Post-transfusion purpura (PTP) with severe thrombocytopenia occurred eight days after transfusion in a 28-year-old woman and responded to treatment with prednisone and plasma exchange. In contrast to nearly all previously studied cases of PTP, the patient's platelets were PlA1-positive and anti-PlA1 antibody could not be detected in serum obtained during the thrombocytopenic episode. Her serum was found to contain an antibody specific for a recently described platelet-specific alloantigen, Baka, in addition to multiple HLA-specific antibodies. The patient's platelets, typed following recovery, were Baka-negative. These findings indicate that post-transfusion purpura can occur in association with alloimmunization to platelet-specific antigens other than PlA1. In performing the serologic studies, a close relationship and possible identity between Baka and another recently reported platelet antigen, Leka, was observed. A method for analyzing mixtures of cytotoxic platelet-reactive antibodies without separating the individual antibodies is described.

SUMMARY Thrombocytopenia in cirrhotic patients is usually attributed to splenic pooling whereas in idiopathic thrombocytopenic purpura it is related to platelet bound immunoglobulin (PA-IgG). Since primary biliary cirrhosis (PBC) is an autoimmune disorder we have undertaken a prospective study to assess the frequency and possible relationship of PA-IgG to thrombocytopenia in this condition. Sixty two primary biliary cirrhosis patients (28 precirrhotic; 34 cirrhotic) were studied. Twenty five patients (40%) had raised PA-IgG of whom 18 had cirrhosis. There was a significant inverse correlation between platelet count and PA-IgG (p

An infant with severe neonatal alloimmune thrombocytopenia is described in whom an antibody directed at a new platelet-specific alloantigen, Ca (HPA-6b), is implicated. The new alloantigen is of low frequency in the population and was localized to platelet glycoprotein (GP) IIIa. Immunoprecipitation studies using murine monoclonal antibodies specific for the GP complex IIb-IIIa and GPIIIa alone (AP2 and AP3) suggest that the location of the Ca epitope on GPIIIa may be near the binding site for AP3. Neonatal alloimmune thrombocytopenia associated with Ca is likely to be as severe as that seen in cases due to incompatibilities for the HPA-1 (PIA) and HPA-4 (Pen) platelet alloantigen systems, because each is located on GPIIIa, a densely represented molecule on the platelet surface.

Posttransfusion purpura (PTP) and severe thrombocytopenia occurred 9 days after transfusion of red blood cells to a 48-year-old, multiparous Navajo woman. The platelet count rose to hemostatic levels after treatment with prednisone and three plasma exchange transfusions. Serologic studies showed that the patient's serum contained the potent antibody reactive with platelets from nearly all normal subjects, but nonreactive with autologous platelets obtained after recovery. This antibody was found to be specific for a high-frequency, platelet-specific antigen, designated Pen(a),implicated previously as an immunogen in neonatal alloimmune thrombocytopenic purpura. An exchange of serum showed that Pena is identical with an alloantigen designated Yuk(b) by Japanese workers. We conclude that PTP can occur in association with alloimmunization against Pen(a) (Yuk(b).

After intravenous injection of a single dose of 2.0 g cefpirome (HR 810) and multiple doses of 2.0 g b.i.d. (11 doses) to 10 healthy male volunteers in an open design, concentrations of unchanged drug were measured at various times in serum and urine over 24 and 96 h, respectively. Cefpirome concentrations were determined using high-pressure liquid chromatography (HPLC). The biological half-life (t_½,β) found by fitting a two-compartment open model to the data was 2 h. No accumulation of the serum levels could be detected during the multiple-dose phase. Urinary concentrations of unchanged cefpirome effective against most clinically relevant bacteria were detected for at least 36 h. The drug was safe and well tolerated. No drug-related changes were observed for blood pressure, heart rate, ECG, haematology, clinical chemistry or urinalysis, including β₂-microglobulin in serum and creatinine clearance.