Acute myelofibrosis--a leukemia of pluripotent stem cell. A report of three cases and review of the literature

The histogenesis of blasts in acute myelofibrosis is generally regarded to be of megakaryocytic origin. Three case reports are presented and 19 other reported cases were reviewed from the literature where the cells of origin appear to be myeloblasts, myelomonoblasts, lymphoblasts, or undifferentiated blasts. It is therefore postulated that acute myelofibrosis is a hemopoietic stem cell disorder, and acute megakaryocytic leukemia (FAB-M7) represents one subset of the disorder.

Anemia of chronic disease: a review of pathogenesis

Although anemia of chronic disease is a common hematologic disorder, the pathogenesis of the disease is still not well understood. Various workers have demonstrated decreased red cell life span, decreased erythropoietin levels, and inappropriate response of the bone marrow to the degree of anemia. The iron metabolism in the anemia of chronic disease is abnormal in that the macrophages in the bone marrow hold onto iron and do not release it for reutilization by the erythroid precursors. More recent studies have focused attention on cytokines produced by macrophages. These are interleukin-1 and tumor necrosis factor. These cytokines appear to be involved in both red cell production and ferrokinetics. Greater understanding of the biology of the cytokines may be the key to understanding the pathogenesis of anemia of chronic disease.

Immunosuppressive mechanisms in pure red cell aplasia--a review

Pure red cell aplasia (PRCA) has been associated with a variety of clinical disorders, and various autoimmune mechanisms have been described to account for the red cell suppression. Primary PRCA occurs via both humoral and cell mediated mechanisms. Recent evidence using gene rearrangement studies indicates PRCA with T-lymphocytosis is a clonal chronic T cell lymphoproliferative disorder in which the T cells suppress erythropoiesis. Called T cell lymphocytosis and cytopenia (TCLC), this disorder has unique features, such as frequent rheumatoid arthritis (RA) and neutropenia. A subset of this disorder with natural killer (NK) like cells also exists, though direct NK cell suppression has not been proven. In secondary PRCA, both humoral and cellular suppression of erythropoiesis have also been described, except in chronic lymphocytic leukemia (CLL) where T cell suppression primarily accounts for the red cell aplasia. A role for the cell-adherent layer of the bone marrow, including macrophages, has also been demonstrated.

Thrombotic thrombocytopenic purpura: a brief review of recent literature

Thrombotic thrombocytopenic purpura is a disease characterized by hemolytic anemia, thrombocytopenia, and neurological symptoms. Platelet thrombi in small vessels are formed as a result of endothelial injury or primary platelet aggregation or both. Etiology and pathogenesis, however, are not completely understood. Therapy, at one time nonexistent, has progressed to include plasma exchange, steroids, antiplatelet drugs, splenectomy, vincristine, and gamma globulin, thus improving the prognosis significantly over that of the mid-1960s.

The congo red stain revisited

The Congo red stain has undergone several modifications since it was first used by Bennhold in 1922 in order to increase the specificity for staining amyloid. Most of the laboratories in the United States use the method of Puchtler which uses alkaline Congo red solution. Some of the variables associated with the procedure were investigated by us. Our results showed the following: (1) amyloid showed green birefringence at all levels between 4 to 12 mu thick sections with better visualization of small deposits with increased thickness. Best results were obtained with 8 mu thick sections; (2) omission of the pretreatment with alkaline alcoholic solution of sodium chloride (NaCl) did not affect the sensitivity of the method; (3) the use of polar mounting media had no effect on amyloid and collagen birefringence; (4) 50 percent saturation of the Congo red staining solution with NaCl caused strong staining of collagen, elastic fibers and eosinophilic granules. In addition, collagen showed green birefringence and dichroism and its differentiation from amyloid became difficult; and (5) using the staining solution fully saturated with NaCl, no positive staining was seen with tissues other than amyloid. Collagen and elastic fibers showed red fluorescence which was of less intensity than amyloid. It is our conclusion that the method of Puchtler for detecting amyloid gives better results if the staining solution is fully saturated with NaCl. The pretreatment step may be deleted without compromising the quality of staining. Improved staining of amyloid enhances the specificity of green birefringence, dichroism, and red fluorescence.

