Myelomonocytic Leukemia Research Articles

T-helper- and accessory-cell-independent cytotoxic responses to human tumor cells transfected with a B7 retroviral vector.

As a means to increase the immunogenicity of tumor cells, we have developed a retroviral vector to transfect human B7, a molecule capable of delivering co-stimulatory signals to T cells. Three different tumors, a melanoma, an ovarian carcinoma and a myelomonocytic leukemia, were transfected with high efficiency. When compared for their capacity to stimulate allogeneic T cells, B7+ but not B7- tumor cells were able to stimulate strong proliferative and cytotoxic responses. The effector CTL generated recognised B7+ and B7- cells as well as untransfected tumor cells, indicating that B7 is required in the inductive but not the effector phase of the response. Remarkably, B7+ tumor cells were able to induce cytotoxic responses both by CD4-depleted and by CD8-purified T cells, demonstrating that expression of B7 is at the same time necessary and sufficient to induce a cytotoxic response in the absence of T-helper cells and accessory cells.

Detection of chromosome 11q23 involving translocations by pulsed field gel electrophoresis

Translocations involving chromosome band 11q23 are associated with acute lymphocytic and myelomonocytic leukemias with poor clinical prognosis. Pulsed-field gel electrophoresis (PFGE) was used to characterize the breakpoint region that has been mapped within a 300-kb fragment between the genes CD3G and PBGD. Using CD3G as a marker on SfuI-restricted DNA separated by PFGE, we detected a rearrangement involving 11q23 in the cell line B1 with a t(4;11) and in the leukemic cells of two patients, one with a t(2;11) and one with a t(11;19). In comparison, lymphoblastoid cell lines established from normal peripheral blood lymphocytes of these two patients had a normal karyotype and showed germline configuration, thus excluding RFL polymorphisms. Digestion of DNA with BssHII or SalI showed heterogeneity of 11q23 involving breakpoints. A rearrangement in the t(4;11) containing lymphoma cell line Karpas422 was seen only with the chromosome 4 probe KIT on SalI-digested DNA. PFGE is a reliable method for the mapping and detection of complex breakpoint regions. The breakpoints on 11q23 involve different introns of the highly spliced HRX/ALL-1/MLL gene.

Constitutive Overexpression of the c-fos Gene in Radiation-Induced Granulocytic Leukemia in Mice

Among various myeloid leukemias which were induced by X rays in C3H/He mice (Seki et al., Radiat. Res. 127, 146-149, 1991), the three most frequent types were analyzed for myeloperoxidase, c-myc, c-myb, and c-fos mRNAs. It was shown by in situ hybridization that all the component cells were positive for myeloperoxidase mRNA in granulocytic leukemia, whereas only half the cells were positive in myelomonocytic leukemia and none in monocytic leukemia. Granulocytic leukemia was also characterized by a persistently heightened expression of c-fos, while the other two types of leukemia showed negligibly low expression of the c-fos message. By contrast, both c-myc and c-myb were expressed to a similar extent in all three types of leukemia. When fresh granulocytic leukemia cells were transferred to culture in a medium containing 0.5% fetal calf serum, c-fos mRNA was decreased rapidly during incubation. The decay of c-fos mRNA was inhibited by cycloheximide markedly but was not changed significantly by actinomycin D. In the culture containing 10% fetal calf serum, the rate of decay of c-fos mRNA was slowed down significantly. Addition of dibutyryl cyclic AMP rapidly restored the c-fos expression and kept it elevated for at least 2 h in the cultured granulocytic leukemia cells. Phorbol ester (TPA) and calcium ionophore A23187 also caused a rapid but transient c-fos expression. A transient c-fos expression was inducible by TPA in the other two types of leukemia cells and in the granulocytic leukemia cells. The results suggest that the persistent expression of c-fos is distinguished from its transient expression and is characteristic for granulocytic leukemia cells as it is for normal mature granulocytes.

Altered expression of the human retinoblastoma gene in monocytic leukaemias.

Inactivation of the retinoblastoma growth suppressor gene (RB) is responsible for the development of retinoblastomas and occurs frequently in osteosarcomas and small cell lung carcinoma. Knowledge about the involvement of RB in the pathogenesis of myeloid leukaemias is still scarce. In this study we looked at the expression of the retinoblastoma gene product (p105) in 20 primary myelomonocytic and monoblastic leukaemias by Western blotting and immunocytochemistry using the anti-p105-monoclonal antibody PMG3-245. We found absence of or barely detectable levels of p105 in 11 patients (55%). Absence of or low levels of p105 were correlated with a higher leucocyte count at presentation (133 x 10(9)/l v 83 x 10(9)/l) and with the occurrence of extramedullary leukaemia (8/10 v 2/10). We conclude that abnormal expression of RB with absence of p105 or strongly reduced p105 levels occurs frequently in myelomonocytic and monoblastic leukaemias and that this may be correlated with a more malignant course of the disease.

