (MV) of lymphoblasts were larger than the MCV and MV of normal lymphocytes (P less than 0.01). In addition, the cell volumes of lymphoblasts from patients with ALL were more heterogeneous than normal lymphocytes. When the volumes of lymphoblasts were compared to the FAB classification, lymphoblasts from cases of L3 were larger than those from L2 and the latter were larger than lymphoblasts from the L1 subtype. When the volumes of lymphoblasts were compared to an immunological classification, lymphoblasts from cases of B cell ALL were larger than those from non-B, non-T and T cell ALL. The volume of lymphoblasts, however, showed no significant predictive value in the determination of complete remission, duration of first remission, or survival.

A comparison of membrane marker phenotypes in hairy-cell leukemia and phorbol-ester induced B-cll cells using monoclonal antibodies

The neoplastic cells from 14 cases of hairy-cell leukemia were investigated in order to determine their membrane phenotype on the basis of their reactivity with a large panel of B-, T-, myeloid/monocytic- and non-lineage restricted monoclonal antibodies. The data were compared to those from monoclonal antibody studies on phorbol-ester (TPA) induced cells from 10 patients with B-type chronic lymphocytic leukemia. The study has so far revealed further evidence for the B-cell nature of hairy-cells leukemia and demonstrates a developmental link between the two cell types, suggesting that hairy-cells represent a more advanced differentiation stage along the B-cell lineage.

Ultrastructural localization of immunoglobulins in hairy cell leukemia

Neoplastic cells from 13 cases of hairy cell leukemia were investigated for immunoglobulin production and lysozyme activity by an electron-immunoperoxidase technique. In 10 cases cytoplasmic immunoglobulins were found, but lysozyme activity was absent in all cases. Immunoglobulins were detected in the perinuclear space and endoplasmic reticulum and at the surface of hairy cells. Of the cases in which immunoglobulins were detected in hairy cells, nine were positive with IgM antiserum and one with IgG antiserum. The immunoglobulins were monoclonal in all cases; six were positive with lambda antiserum and three with kappa antiserum. The class and type of surface immunoglobulins were identical to those of cytoplasmic immunoglobulins in the hairy cells. These results support the conclusion that hairy cells are commonly derived from immunoglobulin-producing B cells at an earlier stage of differentiation than plasma cells.

Further evidence for the B-cell nature of hairy cells. A study using immunostaining of splenic tissue with a wide panel of monoclonal antibodies

Phenotypic characterization of neoplastic cells from 5 patients with hairy cell leukemia (HCL) was performed with 29 monoclonal and 6 polyclonal (anti-Ig) antibodies using immunoperoxidase staining of fresh frozen splenic tissue. Monotypic Ig was expressed in 4 cases, one case was non-expressive. Strong staining was obtained in all cases by monoclonal antibodies (MAs) specific for 3 pan-B-lymphocyte antigens (by anti-B 1, To 15, anti-Leu 12). Five other B-cell related antigens detectable with appropriate MAs (BA-1, anti-B2, DAKO-C3 b R, Tü 1, 38.13) were absent in all cases. The stainings with 13 T-cell associated MAs (OKT 3, OKT 4, anti-Leu 3 a, OKT 6, OKT 8, Tü 68, OKT 10, anti-Lyt 2, Tü 71, OKT 11, anti-Lyt 3, Tü 14, Tü 33) were all negative. Stainings with 4 MAs recognizing myelocytic and/or monocytic antigens (OKM 1, anti-Mo 1, anti-Mo 2, 3 C4) were also negative. We included 14 frozen biopsies with B-type chronic lymphatic leukemia (B-CLL) into our immunohistological study in order to establish phenotypic differences between HCL and B-CLL. Five MAs (Tü 1, anti-Lyt 2, Tü 71, BA-1 and anti-B2) gave consistently negative staining in HCL cases but positive staining in most or all B-CLL cases. The study provides significant evidence for the B-cell nature of HCL and also establishes important phenotypic differences between HCL and B-CLL.