MR imaging of hyperacute intracranial hemorrhage in the cat

Hyperacute intracerebral hematomas were successfully created in five cats by injecting a prepared blood sample in which the oxygen (O2) saturation ranged from 0-80%. T1- and T2-weighted spin-echo sequences and T2-weighted gradient refocused scans were obtained 2.5-10 hr after injection on a 1.5-T imaging system. Detailed histology or electron microscopy was performed on each brain to confirm the presence of intact red blood cells in a retracted clot matrix. Areas of the hematoma were hypointense relative to brain in all five cats on the gradient refocused scans. The hematoma was isointense relative to brain on the T1- and T2-weighted spin-echo scans in all cats except one, which suffered a seizure/respiratory arrest and died during the scanning procedure. Portions of the hematoma in this animal had a hypointense T2-weighted signal and a hyperintense T1-weighted signal, which corresponded to the predicted MR properties of intracellular methemoglobin. We hypothesize that acute (less than 10 hr old) hematomas that contain virtually 100% intracellular deoxyhemoglobin may not appear hypointense relative to brain on T2-weighted scan sequences at 1.5 T unless surrounding tissue hypoxia and/or anoxia promote additional changes, one of which may be the formation of intracellular methemoglobin.

Effect of clot formation and retraction on spin-echo MR images of blood: an in vitro study

Phantoms were constructed that contained red blood cell (RBC)-free clots in varying stages of clot retraction. MR images of these samples were compared with those of retracted whole venous blood clots and a fresh rat brain standard. Images were obtained at 0.3 T, 0.5 T, 1.0 T, 1.5 T, and 2.4 T with T1-, spin-density- and T2-weighted spin-echo pulse sequences. The presence or absence of venous blood cells in the clot caused only minor differences in T2- and spin-density-weighted images of the clots at or below 1.5 T. On T2-weighted scans, the retraction of the RBC-free clot resulted in a progressive decrease in signal intensity at 2.4 T. Fully retracted RBC-free clots were markedly hypointense relative to serum and ranged from slightly hyperintense to isointense with brain and venous clots at 0.5-1.5 T. There were no striking concomitant signal intensity changes on the spin-density- or T1-weighted scans, which could have caused the changes seen on the T2-weighted images of the clots. Our results indicate that the physical basis of these MR effects in the RBC-free clots is the concentration of plasma protein. The combined concentration of plasma protein and the tightly packed RBC proteins in the venous clots causes the strikingly similar MR appearance of venous and RBC-free clots on clinical images. These results do not demonstrate the presence of the previously postulated selective T2 relaxation of intracellular paramagnetic deoxyhemoglobin in these in vitro venous clots.

Fat overload syndrome. An autopsy study with evaluation of the coagulopathy

Fat overload syndrome is a rare complication of intravenous fat emulsion therapy. It is characterized by sudden elevation of the serum triglyceride level, fever, hepatosplenomegaly, coagulopathy, and variable end-organ dysfunction. The illness is generally discrete, and symptoms regress as the lipemia clears. The transient nature of the syndrome has allowed only speculation as to its pathogenesis. The authors report an autopsy study of a child who died during an acute episode of fat overload and document the causative role of fat sludging in the associated end-organ failure. In addition, they offer evidence that the coagulopathy, previously an enigma, results from primary fibrinolysis, possibly caused by release of tissue plasminogen activators from the damaged endothelial cells.

T2 effect of hemoglobin concentration: assessment with in vitro MR spectroscopy

T2 values were measured at 0.23 and 4.7 T for deoxygenated blood samples (43%-73% O2 saturation) with hematocrits of 18%-100%. An increase in the hematocrit produced a marked reduction in T2 at both field strengths. Cell lysis did not abolish the T2 effect at either field strength. The authors conclude that the increase in hemoglobin concentration caused by formation of a retracted clot is a cause of the hypointense appearance of acute hemorrhage compared with brain on T2-weighted clinical magnetic resonance images. This is particularly important on low-field-strength systems, which are not sensitive to the T2 shortening effects of paramagnetic intracellular deoxyhemoglobin.

