A survey of the incidence of Miltenberger antibodies among Hong Kong Chinese blood donors

BACKGROUND: The ready availability of red cells of the Miltenberger (Mi) class III phenotype (6.28%) prompted the study of Mi antibodies among Chinese blood donors in Hong Kong, 98 percent of whom are descended from inhabitants of Guangdong Province in southern China. STUDY DESIGN AND METHODS: Red cells of the Mi class III phenotype were used to conduct a survey of the frequency of Miltenberger antibodies in 56,161 random Chinese blood donors, over a period of 12 months, using a microplate technique. RESULTS: Sera from 32 donors (0.057%) were found to contain Mi antibodies: sera from 22 contained anti-Mur + Hut; sera from 4 contained anti-Vw + Mur + Hut; sera from 4 had monospecific anti- Mur; and sera from 2 had monospecific anti-Hil. The immunoglobulin isotypes of 24 sera were mixtures of IgM and IgG, 4 were pure IgM, and 4 were pure IgG. CONCLUSION: The majority of Mi antibodies detected were naturally occurring. This survey proved useful for mass screening of random donors for the procurement of valuable Mi antisera.     

Lupus Nephritis and Pregnancy

Sixty-four pregnancies in 41 women with biopsy proven lupusnephritis between 1965 and 1991 were analysed to record fetaland maternal outcome and identify risk factors for poor outcome.Of 65 fetuses, 22 (34 per cent) were lost (including therapeuticabortions), 19 (30 per cent) were live born but premature (     

A flow cytometric method for phenotyping recipient red cells following transfusion

BACKGROUND: Reticulocyte phenotyping is used for transfused patients, who have red cell antibodies, to match blood for subsequent transfusion. Current methods are labor-intensive and require a significant amount of sample. STUDY DESIGN AND METHODS: A simple dual- color flow cytometry method developed for antigen typing of reticulocytes in mixed red cell populations is reported. Antigens were labeled by an indirect immunofluorescence technique using undiluted reagent sera as the primary label, biotinylated goat anti-human IgG as the secondary label, and avidin-phycoerythrin as the fluorescent stain. Reticulocytes were labeled with a thiazole orange fluorescent stain. Reticulocyte identification and antigen typing were performed on 319 samples to establish the validity of the procedure. Mixed red cells were prepared in all possible c antigen combinations to simulate transfusion concentrations of 25, 50, and 75 percent. RESULTS: The anti- c flow cytometry profiles readily distinguished between antigen- positive and antigen-negative populations and allowed the detection of reticulocytes at all simulated transfusion concentrations. Similar results were obtained in experiments using C, K, s, Fya, Fyb, Jka, or Jkb sera against equal volumes of antigen-positive and -negative cells. Anti-S gave inconsistent results. The in vitro results were confirmed in 19 transfused patients who had received red cells antigenically different from their own as well as cells from 1 chimera blood donor. CONCLUSION: This method provides a simpler, safer, less labor- intensive, and less subjective technique requiring far less sample volume than current methods for antigen typing of reticulocytes in mixed red cell samples from recently transfused patients.     

Activation of the alternative complement pathway with rabbit erythrocytes by circumvention of the regulatory action of endogenous control proteins

