Gordon Starkebaum

The central role of chromatin in autoimmune responses to histones and DNA in systemic lupus erythematosus.

To gain insight into the mechanisms of autoantibody induction, sera from 40 patients with systemic lupus erythematosus (SLE) were tested by ELISAs for antibody binding to denatured individual histones, native histone-histone complexes, histone-DNA subnucleosome complexes, three forms of chromatin, and DNA. Whole chromatin was the most reactive substrate, with 88% of the patients positive. By chi-square analysis, only the presence of anti-(H2A-H2B), anti-[(H2A-H2B)-DNA], and antichromatin were correlated with kidney disease measured by proteinuria > 0.5 g/d. SLE patients could be divided into two groups based on their antibody-binding pattern to the above substrates. Antibodies from about half of the patients reacted with chromatin and the (H2A-H2B)-DNA subnucleosome complex but displayed very low or no reactivity with native DNA or the (H3-H4)2-DNA subnucleosome complex. An additional third of the patients had antibody reactivity to chromatin, as well as to both subnucleosome structures and DNA. Strikingly, all sera that bound to any of the components of chromatin also bound to whole chromatin, and adsorption with chromatin removed 85-100% of reactivity to (H2A-H2B)-DNA, (H3-H4)2-DNA, and native DNA. Individual sera often bound to several different epitopes on chromatin, with some epitopes requiring quaternary protein-DNA interactions. These results are consistent with chromatin being a potent immunogenic stimulus in SLE. Taken together with previous studies, we suggest that antibody activity to the (H2A-H2B)-DNA component signals the initial breakdown of immune tolerance whereas responses to (H3-H4)2-DNA and native DNA reflect subsequent global loss of tolerance to chromatin.

Leukemia of large granular lymphocytes: association with clonal chromosomal abnormalities and autoimmune neutropenia, thrombocytopenia, and hemolytic anemia

Three patients had leukocytosis of large granular lymphocytes and chronic neutropenia. Clonal chromosomal abnormalities (trisomy 8 and trisomy 14) and lymphocytic infiltration of splenic red pulp, hepatic sinusoids, and bone marrow indicated the neoplastic nature of the large granular lymphocytes. Demonstration of a T3+, T8+, HNK-1 + phenotype and low natural killer cell activity that was augmented by interferon treatment showed the leukemic cells to be immature natural killer cells. Multiple autoantibodies were present and included rheumatoid factor and antinuclear, antineutrophil, antiplatelet, and antierythrocyte antibodies, suggesting a defect of B-cell immunoregulation. In addition, in-vitro studies showed impaired suppression of immunoglobulin biosynthesis by abnormal cells from one patient. Antineutrophil antibodies and absence of direct cell-mediated inhibition of granulocyte-macrophage colony formation supported a humoral immune mechanism for the neutropenia. In these patients the syndrome of splenomegaly, multiple autoantibodies with neutropenia, and lymphocytosis of large granular lymphocytes is due to a neoplastic proliferation of immature natural killer cells.

Large granular lymphocyte leukemia. Report of 38 cases and review of the literature.

LGL leukemia results from a chronic, clonal proliferation of LGL. Chronic neutropenia with recurrent bacterial infection and splenomegaly are common clinical manifestations. Rheumatoid arthritis coexists in some of these patients, who thus resemble patients with Felty syndrome. Other hematologic abnormalities that may occur include pure red-cell aplasia and adult-onset cyclic neutropenia. Lymphoid infiltration of bone marrow, splenic red pulp cords, and hepatic sinusoids is characteristic; lymph node and skin involvement are rare. Multiple serologic abnormalities are frequently present, including positive tests for rheumatoid factor and/or antinuclear antibody, polyclonal hypergammaglobulinemia, and circulating immune complexes. Antineutrophil and antiplatelet antibodies are often present. Leukemic LGL exhibit phenotypic heterogeneity; the most common phenotype in our patients is CD2+, CD3+, CD8+, HNK-1+, CD16-. Despite markedly increased numbers of LGL, functional activity of the cells is usually decreased. The mechanism of cytopenias is uncertain: in pure red-cell aplasia, it appears to be due to suppressive effect on erythropoiesis by abnormal LGL, but in patients with chronic neutropenia it may be antibody-mediated. Although most patients appear to have a relatively benign clinical course, mortality from infections and progressive lymphoproliferation is substantial. Optimal therapy remains undefined. Some preliminary evidence suggests that LGL leukemia may be associated with infection with a retrovirus similar to HTLV-I. Although relatively rare, LGL leukemia is of interest because a better understanding of this disease process may contribute to our knowledge of autoimmune diseases, the immunoregulatory functions of LGL, and the mechanisms controlling normal hematopoiesis.

