Kikuchi-Fujimoto disease involving retroperitoneal lymph nodes: An uncommon presentation

Kikuchi-Fujimoto disease is a self-limited disease of unknown etiology that is clinically defined by fevers accompanied by tender posterior cervical lymphadenopathy. It often presents acutely or sub-acutely, and due to its non-specific features, the differential diagnosis is broad and includes infectious, autoimmune, and malignant causes. Although cases of extra-cervical disease are not uncommon, involvement of retroperitoneal lymph nodes has only rarely been reported. Here, we describe a patient with Kikuchi-Fujimoto disease who presented with fever of unknown origin, abdominal pain, and enlarged hypermetabolic retroperitoneal lymph nodes.

Acquired Inhibitors of Factor V

The clinical and laboratory data on the 12 patients with an acquired inhibitor to factor V have been reviewed. The degree of clinical bleeding in these patients varied from none to severe, and in most patients the inhibitor was transient. The combination of a markedly prolonged partial thromboplastin time and Quick prothrombin time and failure of normal plasma to correct these tests, in the presence of a normal thrombin and prothrombin and proconvertin time, seems to be pathognomonic for a factor V inhibitor. The inhibitors have physicochemical properties of immunoglobulins and a few have been characterized as polyclonal IgG antibodies or a mixture of IgM and IgG antibodies. The etiology and pathophysiologic mechanism of their development is unknown, but there seems to be a close relationship to major surgery. When tested with inhibitor plasma, the plasmas from 9 patients with hereditary factor V deficiency from 7 unrelated families did not contain factor V antibody-neutralizing material.

Endothelial-Dependent Fibrinolysis in Subjects with the Lupus Anticoagulant and Thrombosis

To investigate the hypothesis that diminished endothelial fibrinolytic activity contributes to the pathogenesis of thrombosis in patients with the lupus anticoagulant (LA), we assessed the ability of endothelium to release tissue-type plasminogen activator (t-PA) in response to standardized venous occlusion (VO) of the arm, and the extent of inhibition of t-PA, in 11 subjects with LA and a history of thrombosis and in 36 healthy normal subjects. The mean rise in plasma t-PA antigen after VO, the mean plasma free t-PA activity after VO, and the mean plasma t-PA inhibitor level prior to VO were not significantly different in subjects with LA and thrombosis and in normal subjects. Four subjects with LA and thrombosis (36%), and five of 36 healthy control subjects (14%) generated no detectable free t-PA activity after VO (“non-responders”); this difference was not statistically significant. All four “non-responders” with LA and thrombosis had normal t-PA antigen release after VO, indicating that the lack of detectable free t-PA activity after VO was due to increased inhibition of released t-PA. We conclude that abnormally reduced endothelial fibrinolytic activity is not present in the majority of subjects with LA and thrombosis. In the subset of subjects with LA and thrombosis who generate no detectable t-PA activity after VO, a stimulatory effect of LA on endothelial production of t-PA inhibitor cannot be excluded.

Autoimmune Myelofibrosis: Clinical Features, Course, and Outcome

BACKGROUND

Autoimmune myelofibrosis (AIMF) is an underrecognized cause of nonmalignant bone marrow fibrosis which occurs in the presence or absence of a defined systemic autoimmune disease. Patients with AIMF present with cytopenias and autoantibodies, and have a distinctive nonclonal myelofibrosis on bone marrow examination. AIMF is distinguished from primary myelofibrosis by the absence of splenomegaly, eosinophilia, or basophilia, and the absence of abnormal myeloid, erythroid, or megakaryocytic morphology.

OBJECTIVES

The objective of the study was to describe the clinical presentation and outcomes of patients with AIMF.

METHODS

We conducted a single-institution, retrospective chart review of patients diagnosed with AIMF to investigate clinical presentations, therapies, and outcomes.

RESULTS

Twelve patients with AIMF were identified with a mean follow-up of 5.8 years. All patients had detectable autoantibodies and the majority had concomitant autoimmune disorders. Four patients experienced a complete response of cytopenias and 3 patients experienced a partial response (PR) of cytopenias with immunosuppressive therapy. One patient achieved a PR following splenectomy. No patients were diagnosed with myeloproliferative neoplasms during the follow-up period.

CONCLUSIONS

AIMF contributes to cytopenias in the subset of patients with various autoimmune disorders. The majority of patients with AIMF experience an improvement in cytopenias with immunosuppressive therapy.

Disseminated intravascular coagulation in patients with solid tumors

Disseminated intravascular coagulation (DIC) is an occasional complication of solid tumors, usually identified at the time of presentation because of excessive bleeding, thromboembolic complications, or abnormal laboratory test results. The latter include an unexplained low platelet count, a low fibrinogen level, an elevated D-dimer level, and a prolonged prothrombin time. Prompt diagnosis and treatment of the underlying malignancy can result in resolution of the DIC. Further, if the tumor is responsive to chemotherapy, a reasonable median survival can also result. Excessive bleeding at presentation can be managed with platelet transfusions, cryoprecipitate, and fresh frozen plasma. Thromboembolic complications can be managed with continuous intravenous heparin and supportive platelet transfusions; cryoprecipitate can be used whenever necessary to support platelet and fibrinogen levels. On occasion, when excessive bleeding and venous thromboembolism occur together, placement of a vena cava filter is required, along with the administration of platelets and cryoprecipitate.

