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H Chaplin

Publications and source records attributed to H Chaplin.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

Reproducible in vitro preparation of intermediate C3d coated red blood cells.

As a standardizing reagent and/or as a positive control for the anti-C3d reactivity of antiglobulin reagents, test red blood cells (RBC) reproducibly coated with "C3d only" (i.e. lacking other complement components and immunoglobulins) are essential. We have prepared RBC coated by intermediate amounts of C3d. Two approaches to varying the amount of C3d bound to RBC were studied: a) variation in Mg++ concentration and b) dilution of donor plasma. The amount of C3d bound to RBC was assessed both by agglutination reactions with serial dilutions of a standard anti-C3d serum and by quantitation of bound anti-C3d with 125I-labeled anti-antiglobulin serum. Marked individual donor differences were encountered in response to varying Mg++ concentration and to dilution of donor plasma; no single set of conditions could be employed to produce a desired intermediate C3d-coated RBC from all donors. Examples of variations to be expected with both manipulations are illustrated, along with studies of conditions under which the standard deviation for bound C3d on intermediate C3d-coated RBC made from 5-donor pools was less than 10%.

Animals↗
PubMedDate not supplied

Weak "false positive" direct antiglobulin test reactions with polyspecific antiglobulin reagents: lack of correlation with red-blood-cell-bound C3d.

The investigation explored whether weak positive or "rough" direct antiglobulin test (DAT) reactions observed with commercial polyspecific reagents could be correlated with the amount of C3d bound to normal donor red blood cells (RBC). Employing a radiolabeled anti-antiglobulin method, RBC-bound C3d was measured on 101 normal donor samples. In a second phase of the study, RBC-bound C3d plus igG were measured on an additional 141 donor samples. In neither phase of the study was a correlation observed between weak positive antiglobulin reactions and the amount of RBC-bound serum globulins.

Antibodies, Anti-Idiotypic↗
PubMedDate not supplied

Alloimmunization in patients with warm autoantibodies. A retrospective study employing three donor alloabsorptions to aid in antibody detection.

We examined the value of performing alloabsorptions to detect clinically significant alloantibodies in patients with warm autoantibodies who must receive crossmatch-incompatible blood. One hundred and twenty-five (125) patients were evaluated using alloabsorption with red cells (RBCs) from three donors: R1R1, R2R2, and rr, whose phenotypes other than Rh were selected to exclude 98 percent of clinically significant alloantibodies. This technic was selected rather than autoabsorption due to insufficient quantities of patient cells available and to the possible presence of transfused cells in some instances. Patients were divided into three risk categories: I--no prior pregnancy or transfusion; II--history of pregnancy and/or one to five transfusions; and III--greater than five transfusions. No significant alloantibodies were found in 32 category I patients. Of 74 category II patients, 13 (17.5%) had significant alloantibodies detectable after absorption. Six of 19 (31.5%) category III patients had alloantibodies. The majority showed Rh specificity: anti-E (13), -C (6), -c (2), -D (1). Anti-K was found in five samples. Forty-two (42%) percent of the alloantibodies were undetectable prior to the alloabsorptions. We conclude that category II and particularly category III patients are at significant risk of allosensitization and should be evaluated by an absorption procedure prior to the transfusion of crossmatch-incompatible red cells.

Adolescent↗
PubMedDate not supplied

Long-term in vivo survival of Rh(D)-negative donor red cells in a patient with anti-LW.

The present study documents immediate and long-term survival of crossmatch-incompatible Rh(D)-negative donor red cells in a patient with anti-LW. A 67-year-old group A Rh(D)-positive man was admitted for urgent coronary artery bypass surgery. The direct antiglobulin test (DAT) was weakly positive in two of five laboratories. His serum contained anti-LW (two laboratories); his red cells were LW negative (three antisera). Two siblings were LW-positive. Surgery was delayed, and 3 ml Rh(D)-negative crossmatch-incompatible red cells stored in citrate-phosphate-dextrose-adenine-one were labeled with 25 microCi of 51Cr and injected. Immediate survival was approximately 100 percent with 92 percent survival at 20 hours. Six daily blood samples showed a decreased red cell lifespan, (T 1/2 = 14 days). Because of medical complications, 4 units of Rh(D)-negative crossmatch-incompatible blood were then transfused without clinical or hemolytic reaction. The anti-IgG DAT became stronger. In vivo survival of the remaining 51Cr-RBCs became normal (T 1/2 28 days over the succeeding 20 days). Following transfusion, no change in serum antibody strength was demonstrated by double-blind titration of seven coded samples. The observations support modest reduction of lifespan for 3 ml of LW-positive red cells, but normal survival following subsequent transfusion of approximately 700 ml of LW-positive red cells.

Aged↗
PubMedDate not supplied

Clinically significant allo-anti-I in an I-negative patient with massive hemorrhage.