Pancytopenia Associated With Low Dose Pulse Methotrexate in the Treatment of Rheumatoid Arthritis

Low dose pulse MTX was associated with the development of pancytopenia in six patients with RA. Two patients died. Factors implicated in the occurrence of this complication were renal impairment in five patients, medication errors by two patients, preexisting marrow injury from occult alcoholism in one patient, and an apparent idiosyncratic reaction to the drug in another. Medication errors were associated with the use of five or more medications, and the unusual schedule of administration of low dose MTX may also have been contributory. From a consideration of the clinical pharmacokinetics of MTX, we suggest other factors that may predispose to the occurrence of marrow toxicity: the presence of hypoalbuminemia, interactions between MTX and other protein bound or weakly acidic drugs, and the repetitive dosing schedule of low dose MTX. Based on our experience, patients with impaired renal function (creatinine greater than or equal to 2.0 mg/dL) should not receive MTX. Renal function should be monitored regularly during treatment with MTX, and blood counts should be observed carefully if a new drug is added or substituted. A 5 mg test dose of MTX before initiating weekly therapy may identify patients with severe hypersensitivity to the drug. The potential risks of using MTX in a patient unwilling to accept blood products should be acknowledged and discussed with the patient. Furthermore, we recommend the use of leucovorin if pancytopenia occurs, even if low or undetectable serum levels of MTX are present.

Veterans Using and Uninsured Veterans Not Using Veterans Affairs (VA) Health Care

Objectives. The objectives of this study were to: (1) examine veteran reliance on health services provided by the Veterans Health Administration (VA), (2) describe the characteristics of veterans who receive VA care, and (3) report rates of uninsurance among veterans and characteristics of uninsured veterans. Methods. The authors analyzed data from the 2000 Behavioral Risk Factor Surveillance System. Using bivariate and multivariate analyses, the association of veterans demographic characteristics, health insurance coverage, and use of VA services were examined. Veterans not reporting VA coverage and having no other source of health insurance were considered uninsured. Results. Among veteran respondents, 6.2% reported receiving all of their health care at the VA, 6.9% reported receiving some of their health care at the VA, and 86.9% did not use VA health care. Poor, less-educated, and minority veterans were more likely to receive all of their health care at the VA. Veterans younger than age 65 who utilized the VA for all of their health care also reported coverage with either private insurance (42.6%) or Medicare (36.3%). Of the veterans younger than age 65, 8.6% (population estimate: 1.3 million individuals) were uninsured. Uninsured veterans were less likely to be able to afford a doctor or see a doctor within the last year. Conclusions. Veterans who utilized the VA for all of their health care were more likely to be from disadvantaged groups. A large number of veterans who could use VA services were uninsured. They should be targeted for VA enrollment given the detrimental clinical effects of being uninsured.

Polyarthritis and Neutropenia Associated with Circulating Large Granular Lymphocytes

Five patients with polyarthritis and neutropenia had numerous circulating large granular lymphocytes with a phenotype attributed to immature natural killer cells. All five had splenomegaly and recurrent infections. Arthritis was most prominent at the wrists and hands, and all patients were considered to have atypical cases of Feltys syndrome. Antinuclear antibodies, rheumatoid factor, antineutrophil antibodies, and immune complexes were detected in most patients. Bone marrow biopsies revealed a maturation arrest at the myelocyte stage and lymphoid infiltrates. Large lymphocytes with azurophilic cytoplasmic granules were found on peripheral blood smears and showed a characteristic reactivity pattern with monoclonal antibodies suggesting a natural killer cell lineage. Peripheral blood mononuclear cells showed less than normal natural killer activity against K562 target cells. Increased numbers of large granular lymphocytes with a phenotype of immature natural killer cells may be important in the pathogenesis of neutropenia, humoral immune disturbances, and synovitis in a subset of patients with Feltys syndrome.