Hairy-cell leukaemia simulating connective tissue disease

A patient is reported, in whom clinical and biochemical evidence of connective tissue disease preceded the diagnosis of hairy-cell leukaemia by at least 2 years. The pathogenetic mechanism(s) responsible for the coexistence of hairy-cell leukaemia with vasculitis and rheumatic disease is discussed. It is proposed that the 2 diseases may share a common predisposing factor, or that the hairy cells may elicit disturbances in immune homeostasis, implying a dysfunction of T suppressor cells. Hairy-cell leukaemia should be considered in the differential diagnosis in cases of unexplained febrile illness associated with pancytopenia and signs of connective tissue disease.

Hairy cell leukemia has a B-cell genotype

The phenotype and, by inference, the cell of origin of some lymphocytic neoplasms has been defined by surface marker studies; however, the precise cellular origin of other neoplasms of the lymphoid system is still unknown. For example, with reference to hairy cell leukemia (HCL), cell marker data has been used in support of a monocytic, a T cell, or a B cell origin. If hairy cell leukemia is a B cell-derived neoplasm, the controversy may be resolved by genotyping the cells, using the rearrangement of immunoglobulin genes as a marker of the B cell nature of the process. Rearrangement of these genes is detected using the Southern blot technique and cloned probes specific for the JH segment of the immunoglobulin genes. In this study, the arrangement of the immunoglobulin genes was analysed in normal tissue, in two accepted B cell lymphomas and in nine cases of hairy cell leukemia. DNA from peripheral blood leukocytes (two patients) and from the spleen (seven patients) revealed a discrete new JH restriction fragment length in the leukocytes of hairy cell leukemia cases. The presence of rearranged restriction fragments is interpreted as evidence of the existence of clonal B cell populations. Three of six samples had rearranged kappa light chain fragments. We conclude that most cases of hairy cell leukemia have a B cell genotype. The use of genotyping has wider application in the analysis of hematological malignancies.

Absence of prolonged benefit of initial leukapheresis therapy for hairy cell leukemia

Four patients with the leukemic phase of hairy cell leukemia were treated with leukapheresis. Two patients failed to respond, and the other two had only transient responses; hematologic improvement lasted one month in one case and four months in the second. The patient with a four-month response underwent a second series of leukapheresis resulting in a response lasting at least 8 months. Two of the four patients subsequently had an adequate trial of prolonged chlorambucil therapy and continued to have a clinical response. We conclude that leukapheresis has little to offer to the majority of hairy cell patients for the long-term management of post-splenectomy patients who develop the leukemic phase. However, an occasional patient can have a transient, and even, rarely, a prolonged response.

The Hemalog D automated differential counter in the diagnosis of hairy cell leukemia

We studied the peripheral blood of 37 patients with hairy cell leukemia (HCL) prior to (n = 24) or following (n = 19) splenectomy, in the Hemalog D multi-channel white cell differential counter, to investigate whether the apparatus could contribute to the (early) diagnosis of this entity and to the differential diagnosis of HCL from atypical hairy cell leukemia (AHCL; n = 9), chronic lymphocytic leukemia (CLL; n = 21) and leukemic non-Hodgkin lymphoma of low-grade malignancy (LNHL; n = 19). HCL showed almost invariably monocytopenia, neutropenia and an increased percentage of LUC, with a rather typical picture of the X-Y display of the peroxidase channel. The percentage of hairy cells closely correlated with the percentage of the LUC from the Hemalog D. Discriminant analysis using several parameters of the Hemalog D differential count resulted in a complete separation of HCL from CLL, and a fair, although not complete, distinction of HCL from AHCL and LNHL. It was impossible to discriminate between AHCL and LNHL. The most important discriminating (single or combined) parameters were the absolute monocyte count, the TWBC and the absolute neutrophil number. It is concluded that the Hemalog D is a valuable tool in the (early) diagnosis of HCL and in the discrimination between HCL and other leukemic lymphoproliferative disorders.

