Biomedical subjects

Kelty R Baker

Publications and source records attributed to Kelty R Baker.

4 recordsLinked to original sources

PubMed2006

Current management of the myeloproliferative disorders: a case-based review.

CONTEXT: Properly managed, the myeloproliferative disorders are generally compatible with prolonged survival. Challenges to the hematologist include knowing when and how best to intervene to prevent and manage complications. The cytoreductive agent of choice for these disorders is currently hydroxyurea, emerging from randomized trials beginning with those of the Polycythemia Vera Study Group. OBJECTIVE: To examine the roles and shortcomings of interventions (including hydroxyurea, antiplatelet agents, anagrelide, interferon, thalidomide, alkylating agents, cell cytopheresis, erythropoietins, splenectomy, bone marrow transplantation, and imatinib) for myeloproliferative disorders. DATA SOURCES: This report uses actual case histories to illustrate the roles and shortcomings of these interventions. CONCLUSIONS: Beyond phlebotomy for polycythemia vera, patients with polycythemia vera and essential thrombocythemia can be stratified by their risk for thrombosis, which guides the institution of cytoreductive therapies. High-risk patients generally benefit from cytoreductive therapy, and hydroxyurea has emerged as the agent of choice, because alkylating agents (and P32) have high leukemogenic potentials. Anagrelide and interferon are second-line agents. The addition of low-dose aspirin is beneficial for most, helping to prevent arterial thrombotic complications. Therapy in any of these disorders should be tailored to the unique characteristics of the individual patient. With myelofibrosis, therapeutic options run the gamut from observation, erythropoietic stimulators, cytotoxic agents, splenectomy, and bone marrow transplantation. Thalidomide and imatinib have shown some utility. Future challenges are the refinement of individualized treatment strategies and the development of targeted therapies based on rapidly expanding understanding of the molecular perturbations in these disorders.

Adult↗

PubMed2004

Warfarin-induced skin necrosis and venous limb gangrene in the setting of heparin-induced thrombocytopenia.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a common, often catastrophic, syndrome that produces the most hypercoagulable of states. Emerging therapeutic strategies use alternative anticoagulants; warfarin's place is being reexamined. Early in the course of warfarin therapy, there may be net procoagulant effects because of the inhibition of protein C. With HIT, it has been suggested that unopposed warfarin can precipitate venous limb gangrene. There are also reports of warfarin-induced skin necrosis. We seek to confirm and increase awareness of the risks of warfarin with HIT. METHODS: We describe 6 patients with HIT seen at 3 medical centers in whom frank or impending venous limb gangrene, central skin necrosis, or both were temporally related to warfarin initiation. RESULTS: At warfarin initiation, 5 patients had recognized HIT and 1 had it recognized later. Complications emerged after 2 to 7 days, and consisted of warfarin-induced skin necrosis (n = 5) and venous limb gangrene (n = 2); 1 patient had both. This emerged with unopposed warfarin in 4 patients and as a direct thrombin inhibitor was being withdrawn in 2. All had supratherapeutic international normalized ratios. One patient required leg and breast amputations, and another one died. CONCLUSIONS: Because of the early effects on protein C, warfarin can precipitate venous limb gangrene and/or skin necrosis in the extreme hypercoagulable milieu of HIT. With HIT, unopposed warfarin should be avoided and caution is needed during transition from a direct thrombin inhibitor. Warfarin should be initiated at modest doses in patients with HIT after platelet recovery. Implications extend to warfarin initiation with other thrombotic diatheses.

Adult↗

PubMed2003

Laparoscopic splenectomy for chronic recurrent thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is a serious hematologic disorder with a high rate of morbidity and mortality when it fails to go into remission. The primary treatment is total plasma exchange. The addition of corticosteroids, chemotherapeutic agents, or antiplatelet agents is of unproven benefit, and splenectomy has been offered as salvage therapy in refractory cases. We performed laparoscopic splenectomy (LS) on two patients with chronic refractory TTP. The early and late postoperative courses, including hematologic data, are presented here. The mean duration of surgery was 113 minutes and the mean estimated blood loss was 35 mL. Mean hospital stay was 1.5 days. The early postoperative platelet count showed an immediate rise in both patients. After 19 months and 16 months of follow-up, respectively, both patients remain in remission without further episodes of TTP. Laparoscopic splenectomy is a safe and effective therapy for patients with chronic relapsing and refractory TTP. The inherent benefits of the minimally invasive approach, its low morbidity, short hospital stay, and faster recovery, are significant advantages for these patients.

Adult↗

PubMed2003

Human immunodeficiency virus hematology.

The advent of potent antiretroviral therapy has altered the expected natural history of human immunodeficiency virus (HIV) infection and of many previously associated opportunistic complications, including malignancies. At the same time, HIV suppression has not affected all of these complications equally and the longer expected survival of infected patients may allow the development of newer complications. Additionally, the use of potent antiretroviral combination therapy may itself lead to hematological toxicities. Together these changes affect the consultation role of the hematology-oncology specialist in comprehensive HIV care and demand ongoing education. In Section I, Dr. Paul Volberding reviews the biology of antiretroviral drug development and the progression in discovering new agents as the viral life cycle is further elucidated. He briefly summarizes the process of combining agents to achieve the degree of viral suppression required for long-term clinical benefit. In Section II, Dr. Kelty Baker reviews the effects of HIV and its therapy on hematologic dyscrasia and clotting disorders. She summarizes how therapy may decrease certain previously common manifestations of HIV disease while adding new problems likely to result in referral to the hematologist. In addition, she addresses the role of secondary infections, such as parvovirus, in this spectrum of disorders. In Section III, Dr. Alexandra Levine discusses the still challenging aspects of HIV associated non-Hodgkin's lymphoma and the association between HIV infection and Hodgkin's disease. She addresses current controversies in the pathogenesis of HIV related lymphomas and summarizes a number of recent trials of combination chemotherapy, with or without monoclonal antibodies, in their management. Additionally, she reviews the complex relationship of HIV disease with multicentric Castleman's disease and recent attempts to manage this disorder.

Anti-Retroviral Agents↗