Disseminated intravascular coagulation secondary to advanced pancreatic cancer treated successfully with combination chemotherapy

Both solid and hematologic malignancies may be complicated by coagulopathies. Disseminated intravascular coagulation (DIC) in the presence of pancreatic cancer is generally unrecognized and may have fatal consequences. The diagnosis of DIC in a patient with advanced cancer is a poor prognostic indicator. Presented here is a case study consisting of two patients presenting with a new diagnosis of pancreatic cancer complicated by DIC. Aggressive supportive treatment in addition to systemic chemotherapy consisting of gemcitabine and nab-paclitaxel was initiated and DIC was controlled. An early diagnosis of DIC and the administration of systemic chemotherapy with a high response rate and an ability to reduce tumor bulk rapidly may offer some patients the probability of recovery.

Approach to the treatment, characterization and diagnosis of an acquired auto-antibody directed against factors prothrombin, factor X and factor IX: a case report and review of the literature

Bleeding disorders secondary to acquired non-inhibitory antibodies directed against vitamin K-dependent coagulation proteins are rare. In this report, the authors describe a patient with a low grade lymphoma who presented with a fatal acquired bleeding manifestation and abnormal hemostatic studies resulting from deficiencies in both prothrombin and factor X. Patient plasma samples were collected and studied for the presence of an acquired inhibitor. Levels of plasma coagulation proteins were measured using immunoassay. Patient anti-prothrombin immunoglobulin G was isolated and binding to prothrombin, prothrombin F1.2, factors IX and X was evaluated using immunoblots and competition immunoassay. Prolongation in the prothrombin time and activated partial thromboplastin time suggested a factor deficiency in the common pathway of coagulation. Functional and antigenic levels of both prothrombin and factor X were decreased. An IgG subtype-4 antibody was isolated from patient plasma using affinity chromatography on prothrombin-sepharose. This antibody was found to bind to a common metal-ion-dependent conformational epitope found on the γ-carboxyglutamic acid (Gla) domain of prothrombin, factor X and factor IX. This report represents the first description of an acquired bleeding disorder resulting from a unique cross-reactive auto-antibody against a common metal-ion-dependent antigenic structure on the Gla-domain of the vitamin K-dependent proteins.

Thrombosis in patients with paroxysmal noctural hemoglobinuria is associated with markedly elevated plasma levels of leukocyte-derived tissue factor

Thromboembolism is a frequent complication of paroxysmal nocturnal hemoglobinuria (PNH) and contributes significantly to patient morbidity and mortality. A number of mechanisms have been proposed to explain the increased incidence of this complication of PNH. Increased platelet activation with platelet microparticle formation and depression of cell surface-mediated fibrinolysis has been demonstrated in patients with PNH. We have studied two patients with hemolytic PNH who had recurrent and refractory venous thromboembolic events despite therapeutic anticoagulation. Plasma samples from both patients demonstrated marked hemostatic activation as determined by elevated plasma thrombin-antithrombin complexes (TAT) and D-dimers. Plasma samples from both patients were also shown to contain markedly elevated levels of circulating tissue factor (TF), which was shown to be predominantly derived from monocytes and macrophages. In one patient, a successful allogeneic bone marrow transplant resulted in a reduction in hemostatic activation associated with a marked decrease in circulating tissue factor to near normal levels. We propose that thrombosis in PNH results from increased tissue factor expression by complement injured CD55- and CD59-deficient monocytes and macrophages.

Primary autoimmune myelofibrosis: definition of a distinct clinicopathologic syndrome

Myelofibrosis is characterized by reticulin fibrosis of the bone marrow with resulting features of myelophthisis. Besides hematopoietic malignancies and other neoplasms involving the bone marrow, myelofibrosis has been described in association with autoimmune disorders, especially systemic lupus erythematosus. We describe the clinicopathologic features of a primary form of autoimmune myelofibrosis (AIMF) in patients who do not have systemic lupus erythematosus or another well-defined autoimmune syndrome. Absence of marked splenomegaly, peripheral blood cytopenias with mild teardrop poikilocytosis and leukoerythroblastosis, bone marrow lymphoid aggregates, and presence of autoantibodies are some of the salient features of primary AIMF. AIMF should especially be differentiated from chronic idiopathic myelofibrosis, a neoplastic myeloproliferative disease. Primary AIMF appears to have an excellent prognosis, with all patients reported in this series responding to a short course of corticosteroid therapy.

Pathology of autoimmune myelofibrosis. A report of three cases and a review of the literature

We identified 3 patients with autoimmune myelofibrosis (AM) lacking American Rheumatism Association criteria for systemic lupus erythematosus (SLE). They had 1 or 2 cytopenias and lacked serologic evidence for SLE. Autoimmune features included psoriatic arthritis and positive direct Coombs test (DCT) result, DCT-positive autoimmune hemolytic anemia, and synovitis with polyclonal hypergammaglobulinemia. Bone marrow biopsy specimens from each patient were evaluated by routine morphologic and immunohistochemical examination. They demonstrated marked hypercellularity (2 cases) or hypocellularity (1 case), moderate erythroid hyperplasia (all cases) with left-shifted maturation (2 cases), intrasinusoidal hematopoiesis (all cases), slightly to moderately increased megakaryocytes (2 cases), and grade 3 to 4 reticulin fibrosis (all cases). All lacked basophilia, eosinophilia, bizarre megakaryocytes, clusters of megakaryocytes, and osteosclerosis. Mild to moderate bone marrow lymphocytosis was noted in all cases. In 2 cases, increased small T cells and B cells formed nonparatrabecular, loose aggregates. AM is a clinicopathologic entity that may lack features of SLE. Loose aggregates of bone marrow T and B lymphocytes and the absence of morphologic and clinical features of myeloproliferative disease or low-grade lymphoproliferative disease are clues that distinguish AM from better known causes of bone marrow fibrosis.