Hairy cell leukemia: absence of natural killer activity and of interleukin 1 release in OKM-1+ spleen hairy cells

Phenotypic characterization by monoclonal antibodies of spleen cells obtained from three spleens involved by hairy cell leukemia (about 90% of cells with intracytoplasmic tartrate-resistant acid phosphatase) indicated that the hairy cells are OKT-3-, OKM-1+, and OKIa1+. Neoplastic cells obtained from two lymph nodes involved by B-cell lymphoma were found to be OKT-3-, OKM-1-, and OKIa1+. Functional characterization of the hairy cells present in the spleen indicated that they lack NK activity and do not release Interleukin 1. In fact, spleen hairy cells were not lytic against K-562 tumor cells in a short-term 51Cr-release assay and did not release Interleukin 1 in culture supernatants even after LPS stimulation. In normal individuals, both these cell functions are expressed by subpopulations of OKM-1+ cells.

Generalized monocyte deficiency in leukaemic reticuloendotheliosis

Examination of the blood of 40 patients with leukaemic reticuloendotheliosis (LRE) revealed a drastic reduction in monocyte numbers (mean 74/microliter) when compared to a normal group of 33 (mean 442/microliter). Repeated blood studies in 8 LRE patients were made over periods of 2 months to 5 years and monocytopenia was observed to be a persistent phenomenon. Similarly, tissues from 29 patients showed an overall decrease in numbers of monocytes/ histiocytes when compared with those of 73 control subjects. Skin window examinations in all 11 patients so studied showed marked reduction or absence of monocyte response to inflammation. 2 exceptional cases to this trend are noted. In one, circulating monocyte levels remained normal over a 14-month period while examinations of blood and marrow in this case showed few hairy cells. In another case, severe and persistent monocyte deficiency was noted during a 2-year period of unsuccessful treatment. When he eventually responded to low dose chlorambucil and his Hb rose from 40-140 g/l and WBC became normal, the number of circulating monocytes also became normal.

Biopsy findings in malignant histiocytosis presenting as lethal midline granuloma

Nasal biopsy findings in malignant histiocytosis presenting clinically as lethal midline granuloma are characterised by necrosis and infiltration of atypical histiocytic cells with a diffuse positive reaction for non-specific esterase. This cellular character was common to midline malignant reticulosis, and midline malignant reticulosis and malignant histiocytosis are thought to be the same disease. Patterns of histiocytic infiltration in the nasal lesions of 19 cases are reported in this paper. Polymorphic and monomorphic patterns were observed in 11 and four cases respectively, on the initial biopsy, but subsequently the infiltrates frequently became monomorphic on serial biopsy. The reverse was not observed. Surface marker and cytochemical studies showed the true histiocytic nature of the proliferating cells, and necropsy findings justified the diagnosis of malignant histiocytosis.

Granulomatous infections complicating hairy cell leukemia

Of 14 patients with hairy cell leukemia (HCL), four developed opportunistic granulomatous infections: blastomycosis, coccidioidomycosis and two Mycobacterium kansasii. The former two pathogens have not been reported with HCL, while M. kansasii infections appear to be common. While most reviews stress susceptibility to pyogenic bacteria and the predisposing role of iatrogenic factors, three of our patients were infected prior to any therapy. Thus, disease-related factors predispose to these granulomatous infections. Granulocytopenia and monocytopenia were present; the latter was not often corrected by splenectomy. There was impaired granuloma formation, with all infectious lesions appearing histologically as focal microabscesses containing few macrophages. Awareness of the frequency of opportunistic intracellular infections with early consideration of invasive diagnostic procedures to establish specific etiologic diagnosis may greatly prolong survival for many HCL patients.

Splenic alterations in hairy-cell leukemia: II. an electron microscopic study

Spleen from nine patients with hairy-cell leukemia (HCL) were studied for ultrastructural alterations. In all cases, hairy cells with typical ultrastructural characteristics were observed within splenic cords and sinuses. Hairy cells had numerous cytoplasmic processes that interdigitated with cytoplasmic processes of other hairy cells. Hairy cells also adhered to sinus endothelial cells and ring fibers and protruded into spaces between endothelial cells. Some normal sinuses were filled with aggregated hairy cells. Other sinuses appeared dilated. Many sinuses were lined by hairy cells that covered thinned endothelial cells and ring fibers. In these abnormal sinuses, endothelial cells were decreased and many appeared injured. The splenic cords were expanded by an infiltration of hairy cells and by large blood-filled spaces. These findings suggest that hairy cells adhere to many cell surfaces, produce endothelial cell injury and death, and impede the venous flow of blood in the spleen. All of the factors appear to influence the formation of the abnormal splenic sinuses and the blood-filled spaces that characterize HCL.

