Treatment of Congenital Thrombotic Thrombocytopenia Purpura: A New Paradigm.

Congenital thrombotic thrombocytopenia purpura (cTTP) is a very rare disorder worldwide. Standard treatment of recognized cases has been to administer fresh frozen plasma as the source of ADAMTS13, to replenish the absent ADAMTS13 enzyme. An alternative source, a plasma-derived factor VIII concentrate used for hemophilia A, and found to contain this enzyme, was reported to be effective in 1 patient in the United States. We now report details on a US cohort of 8 cTTP patients who have been successfully treated for varying periods with a marketed antihemophilic factor concentrate Koate-DVI. This biological product has been used successfully on demand in varying doses to treat acute exacerbations, as well as prophylactically (3 to 6 U ADAMTS13 every 3 to 21 d). Self-infused at home, in lieu of fresh frozen plasma therapy in the hospital setting, this product has effectively prevented episodes of thrombocytopenia, microangiopathic hemolytic anemia, and the concomitant organ damage in these patients. This specific virus inactivated product can be used to prevent further manifestations of this congenital enzyme deficiency.

Recurrent orthostatic global amnesia in a patient with postoperative hyperfibrinogenemia.

Transient global amnesia (TGA) is characterized by sudden, temporary dysfunction of antegrade and recent retrograde memory without other neurologic deficits. Although there is sometimes a precipitating event, the origin of TGA remains controversial. We encountered a patient who developed recurrent TGA when upright, in whom the symptom promptly and regularly resolved when supine. Symptoms began about a week after cardiac surgery concurrent with marked hyperfibrinogenemia and acceleration of the erythrocyte sedimentation rate, and abated without recurrence when these laboratory abnormalities were ameliorated by anticoagulant and corticosteroid therapy. Diagnostic studies, including temporal artery biopsy and cerebral angiography, disclosed no anatomic vascular pathology. This is the first report of TGA associated with postoperative inflammation in which amnesia was provoked by orthostatic positioning. In conclusion, these observations implicate ischemia caused by hemodynamic vascular insufficiency as a possible cause of TGA.

Efficacy of romiplostim in patients with chronic immune thrombocytopenic purpura: a double-blind randomised controlled trial.

BACKGROUND: Chronic immune thrombocytopenic purpura (ITP) is characterised by accelerated platelet destruction and decreased platelet production. Short-term administration of the thrombopoiesis-stimulating protein, romiplostim, has been shown to increase platelet counts in most patients with chronic ITP. We assessed the long-term administration of romiplostim in splenectomised and non-splenectomised patients with ITP. METHODS: In two parallel trials, 63 splenectomised and 62 non-splenectomised patients with ITP and a mean of three platelet counts 30x10(9)/L or less were randomly assigned 2:1 to subcutaneous injections of romiplostim (n=42 in splenectomised study and n=41 in non-splenectomised study) or placebo (n=21 in both studies) every week for 24 weeks. Doses of study drug were adjusted to maintain platelet counts of 50x10(9)/L to 200x10(9)/L. The primary objectives were to assess the efficacy of romiplostim as measured by a durable platelet response (platelet count > or =50x10(9)/L during 6 or more of the last 8 weeks of treatment) and treatment safety. Analysis was per protocol. These studies are registered with ClinicalTrials.gov, numbers NCT00102323 and NCT00102336. FINDINGS: A durable platelet response was achieved by 16 of 42 splenectomised patients given romplostim versus none of 21 given placebo (difference in proportion of patients responding 38% [95% CI 23.4-52.8], p=0.0013), and by 25 of 41 non-splenectomised patients given romplostim versus one of 21 given placebo (56% [38.7-73.7], p<0.0001). The overall platelet response rate (either durable or transient platelet response) was noted in 88% (36/41) of non-splenectomised and 79% (33/42) of splenectomised patients given romiplostim compared with 14% (three of 21) of non-splenectomised and no splenectomised patients given placebo (p<0.0001). Patients given romiplostim achieved platelet counts of 50x10(9)/L or more on a mean of 13.8 (SE 0.9) weeks (mean 12.3 [1.2] weeks in splenectomised group vs 15.2 [1.2] weeks in non-splenectomised group) compared with 0.8 (0.4) weeks for those given placebo (0.2 [0.1] weeks vs 1.3 [0.8] weeks). 87% (20/23) of patients given romiplostim (12/12 splenectomised and eight of 11 non-splenectomised patients) reduced or discontinued concurrent therapy compared with 38% (six of 16) of those given placebo (one of six splenectomised and five of ten non-splenectomised patients). Adverse events were much the same in patients given romiplostim and placebo. No antibodies against romiplostim or thrombopoietin were detected. INTERPRETATION: Romiplostim was well tolerated, and increased and maintained platelet counts in splenectomised and non-splenectomised patients with ITP. Many patients were able to reduce or discontinue other ITP medications. Stimulation of platelet production by romiplostim may provide a new therapeutic option for patients with ITP.