Cleavage of C3 by the alternative complement pathway occurs in at least two distinct phases: continuous low grade generation of C3b by the interaction of native C3, B, D, and P, and subsequent amplified cleavage of C3 by the interaction of C3b, B, D, and P which forms the amplification convertase, P,C3b,Bb. Transition to C3b-dependent amplification is necessary to achieve substantial C3 cleavage and is normally limited by the combined action of C3b inactivator (C3bINA) and βlH. An activator of the alternative pathway, such as rabbit erythrocytes (E(r)), provides sites that protect bound C3b and P,C3b,Bb from the action of these regulatory proteins and permits C3b deposited by the low grade fluid phase reaction to assemble a membrane-associated amplification convertase which can deposit additional protected C3b. Under conditions in which the control proteins, C3bINA and β1H, almost completely inactivated C3b bound to sheep erythrocytes (E(s)), which does not activate the alternative pathway, the function of C3b bound to E(r) was diminished by less than one-fifth. Further, the P- stabilized amplification convertase on E(r) was 10-fold less sensitive to β1H-mediated decay-dissociation than the convertase on E(s). The addition of E(r) to a regulated mixture of purified C3, B, D, P, C3bINA, and β1H resulted in amplified inactivation of C3 and B by formation of the amplification convertase on E(r) as indicated by its lysis with subsequent exposure to C3-C9. In contrast, E(s) did not advance the low grade fluid phase inactivation of C3 and B to amplified inactivation and the cell was not converted to an intermediate susceptible to lysis by C3- C9. Since E(r) and E(s) did not differ in their inefficient fixation of C3b generated during an unregulated fluid phase reaction, the activating capacity of E(r) must reside in its protection of bound C3b and P, C3b,Bb from the regulatory proteins rather than in enhanced capacity to bind C3b from the fluid phase. When the reaction is limited to low grade fluid phase turnover, introduction of E(r) but not E(s) results in a 100-fold increase in the deposition of C3b, indicating that surface-dependent activation of the alternative pathway is characterized by efficient deposition of C3b on the initiating surface. Thus, the activating surfaces advance the interaction of the alternative pathway proteins to the amplification phase because of the selective inability of the regulatory proteins to deal with their substrates when deposited on these surfaces and results in a specificity that is not necessarily dependent on adaptive immunity.     

High-dose intravenous gamma globulin improves responses to single-donor platelets in patients refractory to platelet transfusion

Ten patients, with bone marrow failure or malignant disorders, became refractory to platelet transfusions using random, as well as partial or fully HLA-matched, single-donor platelets. To determine its effect on platelet refractoriness, intravenous gamma globulin (IV IgG) was administered at 400 or 800 mg/kg/d for five days, and postinfusion platelet responses were monitored. Platelet transfusion responses following intravenous gamma globulin (IV IgG) were graded as follows: Excellent, 48-hour posttransfusion count greater than 50,000/microL; good, 48-hour count greater than 20,000 but less than 50,000/microL; Fair, increased increment, 48-hour count less than 20,000; and failed, no increased increment. Six of ten patients (60%) had improved responses to selected single-donor platelets (two were excellent, three were good, and one was fair). The time to achieve a platelet transfusion count greater than 25,000/microL ranged from one to nine days of IgG therapy. One individual had sustained benefit (greater than 1 year); the remaining responses persisted for 6 to 8 weeks. These results suggest that IV IgG may be useful in the management of platelet refractoriness, especially in patients receiving single-donor platelets.     

Mixed lymphoblastic-myelomonoblastic leukemia in treated Hodgkin's disease

In a case of acute leukemia occurring 5.5 yr after diagnosis of Hodgkin's disease, a mixture of lymphoid and myelomonocytoid blasts was identified by morphological, cytochemical, and immunologic methods. The majority of blasts were characterised as lymphoid by their strong expression of nuclear terminal transferase (TdT) enzyme. In contrast, a minor blast population was identified as myelomonocytoid by the strong nonspecific esterase positivity and lack of TdT. The two distinct blast cell populations showed different sensitivity to the various chemotherapeutic protocols used.     

Autologous bone marrow transplantation with 4- hydroperoxycyclophosphamide purged marrows for acute nonlymphocytic leukemia in late remission or early relapse

Twenty-four patients with acute nonlymphocytic leukemia (ANLL) were treated with high-dose chemotherapy or chemoradiotherapy followed by infusion of autologous marrow purged with 100 micrograms/mL of 4- hydroperoxycyclophosphamide (4HC). The marrow harvests were performed when there were less than 5% blasts in the marrow. Seven patients were transplanted in second complete remission (CR), eight in third CR, one in fourth CR, and eight in early relapse. The median time to achieve 500 neutrophils/microL or 1,000 leukocytes/microL was 30 days. A platelet count of 20,000/microL and 50,000/microL was achieved at a median of 67 and 91 days, respectively. One patient failed to engraft by day 58. There were five other transplant-related deaths: sepsis (one), intracerebral hemorrhage (one), veno-occlusive disease (one), and interstitial pneumonia (two). Four of seven evaluable patients transplanted in early relapse obtained a CR lasting 112, 143, 189, and greater than 615 days. Eight of 11 evaluable patients transplanted in CR have relapsed at a median of 153 days (range, 104 to 311). The actuarial survival for all patients was 19%. There was a trend toward improved relapse-free survival for patients transplanted in remission as opposed to those transplanted in relapse (P = .11).