Chronic monocytic leukemia in adults

Clinical, hematologic, and histologic material from five patients with chronic monocytic leukemia is analyzed, and the literature is reviewed on 28 patients either reported as having this disease or referenced as such in subsequent publications. Patients with chronic monocytic leukemia have a characteristic clinical course. All have splenomegaly of uncertain etiology, and initial hematologic evaluation usually shows anemia with normal leukocyte and differential counts. One of the authors' patients had slight monocytosis at presentation. In the four patients for whom presplenectomy bone marrow smears were available for review, there was no detectable increase in the number of monocytes. The patients developed monocytosis, usually with accompanying leukocytosis, at intervals ranging from 3.5 to 24 months after splenectomy. In all patients, there was a corresponding increase in the numbers of mature monocytes in the bone marrow. Survival times from the detection of monocytosis ranged from five to eight months. Of the 28 cases reported in the literature, only two were considered by the authors of this study to have the characteristics of chronic monocytic leukemia, and of these, only one had features identical to those reported in the present series. The remainder represent a variety of hematologic disorders including chronic myelomonocytic leukemia, acute leukemia, histiomonocytic proliferations that cannot be sub-classified, and cases in which the data are insufficient for analysis. The differential diagnosis includes chronic myelomonocytic leukemia, chronic malignant histiocytosis, and hairy cell leukemia. In chronic monocytic leukemia, in contrast to hairy cell leukemia, splenectomy does not appear to be beneficial. Although chronic monocytic leukemia is an extremely rare disease, it is a distinct hematologic entity that appears to have a characteristic clinical course.

Lymphocytic lymphoma simulating hairy cell leukemia: a consideration of reliable and unreliable diagnostic features

Morphologic, immunologic and functional characteristics of an unusual poorly differentiated diffuse lymphocytic lymphoma closely resembling hairy cell leukemia are presented and the diagnostic features of the latter disease are reviewed. The malignant cells morphologically resembled hairy cells at the light as well as electron microscopic level. They had surface characteristics of both T and B lymphocytes, were phagocytic, and adhered to glass. The spleen was smooth and resembled that seen in hairy cell leukemia. Although there was a predilection for the red pulp of the spleen, there was a lack of characteristic pseudosinus formation, and areas of predominantly white pulp involvement considered characteristic of lymphocytic lymphoma were found after extensive examination.

A hemalog D analysis of chronic lymphocytic leukaemia and other lymphoproliferative disorders affecting the blood

A correlative clinical and Hemalog D study of 80 cases of chronic lymphocytic leukaemia (CLL) was performed and the results compared with those in other lymphoproliferative disorders affecting the blood (eight cases of hairy-cell leukaemia, HCL; three cases of prolymphocytic leukaemia, PLL: two cases of lymphoplasmacytoid proliferation, LPP; and one case of Sézary's syndrome, SS). In CLL the mean percentage and absolute counts of large unstained cells (LUC) were 8.7% and 6.2 x 109/1 (6200/mm3), and the percentage of LUCs was not substantially affected by treatment; there was no correlation between LUCs and Rai clinical stage. SS and LPP were characterised by a similar percentage of LUCs, but both HCL and PLL were distinguished by a higher mean percentage of LUCs. Stage IV CLL was associated with monocytopenia, but other stages of CLL, PLL, LPP, and SS showed no consistent reduction of absolute numbers of non-lymphoid cell types. In contrast, HCL was characterised by a consistent absolute neutropenia and monocytopenia which distinguished its Hemalog D profile from that of PLL.