ERGIC-53 gene structure and mutation analysis in 19 combined factors V and VIII deficiency families

Combined factors V and VIII deficiency is an autosomal recessive bleeding disorder associated with plasma levels of coagulation factors V and VIII approximately 5% to 30% of normal. The disease gene was recently identified as the endoplasmic reticulum-Golgi intermediate compartment protein ERGIC-53 by positional cloning, with the detection of two founder mutations in 10 Jewish families. To identify mutations in additional families, the structure of the ERGIC-53 gene was determined by genomic polymerase chain reaction (PCR) and sequence analysis of bacterial artificial chromosome clones containing the ERGIC-53 gene. Nineteen additional families were analyzed by direct sequence analysis of the entire coding region and the intron/exon junctions. Seven novel mutations were identified in 10 families, with one additional family found to harbor one of the two previously described mutations. All of the identified mutations would be predicted to result in complete absence of functional ERGIC-53 protein. In 8 of 19 families, no mutation was identified. Genotyping data indicate that at least two of these families are not linked to the ERGIC-53 locus. Taken together, these results suggest that a significant subset of combined factors V and VIII deficiency is due to mutation in one or more additional genes.

Treatment of a unique anemia in patients with IDDM with epoetin alfa

OBJECTIVE

To identify and treat a unique form of anemia in patients with long-term IDDM.

RESEARCH DESIGN AND METHODS

Patients with IDDM, unexplained symptomatic anemia, and serum creatinine levels of < 177 mumol/l (2.0 mg/dl) were treated with epoetin alfa (Procrit, Ortho Biotech, Raritan, NJ), 50 U/kg three times weekly, subcutaneously, to reach a target hematocrit of 38-40%. Baseline serum erythropoietin titers were measured before drug therapy.

RESULTS

Six patients were treated with epoetin alfa. Median age of the group was 74 years, with IDDM being diagnosed for a median of > 20 years. All patients had symptoms of anemia with a median hematocrit of 28.9% (range 27-31). Compared with iron deficiency control patients, the group had a limited erythropoietin (EPO) response to the degree of anemia. All patients showed increases in hematocrit, median peak of 40.9%, with median time-to-peak response of 12 weeks. Baseline symptoms of anemia resolved in all patients. No adverse effects were noted during the treatment period.

CONCLUSIONS

There is a unique form of anemia in patients with long-term IDDM and clinically normal renal function who respond to low-dose epoetin alfa therapy. The rapid response to therapy and depressed baseline erythropoietin titers suggest the anemia is due to a lack of endogenous EPO release.

Treatment of disseminated intravascular coagulation

The treatment of DIC is extremely complex, stemming from the fact that it complicates many different disorders and may have a variety of clinical manifestations. In addition, there continues to be a lack of well-controlled studies regarding various methods of management in relatively homogeneous groups of patients. Therefore treatment continues to be controversial and probably will remain so in the near future. However, it is clear that any careful clinical and laboratory observations in groups of patients with the same underlying disorder are extremely helpful in elucidating the natural history of the process, in determining its effect on the patient, and clarifying whether certain therapeutic interventions may be helpful. Therefore the continued accumulation of careful clinical studies will help in determining the proper management of DIC in patients with the same underlying disorder and in given individual situations.

Endothelial-dependent fibrinolysis in subjects with the lupus anticoagulant and thrombosis

To investigate the hypothesis that diminished endothelial fibrinolytic activity contributes to the pathogenesis of thrombosis in patients with the lupus anticoagulant (LA), we assessed the ability of endothelium to release tissue-type plasminogen activator (t-PA) in response to standardized venous occlusion (VO) of the arm, and the extent of inhibition of t-PA, in 11 subjects with LA and a history of thrombosis and in 36 healthy normal subjects. The mean rise in plasma t-PA antigen after VO, the mean plasma free t-PA activity after VO, and the mean plasma t-PA inhibitor level prior to VO were not significantly different in subjects with LA and thrombosis and in normal subjects. Four subjects with LA and thrombosis (36%), and five of 36 healthy control subjects (14%) generated no detectable free t-PA activity after VO ("non-responders"); this difference was not statistically significant. All four "non-responders" with LA and thrombosis had normal t-PA antigen release after VO, indicating that the lack of detectable free t-PA activity after VO was due to increased inhibition of released t-PA. We conclude that abnormally reduced endothelial fibrinolytic activity is not present in the majority of subjects with LA and thrombosis. In the subset of subjects with LA and thrombosis who generate no detectable t-PA activity after VO, a stimulatory effect of LA on endothelial production of t-PA inhibitor cannot be excluded.

Impaired fibrinolysis in coronary artery disease

We assessed endogenous endothelial-dependent fibrinolysis in 99 subjects with coronary artery disease (CAD) documented by angiography and in 28 control subjects with normal coronary arteries on angiography. We used specific, sensitive assays for plasma tissue-type plasminogen activator (t-PA) antigen, t-PA activity, plasminogen activator inhibitor (PAI) activity, plasminogen, and alpha-2 plasmin inhibitor (alpha-2 PI). Mean PAI activity was significantly higher, and mean t-PA activity after venous occlusion of the upper arm (a standard test of the capacity of vascular endothelium to release t-PA) was significantly lower in subjects with CAD than in subjects with normal coronary arteries. The mean increment in t-PA antigen after venous occlusion was significantly lower than normal in subjects with CAD with onset of symptoms before age 45 years. Subjects with CAD had a significantly increased mean plasma fibrinogen level compared with control subjects, and a significant positive correlation was observed between PAI activity and plasma fibrinogen in subjects with CAD. No significant abnormalities of plasminogen or alpha-2 PI were observed in any subset of subjects with CAD. These data support an association between impaired fibrinolysis and CAD, with contributions from both increased PAI activity and in younger subjects from reduced endothelial t-PA release.

