Antiphospholipid syndrome: a series of surgical emergencies and the current evidence for its management.

It is generally accepted that antiphospholipid syndrome remains a major medical problem characterised by hypercoagulability, arterial and venous thrombosis and thrombocytopenia. It is unclear how best to treat these patients should they require emergency surgery. If a lupus anticoagulant is present, hypercoagulability may occur de novo but surgical interventions along with sepsis are two important predisposing factors. We describe three patients with primary antiphospholipid syndrome and discuss the implications for surgery.

Clearance of red cells by monoclonal IgG3 anti-D in vivo is affected by the VF polymorphism of Fcgamma RIIIa (CD16).

Human red cells (RBC) coated with IgG anti-D are cleared from the circulation to the spleen by macrophages which express IgG receptors (Fcgamma R). Polymorphisms of Fcgamma RIIa and Fcgamma RIIIa affect IgG binding in vitro, and may alter the efficiency of clearance of immune complexes in vivo. In a RBC clearance study, 22 Rh D-negative subjects were given 100-400 micro g human monoclonal or polyclonal IgG anti-D i.m. followed 48 h later by 51Cr-labelled D+ RBC. The half lives of the infused D+ RBC were determined, together with the coating levels of anti-D on the D+ RBC. Fcgamma RIIA and FcgammaRIIIA genotyping was performed. Large ranges of phagocytosis and extracellular lysis of RBC in vitro, and of half lives of RBC in vivo, were observed. Clearance of RBC coated with monoclonal IgG3 anti-D (BRAD-3) was more rapid in five subjects homozygous for Fcgamma RIIIa-F/F158 than in three subjects expressing the Fcgamma RIIIa-V158 allele (P = 0.024). This effect was not observed, however, for those individuals given polyclonal anti-D. There was also no significant difference in the efficiency of RBC destruction in vitro or of RBC clearance in vivo between the subjects analysed for individual genotypes or alleles or combinations of alleles. In conclusion, the presence of the Fcgamma RIIIa-V158 allele compromised the efficiency of removal of RBC coated with IgG3 anti-D.

Haemolytic disease of the fetus and newborn due to anti-Fy(a) and the potential clinical value of Duffy genotyping in pregnancies at risk.

Haemolytic disease of the newborn (HDN) caused by anti-Fy(a) is uncommon and usually mild. Current guidelines recommend that pregnant women with anti-Fy(a) are monitored less rigorously than those with anti-D, -c or -K. However, in a review of our recent experience of 68 pregnancies where anti-Fy(a) was detected, three were identified where the fetus was severely anaemic; in two cases the fetus received intrauterine transfusions. Our data suggest that pregnancies in which anti-Fy(a) is detected at significant titres (> 64) should be closely monitored in a similar way to pregnancies where other 'significant' antibodies are present. Moreover, in the presence of high or rising antibody titres, if the father is heterozygous and functional assays suggest the antibody is active, then fetal genotyping should be offered to help plan the future management of that pregnancy.

Prestorage white cell reduction in saline-adenine-glucose-mannitol red cells by use of an integral filter: evaluation of storage values and invivo recovery.

BACKGROUND: Prestorage white cell (WBC) reduction in blood components may decrease the incidence of adverse reactions and improve component quality. A bottom-and-top system with an integral third-generation WBC-reduction filter has been studied. STUDY DESIGN AND METHODS: Whole blood was collected from 30 healthy donors: from 20 by using a blood container system with an integral filter and from 10 controls by using a standard blood container system. Ten test units were buffy coat-depleted, stored for 72 hours at 4 degrees C, and then filtered, while an additional 10 test units were buffy coat-depleted and filtered at room temperature within 8 hours of collection. All units were stored at 4 degrees C for 42 days and sampled weekly. RESULTS: The mean WBC content of the 72-hour, 4 degrees C units was 0.33 x 10(6), that of the room-temperature units was 2.6 x 10(6), and that of the buffy coat-depleted controls was 460 x 10(6) (p < 0.0005). No significant differences were found among lactate, glucose, sodium, potassium, and plasma hemoglobin levels in the three groups. ATP and 2,3 DPG levels were significantly better preserved in control units than in 72-hour, 4 degrees C units (p = 0.016 and p = 0.032, respectively), but not better than in the room-temperature units. Significant differences were observed between pH values in filtered units and both groups of test units (p = 0.016). In biologic terms however, these differences were small. Red cells from an additional eight healthy volunteer donors were processed by an 8-hour room-temperature method and stored for 35 days. Studies in vivo 24-hour recovery of autologous red cells were performed by transfusing a radiolabeled (51Cr plus 131I-albumin) aliquot after 35 days' storage. Good recovery (mean > 80%) was found by both the single- and double-isotope-label methods. Recovery was significantly greater when calculated by the single-isotope method (p = 0.02). CONCLUSION: The combination of buffy coat removal and filtration in the blood container system with an integral filter achieved effective WBC reduction (> or = 3 log10 reduction from whole blood) without biologically significant detriment to in vitro or in vivo storage values.

