RESUMO

OBJECTIVE: Fetal and neonatal alloimmune thrombocytopenia (AIT) caused by feto-maternal incompatibility at the HPA-1a (PLA-1) locus is well characterized. Alloimmunization and disease caused by HPA-3a is rare. STUDY DESIGN: We conducted a retrospective analysis of all known cases of AIT caused by HPA-3a incompatibility identified at 3 major reference laboratories from 1986 to 1996. Platelet antigen typing and antibody specificity were determined by serologic evaluation. In some cases confirmatory genotyping was performed. RESULTS: Fourteen cases of anti-HPA-3a-induced AIT in 11 families were identified. Five patients had a previous affected sibling, and 2 cases were firstborn children. All patients had severe thrombocytopenia at birth (platelet count <20 x 10(9)/L). Regardless of therapy, the median time to platelet recovery was 6 days (range, 3 to 23 days). Two (15%) patients had documented intracranial hemorrhage, 1 with severe sequelae including apnea and convulsions. A literature review describing 16 additional patients corroborates the finding of severe thrombocytopenia and a significant incidence of intracranial hemorrhage caused by HPA-3a incompatibility. CONCLUSION: AIT caused by incompatibility of HPA-3a is similar in severity to disease caused by incompatibility of HPA-1a. Affected families should be appropriately counseled and considered for antenatal therapy.

Assuntos

RESUMO

OBJECTIVE: To assess the role of granulocyte colony-stimulating factor (G-CSF) in autoimmune neutropenia (AIN). DESIGN: Serum G-CSF levels were measured in 57 children with AIN. Two different G-CSF-dependent assays were used: a solid-phase "sandwich" enzyme-linked immunosorbent assay and a proliferation assay. Sera from healthy persons and from patients with severe congenital neutropenia were used for negative and positive controls. RESULTS: The median G-CSF level in healthy persons (n = 13) was low, 45.6 pg/mL (range <39 to 141 pg/mL). The median G-CSF level in patients with AIN (n = 57) was very similar, 45.5 pg/mL (range <39 to 2500 pg/mL). Forty-five (79%) of 57 patients with AIN had levels within the range of the control group. Seven (12%) had marginally increased G-CSF levels (141 to 400 pg/mL), and only 5 (9%) had levels higher than 400 pg/mL. The G-CSF levels measured by enzyme-linked immunosorbent assay correlated well with levels measured by the proliferation assay, thus demonstrating that antibodies present in patient sera did not affect the biologic activity of G-CSF. CONCLUSION: G-CSF production in AIN is not increased despite the low neutrophil count, similar to thrombopoietin in immune thrombocytopenic purpura.

Assuntos

Assuntos

RESUMO

Bilateral renal enlargement was noted on ultrasonography during an extensive renal evaluation for severe hypokalemic metabolic acidosis with an increased anion gap in a 12-year-old Hispanic boy who had normal results of a physical examination and complete blood count. The patient was found to have acute lymphoblastic leukemia. Resolution of the lactic acidosis and bilateral renal enlargement occurred with initiation of chemotherapy and recurred with each subsequent relapse.

Assuntos

Assuntos

RESUMO

Infusions of intravenous gamma-globulin (IVGG) are an effective, nontoxic therapy for chronic idiopathic thrombocytopenic purpura (ITP) that would be more widely accepted if the therapeutic agent were not so expensive. The costs and outcomes of managing such children with splenectomy and IVGG were modeled with Markov processes. Children unresponsive to one treatment were considered to have received the alternative. The model accounted for spontaneous remissions, therapeutic responses, traumatic events, episodes of sepsis, and operative deaths. For a 10-year-old child with chronic ITP, the strategy of initial treatment with splenectomy had associated costs of $17,000 and a 97.9% ten-year survival rate, whereas the strategy of initial treatment with IVGG had associated costs of $21,000 but a 98.6% survival rate. Each additional life saved by employing the IVGG strategy cost $540,000, or $8,000 per year for a life expectancy of 70 years. Sensitivity analyses demonstrated that for older children the IVGG strategy continued to result in improved survival rates but was more costly than the splenectomy strategy. For younger children, the IVGG strategy dominated, with improved survival rates and lower costs.

Assuntos

Assuntos

RESUMO

Gammaglobulin treatment was given at a dose of 1 gm/kg/day intravenously in 29 patients with acute idiopathic thrombocytopenic purpura: 15 previously untreated, 10 resistant to steroids, and four who were steroid dependent. The average platelet increase in 24 hours was greater than 50,000/microliter; the average peak platelet count was 194,000/microliter. Eighteen of 25 patients required only one infusion; 10 of these 18 never required any additional (maintenance) therapy. Outcome in previously untreated and steroid-resistant patients was identical; however, previously untreated patients required only 1.8 gm/kg total dose of gammaglobulin, whereas steroid-resistant patients received 3.9 gm/kg. Only one steroid-dependent child of the 29 patients still requires maintenance therapy, at 6-week intervals. Toxicity was minimal. Cost was minimized by not admitting patients and by giving treatment in one visit, rather than five.

Assuntos

RESUMO

Intravenous gammaglobulin was used to treat 12 children with chronic immune thrombocytopenic purpura in order to avoid splenectomy. The average rise in platelet count with initial treatment was 226,000/microliters. Currently, one patient is in remission, four patients maintain platelet counts greater than 40,000/microliters without treatment, four patients maintain platelet counts greater than 40,000/microliters with single maintenance infusions of IV IgG at four- or 10-week intervals; three patients did not respond to treatment. In nine of 12 patients, splenectomy was avoided or at least postponed. In responding patients, we were able to discontinue immunosuppressive medication. Platelet count rises with initial IV IgG therapy were correlated with both platelet antibody levels and with a better long-term outcome. Toxicity was minimal.

Assuntos