Small noncleaved follicular center cell lymphoma: Burkitt's and non-Burkitt's variants in the US. II. Pathologic and immunologic features

The morphologic criteria for the two variants of small noncleaved follicular center cell (SNC FCC) lymphoma in the Lukes-Collins classification, Burkitt's (BL) and non-Burkitt's variants (NBL), were evaluated and related to the results of multiparameter laboratory and clinical studies. Forty-two patients were studied: 25 cases were classified as BL according to World Health Organization (WHO) criteria. Seventeen cases were classified as NBL on the basis of greater variability in nuclear size and shape, more prominent nucleoli, and greater variation in the amount of cytoplasm. Neoplastic follicles were present in three cases of BL and two of NBL, indicating an FCC origin for this lymphoma. Electron microscopic examination confirmed the light microscopic features. Immunoglobulin (Ig) monoclonality, as demonstrated by immunofluorescence (surface Ig) and/or immunoperoxidase staining for cytoplasmic immunoglobulin (CIg), was demonstrated in 21 of 24 (87.5%) of BL and 13 of 16 (71%) of NBL. Clinically, BL presented more frequently in extranodal sites and with gastrointestinal involvement than NBL. Bone marrow involvement was more common in NBL patients. Both groups had advanced stage disease at diagnosis. The median survival was 10.5 months in BL and 7.7 months in NBL. The results of this study indicate that BL and NBL are biologically related variants of SNC FCC lymphoma but have different presentations, which may be clinically significant.

Allogeneic bone marrow transplantation as primary therapy for chronic myelomonocytic leukemia

This is the first report of a successful bone marrow transplantation for chronic myelomonocytic leukemia. A 41-year-old woman with chronic myelomonocytic leukemia received, as primary treatment, a novel preparatory regimen consisting of high dose fractionated total body irradiation and high dose VP-16 chemotherapy followed by allogeneic marrow transplantation from her histocompatible brother. The patient is now more than two years after marrow transplantation with normal blood counts and a normal bone marrow which is of donor type. For younger patients with this disease who have a histocompatible sibling donor, bone marrow transplantation may represent a valid therapeutic option with curative potential.

The effect of isotretinoin in six patients with cutaneous T-cell lymphoma

Oral retinoids are effective in the treatment of patients with a variety of malignant and nonmalignant skin disorders, including mycosis fungoides. We treated six patients with cutaneous T-cell lymphomas with isotretinoin 1 to 2 mg/kg/d. All patients experienced symptomatic relief (fading of skin lesions and disappearance of pruritus) within two to eight weeks of starting the drug therapy; pretreatment and posttreatment biopsy specimens were unchanged. Adverse effects were minor and primarily consisted of drying of the mucous membranes. We conclude that isotretinoin is a well-tolerated, easily administered drug that provides good palliation of symptoms and signs associated with cutaneous T-cell lymphoma in patients who are unable or unwilling to comply with standard therapy.

Heterogeneity of response and survival in diffuse histiocytic lymphoma after BACOP therapy (bleomycin, doxorubicin, cyclophosphamide, vincristine, prednisone)

Diffuse 'histiocytic' lymphoma (DHL) is heterogeneous pathologically, consisting of four subtypes within Lukes-Collins; large-cleaved (LC), large non-cleaved (LNC), immunoblastic sarcoma of B cells (B-IBS), and immunoblastic sarcoma of T-cells (T-IBS). This heterogeneity is also recognized in the Cooperative Working Formulation on non-Hodgkin's lymphoma. Prior studies have suggested clinical heterogeneity of DHL as well, although conclusions were hampered by small numbers, and lack of therapeutic uniformity. We treated 57 patients with advanced DHL, using BACOP: 22 LNC, 16 T-IBS, 13 B-IBS, six LC. Complete remission rate for LNC was 64 per cent (14/22); B-IBS was 54 per cent (7/13); LC was 33 per cent (2/6); T-IBS was 25 per cent (4/16). (p = 0.10). Median survival for LNC was 27.8 months, B-IBS was 25.9, LC was 14, T-IBS was 12.0. The survival was significantly shorter for T-IBS patients when compared to the others (p = 0.01). By multi-variate analysis, histologic subtype (p = 0.02), age (p = 0.03), and stage (p = 0.06) were significant and independent prognostic variables in predicting survival. We conclude that LNC may respond the most favourably to BACOP, whereas alternative regimens appear necessary for patients with T-IBS.

Reduced alpha-2-antiplasmin levels in the nephrotic syndrome

Venous and arterial thromboembolism frequently complicate the nephrotic syndrome. Increased platelet aggregation, high levels of fibrinogen and other procoagulants, and depressed levels of antithrombin III and plasminogen are commonly cited as reasons. Less attention has been paid to changes in the hemostatic system which might protect against thrombosis. We found a high frequency of reduced alpha 2-antiplasmin levels in 40 patients with nephrotic syndrome, correlating with serum albumin and with antithrombin III levels. Since alpha 2-antiplasmin is a major determinant of the sensitivity of fibrin thrombi to lysis, and since reduced levels would be expected to promote fibrinolysis, we conclude that in many patients with nephrotic syndrome depressed antiplasmin levels may help reduce the risk of thrombosis posed by diminished antithrombin III levels.