A 37-year-old white man who had never been transfused was admitted as an emergency patient with a ruptured spleen and a falling hematocrit (19% on admission). All crossmatches were incompatible. His serum contained anti-I, and his red cells (RBCs) were I-negative and strongly i-positive. Only 4 units of crossmatch-compatible I-negative frozen RBCs were available immediately. Because of the likelihood that more than 4 units would be required, chromium survival studies were performed using I-positive cells. Samples obtained at 15 and 30 minutes after injection revealed less than 1 percent survival of the donor RBCs. He received the 4 units of I-negative RBCs during the operation in addition to reinfusion of RBCs harvested from 1800 ml of blood aspirated from the abdominal cavity. The postoperative hematocrit remained greater than 30 percent and the bilirubin less than 1.5 mg per dl. Before recommending frozen storage of autologous RBCs, 51Cr labeled I-positive RBCs from the patient's daughter (obligate li heterozygote) were infused. Survival was 100 percent at 15 and 30 minutes, 90 percent at 3 hours, 85 percent at 26 hours; the remaining RBCs disappeared at a normal rate (T 1/2 27 days) over the succeeding 2 weeks. A repeat 51Cr-labeled RBC study with the original I-positive donor confirmed greater than 92 percent destruction in 90 minutes. The clinical significance of this allo-anti-l (apparently primarily against RBCs from homozygous I-positive donors) is in marked contrast to reported findings with auto-anti-l antibodies.

Adult↗
PubMedDate not supplied

Frozen storage of 11 units of sickle cell red cells for autologous transfusion of a single patient.

A patient with sickle cell disease and multiple alloantibodies required frozen storage of autologous red cells (RBC) to provide the RBC volume equivalent of 6 units of normal donor blood for an orthopedic surgical procedure. Eleven 600-ml donations were made at 4-week intervals, without significant change in hemoglobin concentration, hematocrit, or reticulocyte count, and with only small decreases in serum iron and ferritin concentrations. Minor modifications of a glycerolization and deglycerolization procedure described recently were used. We report in vitro recoveries of deglycerolized RBC from the 11 units following frozen storage for 27 to 391 days. Despite use of a single donor and adherence to a standardized processing protocol, considerable variation in the percent in vitro RBC recovery was observed (51-81%). In vivo survival of an aliquot following frozen storage for 27 days was identical with fresh autologous RBC (100% at 1 hr, 88% at 24 hr, one-half disappearance of 7.5 days). Autologous transfusion of RBC recovered from 7 units after storage for as long as 126 days was uneventful.

Anemia, Sickle Cell↗
PubMedDate not supplied

Anti-Jka, -C, and -E in a single patient, initially demonstrable only by the manual hexadimethrine bromide (Polybrene) test, with incompatibilities confirmed by 51Cr-labeled red cell studies.

Published reports have confirmed the superior sensitivity of the manual hexadimethrine bromide (Polybrene) test (MPT) for demonstrating many alloantibodies in vitro; however, the clinical significance of alloantibodies demonstrable exclusively by MPT has not been shown conclusively. A patient with macroglobulinemia experienced chills, fever, hemoglobinemia, and hemoglobinuria following the transfusion of 1 unit of red cells (RBCs) shown to be compatible by the low-ionic-strength antiglobulin (LIS-AG) method. Serologic investigation was negative. Intravascular hemolysis occurred with a second "compatible" unit. Serologic studies were again negative by LIS-AG and ficin-AG methods, but revealed anti-Jka by MPT. Both donors were Jk(a+b-), and 51Cr studies of the second donor's RBCs revealed a t1/2 of less than 30 minutes, with marked intravascular hemolysis. A LIS-AG-compatible Jk(a-) unit was transfused uneventfully, but with no rise in hematocrit. MPT next revealed anti-C; subsequent 51Cr studies with the Jk(a-), Cc donor's RBCs showed a 51Cr t1/2 of 100 minutes with slight intravascular lysis. Four transfusions of Jk(a-), C- blood were uneventful, but 5 days later the patient's hemoglobin declined. The following day, anti-E was demonstrable exclusively by MPT. 51Cr-labeled Jk(a-), C-, E- RBCs had normal 24-hour survival. The patient's hemoglobin rose to 11 g per dl following transfusions of Jk(a-), C-, E- RBCs, and he was discharged. In vitro studies employing the patient's purified IgM paraprotein revealed no interference with alloantibody binding or detection.

Aged↗
PubMedDate not supplied

First example of familial posttransfusion purpura in two PlA1-negative sisters.

Posttransfusion purpura (PTP) (platelet count 5000/microliter) was diagnosed in a female patient (never transfused, gravida IV, para IV) 1 week after transfusion for hysterectomy in 1978. She did not respond to pooled random-donor platelets but recovered following a single plasma exchange. Her platelets were PlA1 negative, and her plasma contained potent anti-PlA1. In 1986, her sister (never transfused, gravida III, para III) developed PTP (platelet counts 5-15,000/microliter) following surgery-associated transfusion. She did not respond to pooled random-donor platelets. Platelet-associated IgG was markedly elevated (5365) molecules/platelet; normal, less than 660); her plasma contained a potent platelet antibody with anti-PlA1 specificity. Her platelets were subsequently shown to be PlA1 negative. The platelet count did not rise above 30,000 per microliter, despite 3 days of high-dose methylprednisolone sodium succinate and 2 weeks of prednisone (80 mg/day). Later, her platelet count increased and remained normal after steroids were discontinued. The two sisters proved to be HLA-identical, and each possessed one haplotype carrying the DR3 marker, which has been implicated as a risk factor in neonatal alloimmune thrombocytopenia associated with anti-PlA1.

