A survey of pediatric malignancy in West Virginia.

The occurrence of malignancy in the pediatric age group is an uncommon but serious event. Since little data are available on the extent, nature or referral patterns of childhood cancer in West Virginia, we conducted a survey of 782 primary care physicians and 17 regional referral centers. The results showed that 249 cases of malignancy in the pediatric age group were reported and that 68% of children with newly diagnosed childhood malignancy were referred to institutions within West Virginia. We conclude that the incidence and distribution of types of malignancy in childhood in West Virginia parallels that of the nation, although there is some regional variation within the state.

An unusual histiocytic disorder responding to cyclosporine therapy: a case report.

PURPOSE: To describe the clinical and pathologic presentation and course of a 7-week-old girl with anemia, thrombocytopenia, and organomegaly who was found to have a histiocytic disorder distinct from previously reported cases. METHODS: Bone marrow specimens were studied with conventional methods. A liver biopsy specimen was evaluated by routine and immunohistochemical methods and electron microscopy. RESULTS: The patient was found to have a unique histiocytic disorder in which lesional cells displayed an atypical phenotype. Cyclosporine therapy was associated with a prompt, complete, and apparently permanent resolution of disease. CONCLUSION: This case appears to represent an atypical histiocytic disorder with unique clinical and pathologic features. The disorder resolved after the initiation of cyclosporine therapy.

The use of heparinase to neutralize residual heparin in blood samples drawn through pediatric indwelling central venous catheters.

Routine-coagulation screening is unreliable if obtained through a previously heparinized central venous catheter. Screening tests were performed on 14 paired peripheral and central venous catheter samples without and with heparinase. The heparinase treated central venous catheter samples correlated well with the peripheral samples and can be used to atraumatically screen for hemostatic abnormalities.

Curing children with leukemia in West Virginia.

Leukemia is the most common cancer in childhood with acute lymphoblastic leukemia (ALL) the most common subtype. While once uniformly fatal, today leukemia is a highly curable disease. To determine the outcomes of children with acute lymphoblastic leukemia in West Virginia, we performed a retrospective analysis of the results of treatment of children and adolescents with B-lineage ALL diagnosed between 2/86 and 1/91 and treated by the pediatric oncology teams at Morgantown or Charleston. Forty-one children with B-lineage ALL were identified and treated by a uniform protocol. Twenty-nine (71%) have remained disease-free for more than two years off therapy and are considered cured. Of the 10 patients who relapsed, five have now been off rescue therapy for greater than two years and are likely to be cured. Thirty-five of the original cohort of 41 children are alive and disease-free yielding an overall survival of 85%. The results of treatment of childhood leukemia in West Virginia are comparable to national data. Children with ALL diagnosed and treated by pediatric oncology teams in West Virginia have a very good chance of being cured.

Elevated levels of tumor necrosis factor-beta, gamma-interferon, and IL-6 mRNA in Castleman's disease.

Castleman's disease (CD) is a lymphoproliferative disorder characterized by enlarged hyperplastic lymph nodes. CD may be localized or multifocal, and is often associated with signs and symptoms of generalized inflammation. The systemic manifestations of CD have been previously attributed to an overproduction of interleukin-6 (IL-6) by the tumor, although there is evidence that IL-6 is not responsible for all of the symptoms. We describe a 9-year-old boy who developed Castleman's disease with systemic findings of hypochromic microcytic anemia, growth arrest, inflammation, and hyperimmunoglobulinemia. Following surgical resection, all of the symptoms and laboratory abnormalities resolved. Using reverse transcriptase polymerase chain reaction (RT-PCR) analysis of the tumor, we found elevated levels of IL-6 mRNA as expected, but also elevated levels of tumor necrosis factor beta (TNF-beta) and gamma interferon (gamma-IFN) mRNA. Because these cytokines are mediators of immune regulation and inflammation, we propose that TNF-beta and gamma-IFN also play an important role in the pathophysiology of Castleman's disease.

Thrombin-catalyzed activation of recombinant human factor V.