Methods for staining amyloid in tissues: a review

The traditional way of identifying amyloid in tissue sections has been staining with Congo red and demonstration of green birefringence under crossed polarizers. The original method of Congo red staining, described by Bennhold in 1922, has undergone several modifications to improve its sensitivity, specificity, and reliability. The most common modification is the alkaline Congo red method described by Puchtler and co-workers in 1962. Specificity is improved by using freshly prepared stain and a staining solution fully saturated with sodium chloride. Amyloid proteins can be further distinguished by autoclaving or by treating the tissue with potassium permanganate or alkaline guanidine. Autoclaving the tissues at 120 C for 30 min causes protein AA to lose its affinity for Congo red. Prolongation of autoclaving to 120 min abolishes the Congophilia of protein AL, but prealbumin-related amyloid shows little or no change. Treatment of the tissue with potassium permanganate causes protein AA and B2-microglobulin amyloid to lose their affinity to Congo red. Protein AA fails to stain with Congo red after treatment with alkaline guanidine for 1 min and protein AL and systemic senile amyloid protein (SSA) after 2 hr. Familial amyloid protein (FAP), prealbumin type, can stand 2 hr of alkaline guanidine treatment without losing its ability to stain with Congo red. Other methods of detection of amyloid include fluorescent stains, e.g., thioflavin T or S, and metachromatic stains such as crystal violet. Immunofluorescence and immunoperoxidase methods are used to identify and classify amyloid proteins in tissues. Antibodies against the P component, proteins AA and AL and FAP have been used with great precision. Due to cross-reactivity, these methods do not differentiate between some types of familial and senile systemic amyloidosis.

Suppression of hemoglobin H in disorders of iron metabolism

Disorders of iron metabolism affect the expression of hemoglobin H in hemoglobin H disease. Two cases of iron deficiency with reduced synthesis of hemoglobin H are described in the literature. We report two more cases, one with anemia of chronic disease and another with alcoholic sideroblastic anemia where the hemoglobin H was not detected at presentation and appeared after treatment of the underlying disorder. The pathogenesis of suppression of hemoglobin H is discussed.

Effect of profound hypothermia on leukocytes and platelets

Seventeen patients who underwent aortic arch replacement were subjected to profound hypothermia and circulatory arrest. At maximum cooling, platelet count dropped from 184 +/- 122 to 37 +/- 30 thousand per microliter, and the total leukocytic count fell from 6.27 +/- 4.0 to 1.47 +/- 0.6 thousand per microliter. The thrombocytopenia was partially reversed with rewarming. The total white cell count consistently returned to precooling values or higher (10.5 +/- 4.0). The mechanism for this cold induced phenomenon is not well understood.

Immune thrombocytopenia following alpha-interferon therapy in patients with cancer

Immune thrombocytopenia occurred in five patients with cancer receiving alpha-interferon. The median pretreatment platelet count was 217,000/cu mm, which fell to a median of 12,000/cu mm after a median of 25 days of interferon therapy. All had normal numbers of megakaryocytes, with dysplasia noted in three; all four who were tested had platelet-associated immunoglobulin. All had normalization of platelet counts with prednisone therapy. Four tolerated re-treatment with interferon, two with concurrent prednisone administration and two others following splenectomy. Immune thrombocytopenia should be considered in patients who become thrombocytopenic during interferon therapy.

Prekallikrein (Fletcher factor) deficiency

One new case and 29 reported cases of hereditary prekallikrein (Fletcher factor) deficiency are reviewed. Abnormalities in the coagulation, fibrinolytic, complement, and kinin systems are described. These cases are discovered incidentally by prolonged partial thromboplastin times (PTTs) which correct with extended incubation in the presence of a contact activator. Prekallikrein levels are less than two percent of normal levels. In general, the remainder of the coagulation profile is normal, and no bleeding diathesis is present. Most patients are black and the incidence of consanguinity is increased. The disease is transmitted in an autosomal recessive manner. Acquired Fletcher factor disease is a moderate prekallikrein deficiency present in many common disease states. Its clinical significance is largely unknown. Both acquired and hereditary forms may rarely predispose to thrombotic phenomena.