PROTOTYPICAL HTLV-I/II INFECTION IS RARE IN LGL LEUKEMIA

The etiology of LGL leukemia is not known; however, we recently detected HTLV-II in a patient with LGL leukemia. In this study, we found that sera from 6 of 28 patients with LGL leukemia were positive for HTLV-I/II using a whole virus ELISA; moreover, the ELISA-negative sera were near the positive cut-off value. Therefore, we performed additional studies on these sera using commercially available assays which can confirm and distinguish HTLV-I from HTLV-II infection. Serum from only one patient was confirmed positive using conventional criteria (HTLV-II+). Sera from 25 patients (89%) had indeterminate reactivity on Western blot assays. Of these, sera from 21 (84%) reacted to gag protein p24; 12 (48%) reacted with recombinant env protein p21e, and 10 (40%) reacted with both. We could not detect HTLV-I/II pol or pX gene sequences in these patients using polymerase chain reaction analyses, with the exception of the HTLV-II-infected patient described previously. These data show that most patients with LGL leukemia are not infected with prototypical HTLV-I or HTLV-II. The frequent reactivity of patient sera to HTLV-I/II gag protein p24 and to env protein p21e, however, suggests that a deleted or variant form of HTLV-I/II may be associated with LGL leukemia.

Chronic lymphocytosis with neutropenia: Evidence for a novel, abnormal T-cell population associated with antibody-mediated neutrophil destruction☆

A 67-year-old man with stable chronic neutropenia, lymphocytosis, multiple auto-antibodies, and recurring infections was studied in order to characterize the abnormal lymphocytes and the mechanism of neutropenia. One-half of the circulating mononuclear leukocytes were large granular lymphocytes that did not rosette with sheep erythrocytes and did not have surface immunoglobulin or receptors for C3 or IgG Fc. Virtually all of the mononuclear leukocytes, however, reacted with three monoclonal antibodies specific for mature T lymphocytes--OKT3, 3A1, and 12.1--the latter with a bimodal pattern on FACS analysis. The nonadherent, non-E-rosetting lymphocytes consisted of a homogeneous population of T cells with a novel phenotype: 3A1+, OKT3+, OKT8+, Ia+, 12.1+, OKT4-, 9.6-, 10.2-, Fc gamma receptor-. The abnormal phenotype of these cells suggested that they may have developed clonally. In spite of their OKT8+ phenotype, these lymphocytes were functionally abnormal, since they did not suppress B-cell immunoglobulin production in vitro. A humoral immune mechanism of neutropenia was indicated by increased levels of neutrophil-reactive IgG and in vivo kinetic studies with autologous neutrophils demonstrating shortened intravascular survival. The granulocyte turnover was normal, however, suggesting a blunted marrow response to the neutropenia. Corroborating the kinetic data, in vitro cultures of the patients blood and marrow cells showed reduced numbers of granulocytic progenitors (CFU-C). Neither blood lymphocytes nor serum from the patient suppressed growth of allogeneic CFU-C nor did removal of OKT8+ cells from the marrow increase CFU-C expression. Thus, the disorder in this patient is characterized by proliferation of abnormal OKT8+ lymphocytes with impaired suppressor function. Our findings suggest that the neutropenia was due to anti-neutrophil autoantibodies that may have resulted from abnormal T-cell immunoregulation.

Humoral Immune Abnormalities in T-Cell Large Granular Lymphocyte Leukemia

The prevalence of humoral immune dysfunction has not been defined in a large series of patients with T-cell large granular lymphocyte leukemia (T-LGL) confirmed to be clonal by T-cell receptor analysis. Therefore we evaluated the presence of multiple autoantibodies in 27 patients with this disease. Humoral immune abnormalities included: rheumatoid factor (RF) (15/27 patients), antinuclear antibody (ANA) (13/27 patients), polyclonal hypergammaglobulinemia (15/24 patients), elevated serum immunoglobulins (17/26 patients), immune complex formation (18/25 patients), elevated beta-2 microglobulin (13/18 patients) and neutrophil-reactive IgG (18/20 patients). Disease manifestations in these patients were due to complications of cytopenia or autoimmune abnormalities. Infection was a common finding (21/27 patients) and likely reflected their neutropenia. Rheumatoid arthritis (11/27 patients), anemia (12/27 patients) and thrombocytopenia (10/27 patients) were less common but still frequently observed. This study demonstrates the presence of multiple autoantibodies in a large series of patients with documented clonal T-LGL proliferations.