AMG 531, a thrombopoiesis-stimulating protein, for chronic ITP.

BACKGROUND: Most current treatments for chronic immune thrombocytopenic purpura (ITP) act by decreasing platelet destruction. In a phase 1-2 study, we administered a thrombopoiesis-stimulating protein, AMG 531, to patients with ITP. METHODS: In phase 1, 24 patients who had received at least one treatment for ITP were assigned to escalating-dose cohorts of 4 patients each and given two identical doses of AMG 531 (0.2 to 10 microg per kilogram of body weight). In phase 2, 21 patients were randomly assigned to receive six weekly subcutaneous injections of AMG 531 (1, 3, or 6 microg per kilogram) or placebo. The primary objective was to assess the safety of AMG 531; the secondary objective was to evaluate platelet counts during and after treatment. RESULTS: No major adverse events that could be attributed directly to AMG 531 occurred during the treatment period; 4 of 41 patients had transient post-treatment worsening of thrombocytopenia. In phase 1, a platelet count that was within the targeted range (50,000 to 450,000 per cubic millimeter) and at least twice the baseline count was achieved in 4 of 12 patients given 3, 6, or 10 mug of AMG 531 per kilogram. Overall, a platelet count of at least 50,000 per cubic millimeter was achieved in 7 of 12 patients, including 3 with counts exceeding 450,000 per cubic millimeter. Increases in the platelet count were dose-dependent; mean peak counts were 163,000, 309,000, and 746,000 per cubic millimeter with 3, 6, and 10 microg of AMG 531 per kilogram [corrected], respectively. In phase 2, the targeted platelet range was achieved in 10 of 16 patients treated with 1 or 3 mug of AMG 531 per kilogram per week for 6 weeks. Mean peak counts were 135,000, 241,000, and 81,000 per cubic millimeter in the groups that received the 1-mug dose, the 3-mug dose, and placebo, respectively. CONCLUSIONS: AMG 531 caused no major adverse events and increased platelet counts in patients with ITP. (ClinicalTrials.gov number, NCT00111475 [ClinicalTrials.gov].).

Echinocytosis--an unusual manifestation of hemangioma.

The case of a 21 year-old female with echinocytosis and a littoral cell hemangioma is reported. The patient had no significant past medical history and presented with abdominal pain and splenomegaly. A large percentage of echinocytes were noted on her peripheral smear in the absence of any known causes. A CT-recognized splenic mass led to splenectomy and a benign hemangioma was found. Red blood cell abnormalities resolved immediately after the surgery. This is the first case reported in the literature of echinocytosis as a consequence of a hemangioma.

Therapeutic choices in the current millennium: hemophilia workshop highlights.

Many issues affect hemophilia care providers when managing bleeding episodes in individuals with hemophilia. A diverse group of hemophilia providers from the United States met at two workshops to discuss the issues influencing treatment choices in the current millennium and to learn about current advances in treatment of hemophilia. This paper provides a summary of the discussions at these workshops. Despite the progress made in the management of patients with hemophilia, the workshop highlighted the fact that there were still many unanswered questions.