Heparin monitoring during cardiopulmonary bypass

Three procedures have been compared for monitoring heparin in patients undergoing cardiopulmonary bypass: (1) activated clotting time (ACT) (2) protamine titration, and (3) fluorometric substrate assay. The ACT monitors the degree of anticoagulation. It is easy to perform and is relatively inexpensive, however, it does not correlate well with heparin levels and may not accurately predict the protamine dose for neutralization of heparin at the completion of bypass. A protamine titration assay or an assay using a thrombin-sensitive fluorometric substrate measures the heparin level and calculates the protamine requirement at the completion of surgery; however, these assays do not indicate the degree of anticoagulation. The fluorometric assay is the less expensive of the two assay measuring heparin, but it requires an experienced technologist to perform the test.

Acute myelofibrosis. A report of four cases and review of the literature

Four new cases of acute myelofibrosis are reported, and 63 cases reported in the literature are reviewed. The typical features of this disease include a rapidly progressive clinical course; nonspecific symptoms such as weight loss, anorexia, fatigue and weakness; the absence of organomegaly; pancytopenia; circulating blast cells; and mild abnormalities in the red blood cell morphology. The bone marrow aspirates are usually "dry." The bone marrow biopsies are essential for the diagnosis and show four consistent features: hypercellularity, reticulin fibrosis, proliferation of blast cells and bizarre, atypical megakaryocytes. In 16 cases, the blast cells in peripheral blood and bone marrow, which are unclassifiable by conventional morphology, could be identified as megakaryoblasts by ultrastructural and immunocytochemical techniques. It is concluded that acute myelofibrosis is a definite clinicopathologic entity, which may be related to acute megakaryoblastic leukemia.

Idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura occurs at all ages, in acute and chronic forms. Children mainly have the acute form, which usually follows a recent viral illness, occurs equally in both sexes, and generally resolves within six months. Chronic idiopathic thrombocytopenic purpura occurs more often in adults, often has an insidious onset, and shows a three:one female preponderance. Both forms are now thought to be due to an antiplatelet antibody, usually of the IgG class (platelet-associated IgG), which coats autologous platelets and leads to their phagocytosis and destruction by the reticuloendothelial system. In most patients, the spleen is the major site of the production of this platelet antibody and the destruction of the platelets. Many methods have been developed to detect this antiplatelet factor in the serum and on the platelets of patients with idiopathic thrombocytopenic purpura. Recent methods are becoming highly sensitive and may soon be simple and fast enough for routine clinical use and should significantly aid the diagnosis and management of these patients. Platelet-associated IgG levels appear significantly higher in patients with idiopathic thrombocytopenic purpura than in normal subjects, and in patients with nonimmune thrombocytopenia. Higher levels are also seen in children than in adults, and in acute cases than in chronic ones. Platelet-associated IgG levels also vary inversely with platelet count and platelet life span, can predict the disease course and response to therapy, and may predict neonatal consequences of maternal idiopathic thrombocytopenic purpura. Evidence of other alterations in immune status, as well as alterations in platelet function and HLA associations, remains controversial. Classic treatment with corticosteroids and splenectomy remains highly successful in most cases. More recent therapies include the use of immunosuppressants and alkaloid-coated platelets, plasma-exchange transfusion, and high-dose immunoglobulin. Overall, fewer than 5 percent of patients have severe hemorrhage or refractory or fatal disease.

Viscoelastic measurement of clot formation: a new test of platelet function

Assessment of platelet function presents a challenge to the investigators in the clinical field. An instrument, Sonoclot, is described which measures changes in the viscoelastic properties (clot impedance on a vibrating probe) of plasma as it is recalcified. Platelet poor plasma (PPP) and platelet rich plasma (PRP) show distinct and characteristic Sonoclot tracings. Tracings of PPP show a lag period and a primary wave. These parameters correspond to recalcification time and fibrin polymerization. Tracings of PRP show, in addition, a secondary wave and a downward wave. These parameters correspond to the incorporation of platelets in the clot and retraction of the clot. The PRP parameters are influenced by the number and quality of the platelets. This instrument was utilized to assess the platelet function in patients after coronary artery bypass surgery (CAB). In 69 patients studied, 20 patients did not have excessive bleeding. The clot impedance tracings in this group were normal. Twenty-four patients had excessive bleeding, normal clot impedance, and coagulation tests indicating the possibility of surgical bleeding. This was confirmed in 22 (92 percent) patients upon exploration to control bleeding. Twenty-five patients had excessive bleeding, normal coagulation tests and abnormal clot impedance suggesting platelet dysfunction. In twenty-one (84 percent) of the patients, transfusion of platelet concentrate controlled the bleeding with corresponding correction of clot impedance. Sonoclot studies are quick and easy to perform, and appear to be a valuable and reliable adjunct in the diagnosis of hemostatic problems after CAB surgery.