Hairy cell leukemia: establishment of a cell line and its characteristics

A hairy cell leukemia (HCL) line, ZK-H, was established from peripheral blood of a 69-year-old male patient. The ZK-H cells and the patient's original hairy cells shared the same surface properties; both possessed membrane-bound IgG with kappa light chains and villous surface structures. The ZK-H line carried Epstein-Barr virus (EBV)-determined nuclear antigen, but the patient's fresh leukemic cells lacked this antigen. Morphologically, the ZK-H cells appeared lymphoblastoid and more primitive than the preculture cells. The ZK-H line had a hyperdiploid chromosome constitution of 47 and trisomy no. 2. The presence of membrane-bound immunoglobulin and of B-cell tropic EBV in this cell line provides further evidence for the B-cell nature of HCL in this patient

Non-Hodgkin's lymphomas in leukemic phase: clinicopathologic correlations

A leukemic phase occurred in 30 (14 percent) of 214 patients with non-Hodgkin's lymphoma. To determine the significance of peripheral blood involvement in each type of NHL, patients were subdivided according to a modified Rappaport classification. Each histologic subtype presented a homogeneous clinical picture which differed from that seen in other histologic subtypes. Of particular note was the recognition of two distinctive cytologic and clinical subtypes within the category of nodular lymphoma, poorly differentiated lymphocytic lymphoma (NPDL). In one subtype, the predominant cells had cytologic features akin to those of lymphoblasts. In these cases, although the interval to peripheral blood involvement was variable, the median leukemic survival was only two months. In contrast in conventional NPDL the median leukemic survival was 43+ months, and peripheral blood involvement did not appear to exert an independent effect on prognosis. In diffuse large cell lymphomas the median leukemic survival was 0.5 months, with peripheral blood involvement appearing as a terminal event associated with unresponsive disease in multiple sites. The recognition of adult lymphoblastic lymphoma as a clinicopathologic entity with a high risk of leukemic conversion, 100 percent in this study, is also confirmed.

Diffuse large cell lymphomas (reticulum cell sarcomas, histiocytic lymphomas). Correlation of morphologic features with functional markers

Electron microscopic findings in 15 cases of diffuse large cell lymphoma were correlated with other morphologic features, surface immunotype and cytoplasmic immunoglobulin content. Immunologically, the cases were: B cell, 8; null, 4; T cell, 2; and H cell (true histiocytic), 1. Ultrastructurally, all B cell and three null lymphomas were characterized by an abundance of polyribosomes and segments of rough endoplasmic reticulum. Concentric rough endoplasmic reticulum was observed in 4 cases of B cell lymphoma containing cytoplasmic immunoglobulin and in a null lymphoma. In 1 case of B cell lymphoma, the diastase-sensitive, periodic-acid-Schiff-positive cytoplasm showed evidence of widely dispersed monoparticulate glycogen granules. The two T cell lymphomas contained hyperlobulated or single round nuclei, and abundant smooth to rough endoplasmic reticulum. One null lymphoma appeared to share the ultrastructural features of T cell convoluted nuclei and the cytoplasmic organelles of myeloid precursor cells. The H cell lymphoma had features of monocytic-macrophagic differentiation. The large cell lymphomas, a morphologically and functionally heterogeneous group, were represented predominantly in this series by neoplasms with follicular center cells or early plasma cells.

Surface immunoglobulin, lectin-induced cap formation, and phagocytic function in five patients with the leukemic phase of hairy cell leukemia

Hairy cells from 5 patients with greater than 25% hairy cells in the peripheral blood (4 had greater than 45% hairy cells and white blood cell counts (WBC) greater than 10,000/mm3) were studied for surface immunoglobulin (SIg) presence and distribution by two methods, for lectin-induced cap formation, and for phagocytosis of zymosan. Hairy cells from all 5 cases were found to have distinct monoclonal patterns, 2 Gk, 1 MDk, 1 Dk, and 1 GMDk, as well as cap formation with SIg. All 5 cases showed distinct lectin-induced cap formation in a percentage of cells similar to the percentage of hairy cells, and 2 of the 5 patients had hairy cells which phagocytosed zymosan. These findings contrasted with the malignant cells from 4 patients with CLL, which had monoclonal SIg but no SIg cap formation and no significant percentage of lectin-induced cap formation. Cells from 2 cases of T cell lymphomas had no SIg and no lectin-induced cap formation as did cells from 2 cases of non-lymphocytic leukemia. Hairy cells not only appear to have SIg cap formation similar to some B-lymphocytes, which in some patients also phagocytose zymosan, but also demonstrate strong lectin-induced cap formation.

