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

"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.

Molecular insight into the biology and clinical course of hairy cell leukemia utilizing immunoglobulin gene analysis

The B cell receptor (BCR) is the functional distinguishing unit that defines any B cell. Immunoglobulin gene (IG) status is preserved in the neoplastic B cell clone and can provide an indicator of the maturation stage reached by the B cell prior to transformation. In hairy cell leukemia (HCL), several pieces of data from IG analysis provide clear hints regarding the cell of origin and the ongoing selective interactions of the tumor BCR with environmental stimuli. HCLs have variable levels of IG somatic mutations, and continue somatic mutations at low levels as well as IG class switching after transformation. More recent data also show the occurrence of selective events in the light chain of the BCR, suggesting a dominant role for IG status in the pathogenesis of HCL. Moreover, it has recently emerged that an unmutated status of the HCL IG can be associated with failure to respond to cladribine, genetic abnormalities indicative of poor outcome, and aggressive disease. These observations suggest that IG analysis may have biological and prognostic relevance in HCL and merits further characterization.

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. Durability of response to splenectomy in 26 patients and treatment of relapse with androgens in six patients

Twenty-three of 26 patients with hairy cell leukemia evaluable for response to splenectomy had significant improvement in anemia, thrombocytopenia, and/or neutropenia. Eight of the 23 had a recurrence of cytopenia after a median response duration of 4 to 5 months (range, 1-22). The remaining 15 patients did not have a recurrence of cytopenia at 20 months median follow-up (range, 1-76). Six patients with postsplenectomy cytopenia were given androgenic steroids. Two of the six had an improvement in anemia and thrombocytopenia, and a third patient had an improvement in neutropenia. It was concluded that, although most patients with hairy cell leukemia have initial improvement in cytopenia with splenectomy, a significant number of them either fail to respond or have recurrent cytopenia after initial response to splenectomy. A trial of androgenic steroids is a reasonable therapeutic option in these patients. Alternative therapies are reviewed and recommendations made.

Rapid morphological and substratum adherence response by hairy cell and other human leukemic cells to phorbol ester tumor promoters

Human leukemic cells, maintained in tissue culture, responded differentially following exposure to the phorbol ester tumor promoter 12-0-tetradecanoylphorbol-13-acetate (TPA). Short-term (0-2 h) TPA treatment of hairy cell leukemic cells (of presumed B-lymphocytic origin) resulted in the attachment of 5-100% of cells (depending on % leukemic mononuclear cells) to the culture dish and extension of long processes. Similar changes were also observed with cells from acute myelogenous, acute prolymphocytic and some acute monomyelocytic leukemic patients. Related non-promoters such as phorbol and 4-alpha-phorbol-12, 13-didecanoate, had no effect. In contrast, both chronic and acute lymphocytic, chronic myelogenous and acute promyelocytic leukemic cells showed no response to TPA over this short time period. Neither the adherence nor morphological changes were blocked by inhibitors of protein synthesis (cycloheximide) or glycosylation (tunicamycin), but the process formation was sensitive to inhibitors of microtubule formation such as colchicine. The effect was not reversible by TPA removal, and exposure to TPA for only 5 min resulted in a complete adherence and morphological induction within 60 min.

Autologous red blood cell and platelet engulfment in hairy cell leukemia

Seven cases of hairy cell leukemia (leukemic reticulo-endotheliosis) are presented in which peripheral blood or splenic hairy cells or both were identified engulfing autologous red blood cells or platelets. In 3 patients, approximately 5-15% of their peripheral blood hairy cells were engulfing red cells and platelets. In 2 patients, intercellular junctions were present between processes of hairy cells and were similar to processes occasionally seen connecting Langerhans cells to each other. Also, parallel tubular arrays were identified in the cytoplasm of hairy cells from 2 other patients. We conclude that autologous red blood cell and platelet engulfment is a common finding in hairy cell leukemia.

Surface immunoglobulins on hairy cells of 55 patients with hairy cell leukemia

Surface immunoglobulins (SIg) were determined on peripheral blood samples from 55 patients with hairy cell leukemia (HCL) and on hairy cells from spleen preparations of 14 of these 55 patients. The patterns of SIg for HCL was compared to the patterns on peripheral blood leukemic cells from 39 patients with chronic lymphocytic leukemia (CLL) and 15 patients with poorly differentiated lymphocytic (PDL) lymphoma. Of the 55 HCL patients, 42 could be scored for individual heavy and light chains; 16 had only IgG, 14 had two or three heavy chains, 7 had only IgD, and 5 cases had no SIg and were E-rosette negative. This pattern was different from the B-cell pattern in CLL and PDL where there were few cases of IgG alone (5%) and many cases of IgM alone (50%). Surface marker profile did not correlate with survival in any of the sub-groups tested. HCL appears to be a B-cell lymphoproliferative disease in greater than 90% of cases; many combinations of heavy chains with only a single light chain can be demonstrated.