Clinical significance of accelerated fibrinolysis in liver disease

We compared site and severity of bleeding in 46 patients with cirrhosis of the liver and accelerated fibrinolysis (defined as a dilute whole-blood clot lysis time less than 2 h) to 44 patients with cirrhosis of the liver and normal fibrinolysis (dilute whole-blood clot lysis time greater than 4 h). Patients with accelerated fibrinolysis had a significantly higher incidence of severe soft-tissue bleeding after trauma and a trend toward increased intracranial bleeding. Mucosal, postoperative, and gastrointestinal bleeding were equally frequent in the two groups. The median partial thromboplastin time was significantly longer, and the median bilirubin and fibrin/fibrinogen degradation product levels were significantly higher in the group with accelerated fibrinolysis, but median prothrombin time, platelet count, and levels of fibrinogen and serum albumin were comparable. The fibrinolytic inhibitor epsilon-aminocaproic acid successfully controlled bleeding in 4 of 6 cases used. Accelerated fibrinolysis may predispose patients with cirrhosis to soft-tissue and intracranial bleeding.

Use of noninvasive laboratory testing in the prediction of thrombosis in the nephrotic syndrome

A noninvasive method for diagnosing thrombosis in the nephrotic syndrome could be useful clinically. We measured hematocrit, fibrinogen, creatinine, antithrombin III, plasminogen, and alpha-2-plasmin inhibitor levels in 20 patients with nephrotic syndrome objectively studied for the presence of thrombosis, and found that by using combinations of three or more of these variables good discrimination could be obtained between those patients with and without thrombosis. We conclude that it is possible to predict risk of thrombosis in nephrotic syndrome using relatively simple noninvasive laboratory tests.

Small noncleaved follicular center cell (FCC) lymphoma: Burkitt and non-Burkitt variants in the United States. I. Clinical features

With the understanding that Burkitt's lymphoma was of follicular center cell (FCC) derivation, Lukes and Collins classified the tumor, descriptively, as small noncleaved FCC lymphoma. Two subtypes were described: Burkitt and non-Burkitt. Attempting to define the clinicopathologic features of the subtypes, we studied 42 patients: 25 Burkitt and 17 non-Burkitt. Histologically, the Burkitt tumor demonstrated remarkable uniformity of nuclear size and contour, whereas the non-Burkitt variant had greater variability. Immunoglobulin monoclonality was demonstrated in 83% of Burkitt and 81% of non-Burkitt cases. Burkitt patients tended to be younger. Gastrointestinal disease was seen in 15 Burkitt and only four non-Burkitt patients (P less than 0.05). Disseminated disease was found in the majority of both variants. Marrow involvement was demonstrated in 4.5% of Burkitt and 37.5% of non-Burkitt patients (P less than 0.05). Median survival of Burkitt patients was 10.5 months versus 7.7 months in the non-Burkitt group. The authors believe that significant biologic differences between the variants have been demonstrated, which may be of potential value to the clinician.

'Unlearning' has a stabilizing effect in collective memories

Crick and Mitchison have presented a hypothesis for the functional role of dream sleep involving an 'unlearning' process. We have independently carried out mathematical and computer modelling of learning and 'unlearning' in a collective neural network of 30-1,000 neurones. The model network has a content-addressable memory or 'associative memory' which allows it to learn and store many memories. A particular memory can be evoked in its entirety when the network is stimulated by any adequate-sized subpart of the information of that memory. But different memories of the same size are not equally easy to recall. Also, when memories are learned, spurious memories are also created and can also be evoked. Applying an 'unlearning' process, similar to the learning processes but with a reversed sign and starting from a noise input, enhances the performance of the network in accessing real memories and in minimizing spurious ones. Although our model was not motivated by higher nervous function, our system displays behaviours which are strikingly parallel to those needed for the hypothesized role of 'unlearning' in rapid eye movement (REM) sleep.

Severe depression of antithrombin III associated with disseminated intravascular coagulation in women with fatty liver of pregnancy

Serial coagulation studies were done in four women with acute fatty liver of pregnancy. All had coagulopathy, laboratory evidence of diffuse intravascular coagulation, and marked depletion of plasma antithrombin III. Two of these women had persistent intravascular coagulation for 4 days after delivery. The others had prompt control of intravascular coagulation coincident with elevation of the antithrombin III concentration by plasma transfusion. Severe antithrombin III depression may be a major cause of the persistent intravascular clotting and can be corrected by plasma transfusion.

Antithrombin III and anti-activated factor X activity in patients with acute promyelocytic leukemia and disseminated intravascular coagulation treated with heparin

Two patients diagnosed as having acute promyelocytic leukemia (APL) and disseminated intravascular coagulation (DIC) were closely followed from the day of admission until completion of the first course of chemotherapy with serial coagulation studies including plasma levels of functional antithrombin III activity (AT III) by fluorometric analysis and anti-activated Factor X activity (anti-Xa) by coagulation assay. Both patients were treated with intravenous heparin and the presence of heparin in plasma was followed by the thrombin time. Consistently normal levels of AT III (greater than 80%) were found despite evidence of intravascular coagulation. However, plasma levels of anti-Xa were often low (less than 70%) and increased only in the presence of heparin. The significance of these results in relationship to heparin therapy for disseminated intravascular coagulation of APL is discussed.

