[show abstract][hide abstract] ABSTRACT: Multicenter trials in Southeast Asia have shown better survival rates among patients with severe malaria, particularly those with high parasitemia levels, treated with intravenous (IV) artesunate than among those treated with quinine. In Europe, quinine is still the primary treatment for severe malaria. We conducted a retrospective analysis for 25 travelers with severe malaria who returned from malaria-endemic regions and were treated at 7 centers in Europe. All patients survived. Treatment with IV artesunate rapidly reduced parasitemia levels. In 6 patients at 5 treatment centers, a self-limiting episode of unexplained hemolysis occurred after reduction of parasitemia levels. Five patients required a blood transfusion. Patients with posttreatment hemolysis had received higher doses of IV artesunate than patients without hemolysis. IV artesunate was an effective alternative to quinine for treatment of malaria patients in Europe. Patients should be monitored for signs of hemolysis, especially after parasitologic cure.
[show abstract][hide abstract] ABSTRACT: The Dombrock (Do) blood group system consists of five distinct antigens: Do(a), Do(b), Gy(a), Hy, and Jo(a). Our finding of a patient whose plasma contained a Do-related alloantibody suggested the presence of a sixth antigen.
Standard hemagglutination, flow cytometry, and polymerase chain reaction (PCR)-based methods were used throughout. Protein homology modeling was used to map the amino acid change on the protein structure.
The patient's red blood cells (RBCs) typed as Do(a-b-), Hy+(w), Jo(a+(w)), and Gy(a+(w)). The patient's plasma agglutinated RBCs with common Dombrock phenotypes. Reactivity with Hy- and Jo(a-) RBC samples was weak, and Gy(a-) RBC samples were nonreactive. DNA analysis showed the patient to be DO*793A (DO*A/DO*A), DO*323G, and DO*350C, which predicts the Do(a+b-), Hy+, and Jo(a+) phenotype, and revealed a homozygous single-nucleotide change of 547T>G in Exon 2 that is predicted to change tyrosine at Amino Acid Position 183 to aspartic acid. This missense substitution introduced a BtgZI restriction enzyme site. The sequence data were confirmed with a PCR-restriction fragment length polymorphism assay and revealed that the patient's parents and children were heterozygous DO*547T/G. Homology modeling predicted that the 183Tyr substitution by Asp altered the Cys182 environment and influenced the formation and/or stability of the Cys182-Cys231 disulfide bond.
The patient's DO genes have a single-nucleotide change, which leads to the absence of the high-prevalence antigen DOYA. The absence of this antigen is associated with 183Asp and silencing of Do(a) and weakening of Gy(a), Hy, and Jo(a) antigens.
[show abstract][hide abstract] ABSTRACT: In this study, the data of eight new patients in conjunction with previously reported cases with piperacillin-induced immune hemolytic anemia (PIHA) are described.
Five patients with cystic fibrosis and three patients with other disorders developed massive hemolysis after administration of piperacillin. Serologic tests were carried out using standard techniques. Tests for drug-dependent antibodies (ddab) were performed in the presence and absence of piperacillin and its ex vivo antigens (urine of patients treated with piperacillin).
Hemolysis was acute and severe in all eight patients. The direct antiglobulin test was positive in all cases. Sera from four patients reacted with red blood cells (RBCs) in the presence of piperacillin as well as its ex vivo antigens. Sera from three patients showed positive reactivity with untreated RBCs in the presence of piperacillin, and the serum from the remaining patient was reactive only in the presence of piperacillin ex vivo antigens. Other patients with PIHA have been reported in the literature. Three of these patients also had cystic fibrosis.
To date approximately 26 patients with PIHA have been described and at least eight of these patients had cystic fibrosis. It is unclear whether patients with cystic fibrosis might be susceptible in developing PIHA.
[show abstract][hide abstract] ABSTRACT: Autoimmune hemolytic anemia (AIHA) is usually classified as either warm or cold type. During the past few decades, mixed types (Mxs) have also been described in a number of cases (6%-8% of AIHA), often without serologic data to support the diagnosis. In this study, we demonstrate that the incidence of Mx AIHA in our institution is extremely rare.
Between August 1998 and August 2007, all in- and outpatients with detectable warm autoantibodies (WABs) were included in this study. Serologic testing was performed using standard techniques for the detection of red blood cell antibodies.
From a total of 2194 patients with detectable WABs, only 2 patients (<0.1%) developed both WABs and cold agglutinins (CAs), which in the presence of clinical evidence of hemolytic anemia, satisfies the criteria for Mx AIHA. Only 1 of these patients, however, showed cold and warm hemolysis. Insignificant CAs at temperatures of not more than 24 degrees C were found in 242 patients.
There is evidence that the presence of CAs with high thermal amplitude and WABs may lead to confusion and misdiagnosis in some patients with AIHA. This study demonstrates that Mx AIHA is less common than previously reported.