マクロファージと凝固・線溶異常

We examined the role of monocyte-macrophages (MO/MAC) in hemostatic disorder. Plasma cytokine levels, such as interleukin-1β (IL-1β) and tumor necrosis factor (TNF) were higher in patients with hemophagocytic syndrome (HPS) associated severe hemostatic disorder and organ failure. These cytokine levels were also increased in patients with disseminated intravascular coagulation (DIC), suggesting that the activation of MO/MAC is involved in the pathogenesis of hemostatic disorder.Tissue factor (TF) activity and plasminogen activator (PA) activity in leukemic cells were significantly higher in DIC patients than in non DIC patients. PA inhibitor-II antigen in leukemic cells was highest in acute monocytic or myelomonocytic leukemia (AMoL/AMMoL). Those patients showed hypercoagulant-hypofibrinolytic state and organ failure, suggesting that PAT-II played an important role in the hemostatic abnormalities.In the study of cultured MO/MAC, IL-1β elevated TF activity and PAI-II antigen in MO/MAC lysate, their culture medium significantly elevated TF and PAI-I production of human umbilical vein endothelial cells (HUVEC). Lipoproteins also had the capacity to elevate TF production of MO/MAC.These finding suggested that MO/MAC play a very important role in thrombogenesis and organ failure by secretion of cytokines and/or expression of TF and PAI-II.

Inversion of chromosome 16 and bone marrow eosinophilia in a myelomonocytic transformation of chronic myeloid leukemia

We report a case of chronic myeloid leukemia (CML) in myelomonocytic transformation associated with bone marrow (BM) eosinophilia. At diagnosis, all BM cells showed a Ph chromosome. At the time of blastic phase, more than 50% of Ph + cells had a pericentric inversion of chromosome 16, inv(16)(p13q22). This case confirms that blastic transformation of CML can involve any committed progenitor, and myelomonocytic leukemia with BM eosinophilia is specifically associated with rearrangement of chromosome 16 at band p13 and q22.

Increased Tyrosine Protein Kinase Activity in Hairy Cell and Monocytic Leukemias

Tyrosine protein kinases (TPK) help regulate cellular growth and differentiation. Several proto-oncogenes encode for protein products with associated tyrosine kinase activity. An assay for TPK activity was performed in cell extracts using a synthetic peptide substrate and [32P] adenosine triphosphate (ATP). TPK activity was elevated in K-562 cells, which possess an amplified c-abl oncogene, compared to normal blood mononuclear cells (K-562 = 9.37 +/- 1.72 [mean +/- standard deviation] pmol ATP/10(6) cells/min; normal = 1.14 +/- 0.46, p less than 0.01). TPK activity was measured in peripheral blood mononuclear cells from patients with hairy cell leukemia (HCL), myelomonocytic leukemia (MOL), acute myeloblastic leukemia (AML), and chronic lymphocytic leukemia (CLL). In patients with clinically active disease, elevated TPK activity was measured in mononuclear cells from five HCL patients (range 3.76-24.15) and from seven MOL patients. These elevated levels appeared to parallel disease activity, as low levels of TPK activity were measured in patients with inactive (treated) disease. Low levels of TPK were measured in mononuclear cells from active AML and CLL patients. Elevated TPK levels in patients with HCL and MOL may reflect the overexpression of a proto-oncogene or increased growth factor activity in immature or rapidly dividing leukemic cells. Serial TPK levels in HCL and MOL patients correlated with change in disease activity.