Myelopathy following cervical spine manipulation

Manipulation of the spine, a controversial mechanotherapeutic procedure, has been taught and practiced widely. Occlusion of vertebral, basillar, and cerebellar arteries with head and neck manipulation is well documented in the literature. However, there is a paucity of references about myelopathy associated with cervical spine manipulation. Three cases of cervical myelopathy following spinal manipulation are presented. All patients noted increase in cervical pain following manipulation, developed significant sensary/motor deficits within 24 hours and became tetraparetic. Two patients were found to have fracture of C5 and C6 vertebral bodies. On myelography, partial block was noted in all and widening of the spinal cord was noted in two. One patient underwent excision of C5 vertebral body and anterior interbody fusion C4/6. Two patients underwent cervical laminectomy. Hematomyelia was present in one, and in the other patient the spinal cord was reported to be hyperemic and oedematous. Only one patient showed neurological return and became ambulatory, while the other two remained tetraparetic.

Erythroleukemia: a study of 15 cases and literature review

Out of a total of 185 cases of acute leukemia at our institution from 1967 to 1978, fifteen cases (8.1%) were identified as erythroleukemia or erythremic myelosis. The symptoms at presentation were often related to anemia (10/15 cases); the presenting hemoglobin value was lower than 10.0 gm/100 ml. Nucleated red cells were present in the peripheral blood and reticulocyte response was inappropriate to the degree of anemia. Marrow biopsy showed erythroid hyperplasia with megaloblastic and dyserythropoietic features, increase in myeloblasts greater than 5% (10/15 cases), positive PAS staining of erythroid precursors (12/12 cases), and erythrophagocytosis by abnormal erythroid precursors (6/15 cases). Abnormalities were noted in monocytic and megakaryocytic cell lines, and it was concluded that erythroleukemia is probably a stem cell disorder. Response to chemotherapy was poor with median survival of four months from initial diagnosis. Intracranial hemorrhage and bacterial or fungal infection were the most frequent cause of death.

Enzyme labeled immunosorbant assay (ELISA) for detection of platelet antibodies

Although it is widely accepted that patients with immune thrombocytopenia produce platelet antibodies, the demonstration of such antibodies has been difficult and time consuming. A simple and quick enzyme linked immunoassay for platelet antibodies is presented. The platelet associated IgG is coupled with alkaline phosphatase labeled anti-IgG. The resultant complex is determined spectrophotometrically using p-nitrophenyl phosphate as substrate. With this technique, excess of IgG on platelets was detected in 24 out of 33 patients (72 percent) with immune thrombocytopenic purpura and four out of four thrombocytopenic patients with systemic lupus erythematosus. The results of this assay correlate quantitatively with Dixon er al3 complement lysis inhibition assay (r = 0.82).

Prognostic factors and treatment effects on survival in erythroleukemia: a retrospective study of 134 cases

A total of 134 cases of erythroleukemia (119 from the literature and 15 of the authors' patients) were reviewed in an attempt to correlate survival with age, sex, hepatomegaly, splenomegaly, lymphadenopathy, infection, or hemorrhagic complications at initial presentation; hemoglobin (Hgb), white blood cell (WBC) count, and platelet count; percent myeloblasts in the marrow at diagnosis; and treatment regimens employed. Statistical methods included single classification analysis of variance, nonparametric analysis of variance (Kruskal-Wallis method), contingency table analysis, and correlation coefficient determination for numerical data. No significant correlation between survival and age, sex, hepatomegaly, lymphadenopathy, infection, or hemorrhagic phenomena was found. Improved survival was noted in patients without splenomegaly, and in daunorubicin-treated cases in contrast to those treated with other chemotherapeutic agents. A positive correlation between survival and initial Hgb and WBC was also noted. Erythroleukemia complicating a chronic myeloproliferative disorder had a worse prognosis than de novo erythroleukemia.