Successful therapy of convoluted T-lymphoblastic lymphoma in the adult

Fifteen adult patients with biopsy-proven convoluted T-lymphoblastic lymphoma were treated with an aggressive regimen, modified from the LSA2-L2 protocol used for childhood lymphoma. The treatment schema consisted of induction phase, including cyclophosphamide, vincristine, prednisone, adriamycin, and 2000 rads to mediastinum, as well as intrathecal methotrexate. Consolidation phase included cytosine arabinoside, 6-thioguanine, L-asparaginase, and CCNU, along with cranial irradiation and further intrathecal methotrexate. Maintenance consisted of cyclical chemotherapy and intrathecal methotrexate, continuing for a total of 3 yr. Median age in the group was 25 yr (range 16-73). There were 8 males and 7 females. At diagnosis, 9 patients had mediastinal involvement, and 9 had bone marrow involvement. Five of these demonstrated malignant cells in the peripheral blood. Complete clinical response was attained in 11 patients. Three patients achieved partial response. Four complete responders have relapsed, 1 in the central nervous system at 6 mo. and 1 in nodal sites at 3 mo, 1 in multiple sites at 24 mo. and 1 in bone marrow at 42 mo while off all chemotherapy for 6 mos. At this time, median survival of all patients is 28.3 mo. and median relapse-free survival is 21 mo. The median survival for complete responders in excess of 71 mo. while the median relapse-free survival for this group is 41 mo.

Antithrombin III and anti-activated factor X activity in patients with acute promyelocytic leukemia and disseminated intravascular coagulation treated with heparin

Two patients diagnosed as having acute promyelocytic leukemia (APL) and disseminated intravascular coagulation (DIC) were closely followed from the day of admission until completion of the first course of chemotherapy with serial coagulation studies including plasma levels of functional antithrombin III activity (AT III) by fluorometric analysis and anti-activated Factor X activity (anti-Xa) by coagulation assay. Both patients were treated with intravenous heparin and the presence of heparin in plasma was followed by the thrombin time. Consistently normal levels of AT III (greater than 80%) were found despite evidence of intravascular coagulation. However, plasma levels of anti-Xa were often low (less than 70%) and increased only in the presence of heparin. The significance of these results in relationship to heparin therapy for disseminated intravascular coagulation of APL is discussed.

Diagnosis and management of disseminated intravascular coagulation: the role of heparin therapy

Disseminated intravascular coagulation (DIC) is caused by a variety of underlying disorders, and criteria for diagnosis are not well defined. However, the most helpful are a low platelet count, positive plasma protamine test, and fibrinogen and fibrin degradation product levels viewed in the context of the patient's underlying disease. The cornerstone of therapy is prompt treatment of the underlying disease and elimination of the trigger mechanism. Additional treatment must be individualized, and generalizations are difficult to make. However, if the patient has low hemostatic factors and is actively bleeding or requires an invasive procedure, then replacement with the appropriate hemostatic factors should be tried. Heparin is indicated in patients with purpura fulminans and venous thromboembolism, but there is little evidence that heparin reverses organ dysfunction associated with DIC. In addition, heparin is also probably indicated in patients with retained dead fetus and hypofibrinogenemia prior to induction of labor, excessive bleeding associated with a giant hemangioma, and neoplastic disease, particularly promyelocytic leukemia. Although the use of heparin in acute forms of DIC remains controversial, the majority of studies suggest that it is not helpful. The role of antithrombin III (AT-III) concentrates is unknown, but they theoretically may be helpful when DIC is associated with very low AT-III levels, as is seen in liver disease.

Syndrome of an acquired inhibitor of factor VIII responsive to cyclophosphamide and prednisone

Six patients with an acquired inhibitor of factor VIII had the following clinical characteristics: older age group; absence of definable, underlying disease; a low titer of the factor VIII inhibitor; notable residual plasma factor VIII activity despite the inhibitor; serious bleeding not controlled by infusion of factor VIII; and disappearance of the inhibitor after treatment with cyclophosphamide and prednisone. These findings delineate a syndrome characteristic of a subset of patients with an acquired factor VIII inhibitor. It is important to emphasize that such patients may bleed uncontrollably despite the misleading presence of residual plasma factor VIII activity in vitro, and that the inhibitor disappears after immunosuppressive therapy. Thus, we believe that patients with this syndrome should be treated with cyclophosphamide and prednisone as soon as the inhibitor is identified.

Immunoblastic sarcoma of T-cell versus B-cell origin: I. Clinical features

Within the Lukes-Collins classification system of malignant lymphoma, a tumor of large transformed lymphocytes, termed immunoblastic sarcoma (IBS), is described. This morphological type would have been included within the "histiocytic" category of Rappaport. Immunoblastic sarcoma may be of B-lymphocytic or T-lymphocytic origin. Since differences or similarities of these two variants have not yet been described, we reviewed the case histories of 35 such patients, all of whom had immunologic marker studies performed. Nineteen patients had T-cell IBS (T-IBS), whereas 16 had B-cell IBS (B-IBS). Median age for both groups was approximately 50 yr. A history of prior immune disorder was found in 31% of B-IBS and 16% of T-IBS cases. Prior lymphoproliferative malignancy was noted in 21% of T-IBS and 13% of B-IBS patients. All T-IBS patients first presented because of lymphadenopathy, whereas 56% of B-IBS cases initially presented because of extranodal disease. Systemic "B" symptoms were common in both. Similarly, most patients had widespread disease (stage III or IV) at diagnosis. Clinically suspected hepatic (p = 0.05) and retroperitoneal node (p = 0.01) involvement were more often found in T-IBS. Forty-one percent of T-IBS patients demonstrated polyclonal hypergammaglobulinemia, a finding seen in no B-IBS patient (p = 0.02). Although not statistically significant because of small numbers of patients, data on therapy and survival suggest that IBS of B-cell type may be successfully treated with aggressive, multiagent chemotherapy, while alternative approaches appear warranted in T-cell disease.