Immunohistochemical characterization of Ki-M6 monoclonal antibody in Bouin-fixed, paraffin-embedded sections of normal and neoplastic human tissues

A monoclonal antibody (Ki-M6) against the CD 68 antigen, which labels cells of the monocyte/macrophage system, was tested on Bouin-fixed, paraffin-embedded samples of normal, reactive and neoplastic tissues by an avidin-biotin-peroxidase complex method, with the aim of establishing its value in diagnostic pathology. In normal human tissues, Ki-M6 reactivity was confined to the so-called resident macrophages populating normal organs under physiological conditions. Moreover, restricted reactivity against cells of macrophage lineage was observed in reactive and inflammatory lesions. Granulocytes, monocyte/macrophage-related immune accessory cells, and other analysed normal tissue structures did not reveal any reactivity. Ki-M6 was strongly reactive with the cases of benign (4/4) and malignant (15/15) fibrous histiocytomas, in addition to the true histiocytic lymphomas (3/3). Cases of granular cell tumour (2/3) showed strong reactivity with Ki-M6, whereas only few immunoreactive cells, with weak staining, were seen in the other Ki-M6-positive neoplasms [neurofibroma (3/3), benign schwannoma (1/2), ganglioneuroma (1/1), malignant schwannoma (5/9), melanoma (9/28), dermatofibrosarcoma protuberans (1/1), myelomonocytic leukaemia (3/3)]. Among the epithelial malignancies tested (47 cases), Ki-M6 was positive only in renal cell carcinoma (11/14). Malignant lymphomas of the Hodgkin (56 cases) and non-Hodgkin type (67 cases) were uniformly non-reactive. From these data, Ki-M6 appears to be an excellent marker of monocyte/macrophage-related cells and appears to be a reliable indicator for fibrous histiocytomas and true histiocytic malignancies. The availability of this additional antibody capable of staining routinely processed tissue is of practical interest.

Concurrent Eosinophilic Fasciitis and Cutaneous T-Cell Lymphoma

Eosinophilic fasciitis has been reported to precede hematologic malignant neoplasms such as myelomonocytic leukemia, lymphocytic leukemia, and Hodgkin's lymphoma. In this case study, eosinophilic fasciitis occurred concurrently with cutaneous T-cell lymphoma (mycosis fungoides). The clinical diagnosis of eosinophilic fasciitis was based on painful sclerodermatous lesions on the extremities and trunk without acrosclerosis. There was histologic confirmation with edema and lymphocytic inflammation in the superficial muscular fascia and dermis. Deposition of immune reactants was found in the fascia and dermis. In addition, peripheral eosinophilia and circulating immune complexes were detected. The diagnosis of cutaneous T-cell lymphoma (mycosis fungoides) was based on extensive erythematous cutaneous plaques, dermal and epidermal lymphocytic atypia, loss of pan-T-cell immunologic markers, and a cutaneous lesional T-cell receptor beta-chain rearrangement by Southern blot analysis. Eosinophilic fasciitis may occur as a paraneoplastic syndrome associated with hematologic malignant neoplasms, including mycosis fungoides. Cytokines or lymphokines released by activated immunocytes, either malignant leukocytes or normal leukocytes reacting to malignant cells, may be responsible for the eosinophilia and sclerosis seen in these associated hematologic malignant neoplasms.

Flow Cytometric Analysis of Terminal Deoxynucleotidyl Transferase

Terminal deoxynucleotidyl transferase (TdT) is a useful marker for lymphoid precursor cells. In this study, the authors used flow cytometry (FCM) to analyze TdT expression in human hematopoietic malignancies. Cells were fixed in 0.5% formaldehyde, briefly exposed to nonionic detergent, and subsequently labeled with mouse monoclonal anti-TdT antibodies followed by fluorescein-conjugated antimouse IgG and propidium iodide (PI), which was used for the simultaneous analysis of DNA content. Cells from 20 of 22 acute lymphoblastic leukemias (ALL), 4 of 7 mixed lineage leukemias, 2 of 21 acute myeloid and myelomonocytic leukemias, 1 of 2 chronic myeloid leukemias in blast crisis, 1 lymphoblastic lymphoma, and 1 thymoma were TdT positive. Cells from 13 nonlymphoblastic lymphomas, 3 myelodysplastic bone marrows, and peripheral blood mononuclear cells from 29 normal individuals were negative. An excellent correlation was seen between this assay, the conventional slide immunofluorescence technique, and an enzyme immunoassay method. The FCM assay detected as few as 2% blasts in mixing experiments of TdT-containing leukemic cells with normal peripheral lymphocytes. Furthermore, the combined analysis of TdT and DNA allowed the recognition of aneuploid TdT positive cells in four cases of ALL. The high sensitivity, the quantitative information obtained, and the capability of simultaneously analyzing DNA content make this method of TdT analysis more valuable than conventional techniques.