Cell volume studies in B-cell leukaemia

Leucocyte volume histograms were obtained in 12 cases of B-chronic lymphocytic leukaemia (B-CLL), two cases of B-prolymphocytic leukaemia (B-PLL) and two cases of hairy-cell leukaemia (HCL) by means of a Coulter model ZBl linked to a channelyser. Visual examination of the histograms showed differences between the cases which were confirmed by measurement of the modal volume (MV) and the sigma value (SD of log-volume). The MV of the cells in B-CLL ranged from 153.8 to 244.2 fl (mean 198.24 fl) and was lower than the MV in the cases of HCL (427.5 and 465.6 fl). One case of B-PLL had cells with an MV within the B-CLL range while in the other the MV was greater (317.9 fl). The histogram in one of two cases of B-CLL in 'prolymphocytoid' transformation showed a relatively high sigma value, thus suggesting heterogeneity in cell size. The volume histogram is a simple method of sizing the predominant cell in the peripheral blood in lympho-proliferative disorders and permits an objective comparison between cell sizes in different diseases.

Studies of lymphocyte proliferation in hairy cell leukaemia: activity in mixed lymphocyte reaction and responses to mitogens

Subpopulations of splenic lymphocytes from patients with hair cell leukaemia (HCL) were compared with similar subpopulations of lymphocytes from reference individuals for their ability to respond to mitogens and to participate in allogenic and autologous mixed lymphocyte reactions. T cell enriched subpopulations were obtained by double passage of mononuclear cells through mylon wool columns. Non-T cell subpopulations were collected by eluting adherent cells from nylon wool columns and by incubating them with sheep erythrocytes followed by density gradient centrifugation. Unfractionated mononuclear cells, T enriched and non-T subpopulations were compared. Enriched T cell subpopulations from HCL and reference patients responded similarly to allogeneic antigens and phytohaemagglutinin. Splenic non-T cells from reference patients produced a stronger stimulus in the allogeneic mixed lymphocyte reaction than did the unfractionated or the T enriched cells. In contrast, the non-T subpopulations from patients with HCL produced a reduced response compared to that of reference splenic cells when mixed with allogeneic lymphocytes. In addition, non-T cells from HCL patients failed to respond to pokeweed mitogen. Neither reference nor HCL splenic cells produced a significant response in the autologous mixed lymphocyte reactions. The data suggest that splenic non-T cells from patients with HCL either suppress the stimulatory capacity of normal B lymphocytes or fail to stimulate allogeneic lymphocytes in the mixed lymphocyte reactions.

Phagocytosis in acute leukemia

The phagocytic potential of leukemic cells in various types of acute leukemia was studied. Cases included lymphoblastic leukemia, myeloblastic leukemia, myelomonocytic leukemia, monocytic leukemia, progranulocytic leukemia, blast transformation of chronic myelocytic leukemia, and unclassified leukemias. Cytochemical stains were used as an aid in classification. These included Sudan black B, naphthol AS-D chloroacetate esterase, alpha-naphthyl butyrate esterase, acid phosphatase, and periodic acid-Schiff. Phagocytosis was evaluated after incubation of leukemic cells with Candida albicans. Rare phogocytic activity was seen in lymphoblastic leukemia, unclassified leukemias, blast crises in chronic myelocytic leukemia, and progranulocytic leukemia. Myeloblastic leukemias were feebly phagocytic. Myelomonocytic leukemia and monocytic leukemia both exhibited marked phagocytosis which distinguished them from the other acute leukemias. Myelomonocytic leukemia could be differentiated from acute monocytic leukemia by its greater phagocytic capacity.

Hairy-cell leukaemia: an immunoperoxidase study of paraffin-embedded tissues

Paraffin sections of a variety of tissues from 12 patients with typical hairy-cell leukaemia (HCL) were stained for immunoglobulin heavy and light chains by the peroxidase-antiperoxidase (PAP) technique. Plasma cells were frequent, particularly in a lymph node from a severely infected patient. The reactive nature of the plasma cells of HCL was suggested by the fact that there was no restriction of light-chain expression, although viable hairy cells were shown to express monoclonal surface immunoglobulin. This, together with the absence by both light and electron microscopy of forms intermediate between hairy cells and plasma cells and the lack of ribosome-lamella complexes in the plasma cells, suggested that hairy cells do not differentiate into plasma cells. Although hairy cells are known to contain immunoglobulin, this was not demonstrable in hairy cells in the paraffin-embedded tissue. The PAP technique was also useful for demonstrating abundant splenic macrophages in HCL.