Proteolytic activation of human factor V by thrombin results from the cleavage of three peptide bonds at Arg709, Arg1018, and Arg1545. In order to define the functional importance of these sites, mutants with isoleucine substitutions blocking thrombin cleavage at one, two, or all three activation sites were expressed in COS-7 cells. The wild type protein is activated approximately 10-fold by thrombin or Russell's viper venom (RVV-V). Thrombin cleavage at Arg709 alone did not result in an increase in procoagulant activity. Cleavage at both Arg709 and Arg1018 resulted in an approximately 3.4-fold increase in activity. Cleavage at these sites was required for rapid cleavage by thrombin at Arg1545, however, which resulted in maximal activation of the factor V molecule. In contrast, isolated cleavage at Arg1545 by RVV-V was sufficient for efficient and complete activation of factor V. The effect of isoleucine substitutions at one or both thrombin cleavage sites in a B-domain deletion mutant lacking amino acids 811-1491 was also investigated. The specific activity of all four mutants was approximately 30% compared to thrombin activated factor V, indicating that these isoleucine substitutions do not drastically alter the structure of the protein and that cleavage at these sites is not required for the expression of partial procoagulant activity.

Disseminated histoplasmosis: a cause of infection-associated hemophagocytic syndrome.

PURPOSE: We report a case of infection-associated hemophagocytic syndrome in the setting of disseminated histoplasmosis. PATIENTS AND METHODS: A 6-year-old boy with chronic mucocutaneous candidiasis developed a fulminant hemophagocytic syndrome. Evaluation for an infectious cause included bacterial, mycobacterial, viral, and fungal cultures, serological assessment, and histological examination of bone marrow and bronchoalveolar lavage fluid. RESULTS: Culture of bone marrow aspirate, blood, and bronchoalveolar lavage showed disseminated histoplasmosis as the cause for this patient's hemophagocytic syndrome. The patient was treated with amphotericin B with complete resolution of his hemophagocytic syndrome. CONCLUSIONS: Disseminated histoplasmosis is another cause of IAHS in children with an underlying immunodeficiency. Diagnostic difficulties associated with the hemophagocytic syndromes of childhood are discussed.

Localization of functionally important epitopes within the second C-type domain of coagulation factor V using recombinant chimeras.

Coagulation factor V, an integral component of the prothrombinase complex, possesses two C-type domains at the carboxyl-terminal end of the molecule. Homologous C-type domains are present in factor VIII as well as several non-coagulation proteins. Deletion of the second C-type domain of factor V results in the loss of procoagulant activity and the ability to bind phosphatidylserine. We now report the effect of substitution of all or a portion of the C2 domain of factor V with the corresponding regions of factor VIII or the human breast carcinoma protein BA46. Substitution of the entire domain with a heterologous C2 domain does not restore significant procoagulant activity, although smaller, exon-size substitutions do result in chimeras with partial activity (approximately 10% of factor Va). Using chimeras with partial substitutions, we determined that the amino-terminal region of the domain is involved in binding to phosphatidylserine. In contrast, the central region of the domain is not involved in phosphatidylserine binding, but an antibody binding at or near this site inhibits procoagulant activity, suggesting that this region is involved in a separate function. Lastly, the molecular basis for the light chain doublet, which is important in the expression of full procoagulant activity, is located within the carboxyl-terminal region of the C2 domain.

Topical thrombin and acquired coagulation factor inhibitors: clinical spectrum and laboratory diagnosis.

Topical bovine thrombin preparations are used extensively in cardiovascular, neurosurgical, and otolaryngologic procedures. Patients who are treated with these topical thrombin preparations may develop antibodies to bovine coagulation factors that may cross-react with the endogenous human clotting proteins. We have identified four patients with acquired factor inhibitors following exposure to topical thrombin at Duke University Medical Center and summarize these cases in addition to 13 patients previously reported in the literature. In most cases, the inhibitor developed following a second (or subsequent) exposure to topical thrombin. The clinical course was extremely variable, ranging from totally asymptomatic to life-threatening hemorrhage. The most consistent laboratory abnormality was a prolonged bovine thrombin clotting time, which corrected, at least partially, when human thrombin was substituted for bovine thrombin. Some of these patients also developed factor V inhibitors with prolonged prothrombin and activated partial thromboplastin times. Although these patients have prolonged clotting times, they should not be considered "autoanticoagulated," since thromboembolic complications can still occur. Therapeutic intervention is largely empirical and depends on the clinical manifestations of the individual patient.