Plasmacytoid T-Zone Cell Proliferation in a Patient with Chronic Myelomonocytic Leukemia

The term "plasmacytoid T-zone cells" has been used to describe distinctive cells that occur in clusters in the paracortex of some reactive lymph nodes. Recently, tumorous proliferations of these cells have been described in several patients with myelomonocytic leukemias. Neither the nature of these cells nor their relationship to myeloid leukemia has been conclusively established. We report the case of a 64-year-old woman with chronic myelomonocytic leukemia who developed lymphadenopathy that proved to be due to tumorous accumulation of plasmacytoid T-zone cells in the interfollicular regions of the lymph nodes. She underwent splenectomy because of symptomatic splenomegaly; the resected spleen also contained aggregates of plasmacytoid T-zone cells, in addition to extramedullary hematopoiesis. On treatment with busulphan and prednisone, the lymphadenopathy resolved and did not recur. The patient died 7 years later with blast transformation of her myelomonocytic leukemia and no recurrence of lymphadenopathy. The aggregates of plasmacytoid T-zone cells were architecturally and cytologically distinct from the leukemic infiltrates of myeloid cells in the spleen, and there was no evidence of differentiation of these cells into myeloid or monocytic cells. A panel of monoclonal antibodies on paraffin sections revealed no lineage-specific T- or B-cell markers (UCHL1-, L26-), and the plasmacytoid cells were positive for CD68 (KP1) and L60 (CD43), as well as faintly positive for 4KB5 (CD45RA) and MB1 (CD45R). They did not stain with antibodies to myeloid lineage antigens CD15, lysozyme, or myeloperoxidase. The combination of clinical, morphologic, and immunologic features of plasmacytoid T-zone cells in this case suggests that these cells may be of monocytic lineage but are not direct precursors of mature monocytic or granulocytic cells, and may not be part of the neoplastic clone in patients with myelomonocytic leukemia.

Esterase Isoenzyme Profiles in Acute and Chronic Leukemias

Using isoelectric focusing (IEF) a number of carboxylic esterase isoenzymes (EC 3.1.1.1) with isoelectric points between pH 4.5-8.0 can be separated. One particular isoenzyme with an isoelectric point at about pH 6.0, the Mono-band, can be selectively and completely inhibited by sodium fluoride; this isoenzyme comprises a number of closely related subcomponents and may appear in more than one band on the gel. We analyzed the expression of typical esterase isoenzyme patterns in cells from a large panel of leukemias which were tested under identical conditions by IEF on horizontal thin-layer polyacrylamide gels with an ampholyte of pH 2-11. The 442 cases of acute and chronic myeloid and lymphoid leukemia (AML/AMMoL, CML/CMML, ALL, CLL) were classified according to clinical, morpho-cytochemical and immunophenotyping criteria. While bands between pH 4.5-5.5 appeared not to be specific for lineage or stage of differentiation, isoenzymes between pH 6.6-7.7 provided information on the type of leukemia involved. Seven typical isoenzyme patterns termed Mono1/Mono2 (fo monocyte-associated), My1/My2 (myeloid), Lym1/Lym2 (lymphoid) and Und (undifferentiated) could be discerned. Lym and Und patterns are characterized by fewer bands with a weaker staining intensity than Mono and My patterns. Nearly all cases of lymphoid leukemias (acute and chronic) expressed only Lym or Und esterase isoenzyme patterns, but no Mono or My patterns. Cases of acute or chronic myeloid and (myelo)monocytic leukemia showed strong isoenzyme staining displaying predominantly Mono or My isoenzyme patterns. The isoenzyme patterns found in CML in lymphoid or myeloid blast crisis corresponded to those seen in the respective acute leukemias, ALL or AML. The Mono-band was found in most cases of leukemias with monocytic elements (AMMoL 80%, CML 44%, CMML 100%), in the occasional case of CML-myeloid blast crisis or AML, but in none of the cases of ALL or CLL. This isoenzyme is a distinctive, specific marker for leukemias of monocytic origin and is of discriminatory value for the differentiation of monocytic from non-monocytic leukemia variants. Esterase isoenzyme profiles can give additional evidence on the origin and stage of differentiation of leukemic cells.