Prospective screening of 205 patients with ITP, including diagnosis, serological markers, and the relationship between platelet counts, endogenous thrombopoietin, and circulating antithrombopoietin antibodies.

Immune thrombocytopenia purpura (ITP) is characterized by destruction of circulating platelets and the presence of antiplatelet antibodies. Many of the current immunomodulatory therapies act by reducing platelet destruction and usually do not have a lasting effect. This prospective, exploratory study characterized patients with ITP by identifying their demographic and comorbid clinical factors, use of treatments, serologic markers of autoimmunity, and possible relationships between platelet counts, concentrations of endogenous thrombopoietin (eTPO), and the presence of circulating anti-TPO antibodies. Data including medical history and laboratory evaluations were collected at a single patient visit on 205 patients (19 children, 186 adults). Reported histories revealed a 5% rate of thrombotic/ischemic events. Autoimmune markers including direct antiglobulin test and antinuclear antibodies were found more frequently than in the normal population; antiplatelet antibody testing was not done. eTPO concentrations were comparable to concentrations found in healthy volunteers. Our study confirmed that no significant inverse correlation occurred between circulating concentrations of eTPO and platelet counts in patients with ITP (Spearman r = -0.15). Two of the 205 patients tested (1%) had neutralizing activity of recombinant human TPO in a biological assay; however, this activity was confirmed to be anti-TPO antibody in only 1 patient.

Advances in clotting factor treatment for congenital hemorrhagic disorders.

During the last 50 years, clotting factor replacement has evolved from the use of frozen plasma in the 1950s, through the serendipitous discovery of cryoprecipitate in the 1960s and the development of purified clotting factors in the 1970s and 1980s, to the era of recombinant clotting factors beginning in the 1990s. The dawn of the new millennium has seen the refinement of recombinant factor (rF) VIII with enhanced safety via the elimination of plasma-derived culture media or product stabilizers. During the last decade of the 20th century, a cure for hemophilia through gene therapy became a possibility. This was, in part, facilitated by availability of large (dogs) and small (mice) animal models for hemophilia A and B. Although this review will focus primarily on clotting factor replacement, the reader may refer to recent discourse on gene therapy for hemophilia.

Kaposi's sarcoma-associated herpesvirus infection in elderly Jews and non-Jews from New York City.

BACKGROUND: Worldwide, Kaposi's sarcoma (KS) occurs in immunocompetent elderly adults, especially men. Elderly Jews have relatively high KS risk, but it is unclear whether this indicates heightened prevalence of KS-associated herpesvirus (KSHV), the KS agent. We studied Jewish and non-Jewish patients at a New York City geriatrics clinic. METHODS: We measured plasma antibodies against K8.1 (a KSHV glycoprotein) by enzyme immunoassay and against viral latency antigens by immunofluorescence assay. Individuals positive by either were considered KSHV-seropositive. Titres were performed for positive subjects. We used polymerase chain reaction to quantify circulating KSHV DNA. RESULTS: Of 467 subjects (median age 80 years), 40 were KSHV-seropositive (8.6%). Seroprevalence was 8.8% among Jews (18 of 204), similar to other religious groups, and did not differ by sex or region of birth. However, K8.1 antibody titres were higher in men than women (geometric mean titre 177 versus 35, P = 0.03) and increased with age (P = 0.02). The K8.1 titres were higher in three people from Central/Eastern Europe (1,280, 1,280, 320), all of whom were Jewish, than in others (geometric mean titre 39, P = 0.006). The single person with detectable circulating KSHV (457 copies/million cells) had the highest titre (5,120). CONCLUSIONS: The KSHV seroprevalence was not elevated among elderly Jews, despite their known high risk for KS. However, among KSHV-seropositive individuals, K8.1 titres were highest in subgroups at greatest risk for KS (men, older individuals, people from Central/Eastern Europe) and may identify individuals with poor immune control of KSHV replication during asymptomatic infection.