Distal renal tubular acidosis in multiple myeloma

A patient with early multiple myeloma was initially seen with a severe hyperchloremic metabolic acidosis with a normal anion gap and a urine pH of 6.3. The patient did not have glucosuria, aminoaciduria, of phosphaturia. A bicarbonate loading test showed that the fractional excretion of bicarbonate was less than 5% and confirmed the hypothesis that the patient had a distal renal tubular acidification defect. The pathophysiologic mechanism that caused this defect is unknown, but it is associated with the presence of a serum M component (IgG-lambda) and a urine M component (lambda light chains). Multiple myeloma should be considered in the differential diagnosis of conditions of patients who have a renal tubular acidification defect.

Clinical and immunologic spectrum of plasmacytoid lymphocytic lymphoma without serum monoclonal IgM

As first suggested by Lukes & Collins (1975), and recently confirmed in the literature, the pathological lesion associated with Waldenström's macroglobulinaemia can be found in patients with serum IgG or IgA monoclonal proteins. To expand upon the clinical and immunologic spectrum of this lesion, we reviewed the records of 12 patients with identical tumour morphology, though lacking an IgM paraprotein. The median age of the patients was 62 years. In five patients the tumour secreted monoclonal IgG, while one secreted monoclonal IgA. One patient had normal serum protein electrophoresis, although monoclonal light chains were demonstrated on urinary protein electrophoresis. The remaining patients had no detectable monoclonal protein. Marker studies demonstrated the B cell origin of tumour, these findings were consistent with the monoclonal protein secreted. Clinically, these cases varied, from peripheral blood involvement resembling chronic lymphocytic leukaemia, to typical lymphomatous processes, to presentations resembling multiple myeloma, reflecting the similarity of all of these conditions as varying expressions of neoplasia of the B cell system.

Positive Coombs test in Hodgkin's disease: significance and implications

To clarify the clinicopathologic characteristics of Coombs' positivity in Hodgkin's disease, the records of 71 cases were reviewed. The direct Coombs test was positive in seven. Mean age of the seven was 22 yr (range 11-33). All were males. All had extensive disease (pathologic stage III or IV) and six had systemic (B) symptoms. Four had mixed cellularity; three had nodular sclerosis. The positive Coombs test was detected at original diagnosis in three and at time of relapse in four. Although all were anemic, only three had evidence of overt hemolysis. The antibody responsible for Coombs positivity was characterized in three and fulfilled the criteria for IgG anti-It. The presence of a positive direct Coombs test in the patient with Hodgkin's disease suggests active and advanced disease. The presence of IgG anti-It may represent a unique antibody in the Coombs-positive hemolytic anemia associated with Hodgkin's disease.

Primary mediastinal lymphoma in adults

The incidence of primary mediastinal lymphoma in adults was investigated in 184 patients with non-Hodgkin's lymphoma. This entity was defined as disease within the mediastinum in patients who presented with symptoms due to an enlarging mediastinal mass. Of 184 patients, 17 presented with primary mediastinal lymphoma. All had a diffuse histologic pattern. The most common pathologic type was poorly differentiated lymphocytic lymphoma, diffuse (PDL-D), (11 cases). In nine of these 11 cases the patients had tumors of convoluted lymphocytes. The presentation was rapid in onset, with heart failure, pericarditis, dyspnea and superior vena caval syndrome predominating. Eleven of the 17 were clinical stage I or II, but eight of these had widespread disease on pathologic staging or rapid dissemination soon after diagnosis. In conclusion (1) primary mediastinal lymphoma is always diffuse in histology. (2) The most frequent pathologic type is PDL-D, with convoluted morphology. (3) Compression of vital intra-thoracic structures is common. (4) Although seemingly localized at presentation, this entity usually implies disseminated disease.

Use and efficacy of pneumococcal vaccine in patients with Hodgkin disease

Fulminant bacterial sepsis has been described in patients with Hodgkin disease who have undergone splenectomy for staging purposes. The organisms commonly associated with sepsis in this setting include Streptococcus pneumoniae and Haemophilus influenzae. Polyvalent pneumococcal vaccine (Merck) has recently been licensed and has been suggested for use in patients with Hodgkin disease who are at risk for postsplenectomy sepsis. We administered 14-valent pneumococcal vaccine to 24 patients with Hodgkin disease and 24 normal controls, and measured antibody response to 13 antigens at time of immunization and at 3 wk and 3 mo following immunization. Our results indicate that patients who have been previously treated for Hodgkin disease, with chemotherapy, radiotherapy, or both, have severe impairment of antibody response. Untreated patients, however, respond in a manner similar to normal controls.

Quantitative anisocytosis as a discriminant between iron deficiency and thalassemia minor

The coefficient of variation (CV) of red cell size, as measured by electronic red cell sizing (erythrography), was less than 14.0% in 20 normal subjects. In 22 of 25 patients with beta-thalassemia minor and microcytosis (mean corpuscular volume [MCV] less than 70 fl), CV was less than 14.0%; in the other 3, CV was 14.0%--14.9%. In 53 patients with iron deficiency anemia and MCV less than 70 fl, CV always was greater than 14.0%. In 7 patients with alpha-thalassemia minor and MCV less than 70 fl, CV was less than 14.0% in all 7. Among patients with microcytosis, erythrography appears to be an excellent technique for rapidly distinguishing between iron deficiency and alpha or beta thalassemia minor.