Blood findings in generalized mastocytosis: evidence of frequent simultaneous occurrence of myeloproliferative disorders

Blood findings in 61 cases of generalized mastocytosis (GM) were evaluated. The cases were divided into two major variants: Systemic mastocytosis (SM; n = 34) with urticaria pigmentosa-like skin lesions, and malignant mastocytosis (MM; n = 27), without skin involvement. The following results were obtained: (1) Significant differences between MM and SM were found in the main haematological parameters (erythrocyte, platelet and leucocyte counts and haemoglobin level); normal values were found in 16 of the SM cases, but never in MM. (2) The main pathological findings were: in SM, anaemia (9/34) and leucocytosis (5/34); and in MM, leucocytosis (19/27), monocytosis (14/27), eosinophilia (12/27), bicytopenia (12/27, mostly anaemia with thrombocytopenia), basophilia (10/27) and isolated anaemia (7/27). (3) The major finding was a significant difference between MM and SM in the incidence of myeloproliferative disorders (MPD), myelodysplasia and mast cell leukaemia (MCL): these disorders occurred in 23 (92%) MM patients, but only in two (6%) SM patients (P less than 0.001). The four instances of MCL and two of myelodysplasia all occurred with MM. Of the 19 cases of MPD, six (SM, 1; MM, 5) were acute variants (acute myeloid and myelomonocytic leukaemias) and 13 (SM, 1; MM, 12) were chronic variants. No case of malignant lymphoma was noted. (4) The blood picture in 10 of 13 chronic MPD cases represented an atypical chronic myeloid leukaemia for which the preliminary descriptive term 'mastocytosis-associated MPD' is proposed. (5) A survey of 103 published cases (SM, 77; MM, 26) yielded similar findings, including a high incidence of MPD and MCL in MM. These findings add further weight to the argument for recognizing SM and MM as two separate entities.

Tumor cell implantation with the use of Gelaspon ® gelatin sponge disc

Myelomonocytic leukemia (My) mesoblastic nephroma (Ne) and hepatocellular carcinoma (He) cells were implanted under the renal capsule of F344, Long-Evans (LE) and BDIX rats. Gelaspon ® sponge discs were used in the implantation procedure, which were resorbed within a few days. The tumor cells, which were located on the surface of these discs could then attach themselves to the renal capsule and thus grow. There was a correlation between the number of tumor cells and the difference between the two kidney masses. The correlation was linear between 10 4 and 10 6 cells, thus the method proved to be a simple, fast and quantitative model in experimental cancer prevention and therapy.

Definition of an acquired 11q deletion in a tumorigenic human monocytic cell line

Romitt i et al. (1986) repor ted the cytogenetic characterization of four monocytic cell lines established f rom bone marrow samples of patients with hematopoiet ic diseases other than leukemia. The cell line that they referred to as case 2 FR. B/S was f rom a patient with cyclic neutropenia who later developed an acute myelomonocyt ic leukemia. The line was shown to have acquired an interstitial deletion of the long arm of chromosome 11 after 59 passages in vitro, and at this passage it was able to induce tumors in nude mice. The breakpoints were localized in bands 11q21 and 11@4. This region of chromosome 11 is frequently involved in structural rearrangements in cases of acute myeloid leukemia (M4-M5 types), acute lymphocytic leukemia, and B-cell diffuse lymphoma. Yunis et al. (1989) repor ted a patient with an acute myelomonocyt ic leukemia with evidence of amplification of eleven genes mapped at 11q23---~qter and discussed the gene order and the relevance of this region in hematological malignancies. Since the cell line seemed to have lost the band 11q23, we were interested in investigating the possible presence, loss, or transposition of the oncogene ets-1, mapped at band 11q23.3 (Rovigatti et al. 1986), for a possible relation to the tumorigenicity. A Southern blot analysis with an h-c-ets-l-specific probe (5.4-kb EcoR1 genomic f ragment kindly provided by Dr. D. Stehelin) showed a normal gene dosage and absence of any detectable rear rangement (Carrozza, unpublished), and so we per formed in situ hybridization with the same probe on chromosome preparat ions at the 134th passage, when the deletion was still present in all cells. The analysis of the distribution of the autoradiographic grains showed a positive signal present both on the normal and on the deleted chromosome 11 (Fig. 1 a). This result led us to reconsider the breakpoints of the deletion, and we reanalyzed the cell line at the 142nd passage with a high-resolution banding technique (Dutrillaux and Peguignot 1981). The banding pat terns revealed an interstitial deletion with loss only of the band 11q14 and breakpoints at l lq14.1 and 11q14.3 (Fig. lb ) .