Human Rh D monoclonal antibodies (BRAD-3 and BRAD-5) cause accelerated clearance of Rh D+ red blood cells and suppression of Rh D immunization in Rh D- volunteers.

The use of prophylactic anti-D to prevent Rh D immunization in Rh D- women and subsequent hemolytic disease in Rh D+ infants is widespread, but has led to shortages of the anti-D Ig. With the aim of substituting monoclonal anti-D for Rh D prophylaxis, we have compared the abilities of monoclonal and polyclonal anti-D to clear Rh D+ red blood cells (RBCs) infused into Rh D- male volunteers and to suppress Rh D immunization. Two human monoclonal antibodies (MoAbs), BRAD-3 (IgG3) and BRAD-5 (IgG1), produced from stable Epstein-Barr virus-transformed B-lymphoblastoid cell lines, were selected because of their proven in vitro activity in promoting RBC lysis in antibody-dependent cell-mediated cytotoxicity assays. RBC clearance was assessed by intravenous injection of 3 mL of 51chromium-labeled D+ RBCs into 27 volunteers 48 hours after intramuscular injection of monoclonal or polyclonal anti-D. Further 3-mL injections of unlabeled D+ cells were administered at 6 and 9 months to induce immunization. Blood samples were taken throughout the 12-month period of study for the serologic detection of anti-D. The mean half-life (t50%) of RBCs in 7 recipients of 300 micrograms BRAD-5 (5.9 hours) was similar to that in 8 recipients of 500 IU polyclonal anti-D (5.0 hours), whereas D+ cells were cleared more slowly in some of the 8 subjects injected with 300 micrograms BRAD-3 (mean t50% 12.7 hours) and in 1 individual administered 100 micrograms BRAD-3 (t50% 41.0 hours). The rate of RBC clearance in both groups administered 300 micrograms monoclonal anti-D correlated with the amount of antibody bound per cell, determined by flow cytometry. There was no evidence of primary immunization having occurred in any subject after 6 months of follow-up. Five of 24 subjects produced anti-D after one or two further injections of RBCs, confirming that they were responders who had been protected by the monoclonal or polyclonal anti-D administered initially. Four of these responders were recipients of monoclonal anti-D (3 BRAD-3, 1 BRAD-5). One individual who received BRAD-5 produced accelerated clearance of D+ RBCs at the third unprotected RBC challenge but did not seroconvert. This study shows that the human MoAbs BRAD-3 and BRAD-5 can prevent Rh D immunization, and indicates that they may be suitable replacements for the polyclonal anti-D presently used in prophylaxis of Rh D hemolytic disease of the newborn.(ABSTRACT TRUNCATED AT 400 WORDS)

Hepatitis C (HCV)-positive blood donors in south-west England: a case control study.

The aim of this study was to compare the socio-demographic characteristics and risk factors in anti-HCV positive blood donors with those of matched controls. The participants were 50 hepatitis C antibody (HCV) positive blood donors and 50 matched blood donors with no evidence of HCV infection, who gave blood to the South Western Transfusion Centre between November 1991 and July 1992. A confidential structured interview was conducted to collect socio-demographic data and to elicit information on risk factors for HCV. Measurements were made of the prevalence of risk factors and socio-demographic characteristics in cases and controls. The main results were that 45 of the 50 cases could have been exposed to HCV by previous intravenous drug abuse (IVDA), blood transfusion or medical employment. Cases were significantly more likely to have a history of IVDA, tattooing or of medical employment than matched controls. Cases with no history of IVDA were significantly more likely to have had a blood transfusion. The key conclusions to emerge are that current policies are ineffective at excluding those with a history of IVDA from the donor pool. Consideration should be given to the introduction of a policy of direct confidential questioning about risk factors for all donors, or, at a minimum, the use of a questionnaire.

Inaccurate haemoglobin estimation in Waldenström's macroglobulinaemia: unusual reaction with monomeric IgM paraprotein.

Automated blood counts from a patient with Waldenström's macroglobulinaemia repeatedly failed critical limit standards set for mean cell haemoglobin concentration and mean cell haemoglobin. Haemoglobin estimation was higher than that suggested by clinical examination, symptoms, and the spun haematocrit. This was found to be due to an interaction between the Coulter lysing agent and monomeric IgM paraprotein in the patient's plasma, creating a precipitate which was optically dense at 525 nm.

Acquired factor XI inhibitor in chronic lymphocytic leukaemia.

A 71 year old man with chronic lymphocytic leukaemia (CLL) experienced excessive bleeding following transurethral resection of the prostate. Investigations showed a prolonged kaolin cephalin clotting time (KCCT) with low concentrations of factor XI. The prolonged KCCT was largely corrected by mixing with normal plasma but this correction was lost on incubation, confirming the presence of an inhibitor. He was treated with pulsed methylprednisolone and chlorambucil which resulted in the resolution of the bleeding problem and the loss of detectable circulating inhibitor.