Hairy-cell leukaemia with polyarteritis nodosa

In four patients a systemic vasculitis similar to polyarteritis nodosa developed within 2 years of the onset of hairy-cell leukaemia. Arteriographic studies in two patients revealed microaneurysms, and biopsy specimens in three patients revealed a vasculitis affecting medium-sized vessels. Blood neutrophilia and neutrophilic vascular infiltrate were absent. One patient had circulating immune complexes. Two patients responded to corticosteroids alone, one required cyclophosphamide as well as steroids, and one improved without chemotherapy. The association of vasculitis with hairy-cell leukaemia may provide insight into the pathogenesis of arteritis.

Phagocytic potential of hairy cells

The hairy-cells (HC) of 10 patients with hairy-cell leukaemia were studied with several techniques to evaluate their phagocytic potential. Mononuclear cells from normal donors and from patients with acute monocytic leukaemia served as controls. Light microscopically HC seemed to have ingested bacteria or latex particles. Treatment of the cells with lysostaphin, an enzyme that kills extracellular Staphylococcus aureus, showed that almost all 'ingested' bacteria were extracellular. Lanthanum nitrate, added during the fixation procedure for electron microscopy, stained both the outer cell membrane and the membranes of the 'phagosomes' of the HC, also indicating that the 'ingested' particles were extracellular. HC showed no increased oxygen consumption on exposure to bacteria in the presence of serum. Furthermore, HC showed no lysozyme or peroxidase activity, whereas non-specific esterase activity was much weaker than in monocytes. These findings, which show that HC are essentially non-phagocytic, constitute strong evidence against a monocytic origin of the malignant cells of hairy-cell leukaemia.

Cell-surface characteristics of hairy cell leukemia in seven patients

Surface marker studies were performed on "hairy cells" from 7 patients with hairy cell leukemia (HCL). Using sensitive analytic techniques including specific antisera and Fluorescence Activated Cell Sorter (FACS-1), further definition of the abnormal cell was achieved. Four different antisera were used in infestigating the cell surface characteristics of these patients: anti-p23,30, an antiserum reactive with B cells and a subset of monocytes, anti-311, which reacts only with T cells, pepsin digested anti-F(ab')2 which reacts with B cells only and pepsin digested anti-lysozyme reactive with monocytes and myeloid cells, but not with B or T cells. In all cases strong reactivity was observed with anti-p23,30 and anti-F(ab')2, but no reactivity with anti-311. Five out of the seven cases were reactive with anti-lysozyme in a pattern similar to normal monocytes. Furthermore, when cells were separated according to binding to anti-p23,30, anti-F(ab')2 and anti-lysozyme and in two cases, according to cell size, the majority of reactivity and large cells were "hairy" when examined under microscopy. In contrast, the small and nonreactive (dull cells) appeared as normal mature lymphocytes. Thus, our data supports the view that HCL cells bear in most cases B cell and monocytic membrane markers.

Hairy cell leukemia: differences in phagocytic capacity of cells in vitro

Hairy cells from eight patients with hairy cell leukemia were evaluated with both light and transmission electron microscopy for their capacity to phagocytose zymosan, latex, staphylococcus aureus, and pseudomonas aeruginosa. In two patients, there was no phagocytosis of any of these substances; cells from three patients phagocytosed only latex; two, all except pseudomonas; and one, all 4 substances. Hairy cells became relatively smooth while in culture with staphylococcus, but no surface changes were noted during incubation with the other substances. Of the eight patients studied, one died of pseudomonas pneumonia and sepsis; pseudomonas was the only substance which her hairy cells did not phagocytose. The one patient whose hairy cells phagocytosed all 4 test substances developed a disseminated Mycobacterium intracellulare infection; culture of his hairy cells with this atypical myocbacterium showed no phagocytosis. Hairy cells have different phagocytic capabilities from patient to patient, and the evaluation of these capabilities in vitro might provide early identification of potential infectious complications.