The human metallothionein gene cluster is not disrupted in myelomonocytic leukemia

The human metallothionein gene complex on chromosome 16 has been remapped to 16q13 using high-resolution in situ hybridization. The complex is not disrupted by the rearrangement breakpoint on the long arm of chromosome 16 in patients with myelomonocytic leukemia with abnormal eosinophils, as had been previously reported. The locus order on 16q is cen- MT-FRA16B-D16S4-inversion breakpoint- HP-tel.

The human class I MHC gene HLA-F is expressed in lymphocytes

Genomic and cDNA clones encoding a human, non-classical class I gene, Dew3, have been isolated. The complete coding sequence has been determined. The sequence is capable of directing expression of a protein with high sequence homology to HLA-A,B,C molecules but with a shortened cytoplasmic tail. Sequence comparisons demonstrate that this gene is from a separate locus to the 'classical' HLA-A,B,C and 'non-classical' HLA-E and HLA-G loci. Dew3 is equally distantly related to all of these previously described, functional class I genes. It is, however, extremely homologous to a third 'non-classical' gene, HLA-5.4, and to the chimpanzee gene, Ch28. The RNA species it transcribes is shorter than that of the classical genes, due to an altered acceptor splice site which results in the loss of exon 7. The transcription of Dew3 RNA shows a unique pattern of tissue distribution, being expressed in B cell lines and peripheral blood lymphocytes and absent from T cell lines, fibroblasts and a myelomonocytic leukaemia. A Dew3 protein product was detected after transfection into a human EBV-transformed B cell line but was located intracellularly. The HLA-5.4 gene has been recently designated HLA-F. The Dew3 and X5.1 clones thus represent two new alleles of the HLA-F locus in man. Sequence comparison with its chimpanzee homologue suggests that selective pressure for conservation of amino acid sequence is still maintained at this locus.

前白血病期に一過性の単球による皮膚浸潤を呈したAcute Myelomonocytic Leukemia

前白血病期に一過性の単球による皮膚浸潤を呈したAcute Myelomonocytic Leukemia

Development of nonthymic lymphomas in thymectomized NFC mice exposed to split-dose X-irradiation.

Split-dose X-irradiation efficiently induced Thy-1-positive thymic lymphomas (80%) in intact NFS mice within 12 months after irradiation. A high incidence (67%) of nonthymic lymphomas and leukemias was observed in the thymectomized NFS mice. Development of nonthymic lymphomas and leukemias in these mice started about 2 months later than that of thymic lymphomas and increased significantly 10 months onward after the last irradiation, when the development of thymic lymphomas in intact mice had already come to an end. These nonthymic lymphomas and leukemias involved predominantly the spleen and the mesenteric lymph nodes. Twelve out of 18 lymphomas and leukemias were examined immunocytologically. All of these tumors except one were diagnosed as lymphomas including one plasmacytoma. One case was diagnosed as myelomonocytic leukemia because the leukemic cells were highly positive for nonspecific esterase and negative for chrolacetate esterase. All lymphomas tested were negative for thy-1.2, and five of them expressed surface immunoglobulins. From these results, nonthymic lymphomas developed in thymectomized and X-irradiated NFS mice were classified as B-cell lymphomas probably including non-T/non-B cell lymphomas. Present findings demonstrated that a low incidence of nonthymic lymphomas in intact NFS mice exposed to split-dose X-irradiation should be ascribed to a longer latency since most of the mice died of thymic lymphomas prior to the development of overt nonthymic lymphomas.

Eosinophilic fasciitis: Clinical spectrum and therapeutic response in 52 cases

The clinical course of 52 cases with eosinophilic fasciitis observed at the Mayo Clinic has been described. Cutaneous changes included pitting edema, peau d'orange, and induration, and may affect virtually any body surface area. In addition, localized morphea was present in 15 cases. Arthritis was observed in 21 patients; 29 patients had flexion contractures and 12 had carpal tunnel syndrome. Associated hematologic diseases were found in five patients; thrombocytopenia in two, myeloproliferative disorder in one, myelomonocytic leukemia in one, and chronic lymphocytic leukemia in one. Peripheral blood eosinophilia was noted in 33 of 52 patients, hypergammaglobulinemia was noted in 17 of 49, and elevated sedimentation rate was noted in 15 of 52. Nonspecific EMG changes were seen in 11 of 15 patients. None had clinical involvement of the kidneys, lungs, or heart. No significant association between any HLA-A, -B, or -DR and eosinophilic fasciitis was seen. Prednisone and hydroxychloroquine seemed equally beneficial in treatment; however, some cases showed spontaneous recovery, making evaluation of therapeutic efficacy difficult. Relapses occurred in some cases.