Immunoblastic sarcoma: a clinical description

We reviewed the clinical records of 33 patients with Immunoblastic Sarcoma in order to further describe this disease clinically. Several common features were found. Thirty percent of the patients had a history of a prior immune disease or lymphoproliferative malignancy. Forty-four percent of the patients tested had a diffuse hypergammaglobulinemia. Lymphopenia (less than 1,000/mm3) was found in 45%, and anemia occurred in 73%. At initial presentation, 30% of the cases were clinically staged as either stage I or II, whereas 70% were found to be stage III or IV. Forty-nine percent of the patients had systemic symptoms at presentation. The median survival was 14 months. Advanced stage of disease, lymphopenia, and presence of systemic symptomatology were associated with significantly decreased survival times (p less than .05). We conclude that IBS is a clinical entity often associated with prior immune disease and/or diffuse hypergammaglobulinemia.

Convoluted lymphocytic lymphoma in adults: a clinicopathologic entity

Twelve adults had a distinct clinicopathologic type of malignant lymphoma that closely resembles the mediastinal lymphomas of childhood. Nine patients presented with mediastinal masses, and seven had symptoms related to intrathoracic compression. Seven patients presented with or developed leukemia, and in four of these patients the central nervous system (CNS) became involved. Structurally, the tumor cells had a distinctive stippled chromatin pattern, in addition to the characteristic nuclear convolutions. Tumor cells from five patients were studied immunologically, and, in each case, the tumor cells formed rosettes with sheep erythrocytes. The response to combination chemotherapy was rapid and dramatic, but usually transient, with relapse in the CNS or previously involved sites. The above data strongly suggest that these cases represent a distinct clinicopathologic entity that should be treated similarly to childhood leukemia and lymphoma, with intensive multiple agent induction, CNS prophylaxis, possibly radiation therapy to initially involved sites, and prolonged maintenance.

Acquired inhibitors of factor V

The clinical and laboratory data on the 12 patients with an acquired inhibitor to factor V have been reviewed. The degree of clinical bleeding in these patients varied from none to severe, and in most patients the inhibitor was transient. The combination of a markedly prolonged partial thromboplastin time and Quick prothrombin time and failure of normal plasma to correct these tests, in the presence of a normal thrombin and prothrombin and proconvertin time, seems to be pathognomonic for a factor V inhibitor. The inhibitors have physicochemical properties of immunoglobulins and a few have been characterized as polyclonal IgG antibodies or a mixture of IgM and IgG antibodies. The etiology and pathophysiologic mechanism of their development is unknown, but there seems to be a close relationship to major surgery. When tested with inhibitor plasma, the plasmas from 9 patients with hereditary factor V deficiency from 7 unrelated families did not contain factor V antibody-neutralizing material.

Staging laparotomy and splenectomy for Hodgkin's disease

The major objective of diagnostic laparotomy in Hodgkin's disease is to define the extent of involvement not detectable by nonoperative means. Fifty patients in this institution had operative staging procedures; six for recurrent disease three to 11 years after initial therapy. Twenty-four patients had nodular sclerosis, 23 mixed cellularity, and three had other types. The clinical stages were advanced in 13 patients and decreased in seven patients. Two patients (both had mixed cellularity and systemic symptoms) had positive wedge biopsy of the liver, whereas direct needle biopsy was negative. Nineteen spleens contained Hodgkin's disease but only three could be palpated on physical examination. About half the patients with abnormal lymphangiograms had positive periaortic nodes; lymphangiogram had a false negative rate of 12%. Additional procedures performed included appendectomy, oophoropexy, and resection of Meckel's diverticulum. There was no mortality and only one case had severe postoperative Salmonella septicemia. Our findings are comparable with those reported in the literature.

Prothrombin complex concentrate

A hemophilliac with a factor VIII inhibitor was bleeding massively from an extensive surgical wound. After ten days of unsuccessful management by conservative measures, he was given a single infusion of prothrombin complex concentrate (Konyne). Bleeding stopped immediately and the wound healed without further recurrence of bleeding. Although the activated partial thromboplastin time shortened following the infusion, the exact physiologic mechanism whereby these concentrates bypass the need for factor VIII clotting activity is unknown.

Relationship of contact activation cofactor (CAC) procoagulant activity to kininogen

Contact activation cofactor (CAC) facilitates the interaction of factors XI and XII. Patients lacking CAC have a coagulation defect and are deficient in high molecular weight kininogen. The coincidence of these two defects suggests that a single protein may be responsible for both physiologic functions. Immunologic and activity studies have been made on isolated CAC to clarify the relationship between CAC and kininogen. CAC forms a single precipitin line with anti-human kininogen, and antikininogen neutralizes CAC activity. CAC and high molecular weight kininogen show a reaction of identity on immunodiffusion against rabbit anti-CAC. Anti-CAC forms two precipitin lines with normal plasma which can be identified as high and low molecular weight kininogen. Monospecific immunoabsorbed anti-CAC forms a single precipitin line with plasma high molecular weight kininogen and neutralizes CAC activity. Cleavage of kinin fragment from CAC by insoluble trypsin or kalikrein does not proportionally reduce procoagulant activity. CAC neutralized by anti-CAC can release kinins on exposure to trypsin or kallikrein. The results support the conclusions that CAC procoagulant activity is a function of high molecular weight kininogen, that antigenic determinants unique to high molecular weight kininogen are shared by the CAC portion of the molecule, and that the clotting reactions may occur at a site removed from the kinin peptide.