Antigens, Human Platelet↗
PubMedDate not supplied

Blood component use in orthotopic liver transplantation.

Blood component use during orthotopic liver transplantation (OLT) was evaluated after an initial 23-month experience with 37 consecutive transplant procedures. Blood component support of OLTs in 24 adult and 13 pediatric patients was reviewed. Adult procedures required intraoperatively a mean of 24.5 units of red cells (RBCs), 38.7 units of fresh-frozen plasma (FFP), 26.1 random-donor platelets (RDP), and 12.2 units of cryoprecipitate (Cryo); pediatric procedures required 4.8 units of RBCs, 5.8 of FFP, 3.9 of RDP, and 1.2 of Cryo. RBC salvage constituted 17 percent of the RBCs transfused intraoperatively. Intraoperative support in adult and pediatric OLT patients accounted for the majority of the total components required for the entire hospital stay. OLT blood component use constituted 1.3, 7.0, 3.6, and 8.1 percent of hospital-wide use of RBC, FFP, RDP, and Cryo, respectively, during the period of the study.

Adolescent↗
PubMedDate not supplied

Inhibition of an anti-Pr1d cold agglutinin by citrate present in commercial red cell preservative solutions.

A patient with known cold autoimmune hemolyticanemia was admitted for surgery. Routine cold agglutinin evaluations, using commercial red cells (RBCs) in modified Alsever's preservative solution, revealed a cold agglutinin titer of 4 to 16. However, using RBCs washed four times with saline, a high-titer (greater than 2000 at 4 degrees C) cold autoagglutinin was demonstrated. The cold agglutinin was shown to be an IgM kappa paraprotein with anti-Pr1d specificity. The addition of Alsever's solution to washed RBCs inhibited the cold agglutinin. Each major component of Alsever's solution (neomycin, chloramphenicol, inosine, dextrose, and citrate) was tested individually; only citrate inhibited the patient's cold agglutinin. Various compounds structurally related to citrate were tested and found to cause various degrees of inhibition. The strongest inhibition correlated with the presence of either three carboxyl groups on molecules devoid of double-bonded carbon atoms or two carboxyl groups in cis configuration. A panel of 54 cold agglutinins, including 7 with anti-Pr specificity, was analyzed. None was significantly inhibited by Alsever's solution, although one with anti-Pr2 specificity was weakly inhibited. In summary, these studies describe an anti-Pr1d cold autoagglutinin that was inhibited by citrate in RBC preservative solutions. The failure to detect such a cold agglutinin can result from not washing RBCs free of citrate before testing.

Aged↗
PubMedDate not supplied

Life-threatening, antiglobulin test-negative, acute autoimmune hemolytic anemia due to a non-complement-activating IgG1 kappa cold antibody with Pra specificity.

A 21-year-old man with fulminant cold autoantibody hemolytic anemia (CAHA) was hospitalized with hemoglobinemia, hemoglobinuria, hemoglobin concentration of 3.3 gm per dL, a negative direct antiglobulin test (DAT) with polyspecific and anti-C3d reagents, a negative Donath-Landsteiner test, and a cold agglutinin titer of 80. He failed to respond to corticosteroids, multiple plasma exchanges, and cyclophosphamide; he required 54 transfusions in 10 days to maintain a hemoglobin concentration of 6.0 to 10.0 g per dL. He improved dramatically after a splenectomy was performed. The wide-thermal-amplitude cold agglutinin proved to be an IgG1 kappa antibody with Pra specificity. The patient's serum exhibited normal complement activation. When the DAT was carried out at 0 to 4 degrees C, the result was strongly positive for IgG; the indirect antiglobulin test at 0 to 4 degrees C was positive with the patient's serum diluted 1 in 640. Within 6 months, he was in complete remission and receiving no therapy. As compared with eight patients with CAHA that was exclusively IgG-mediated, this patient is remarkable for his requirement for many transfusions and for DATs that were consistently negative for C3d.

Adult↗
PubMedDate not supplied

A latex particle assay for platelet-associated IgG.

A modified, sensitive, solid-phase assay for platelet-associated IgG is reported. Direct comparisons were made between a 125I monoclonal radioimmunoassay (RIA) and the polyclonal antibody latex particle assay. In 209 simultaneous comparisons with the RIA, the sensitivity of the latex test was 91 percent, specificity was 100 percent, and overall efficiency was 97 percent. Commencing with platelet-rich plasma, the direct latex particle test for platelet-bound IgG requires 45 minutes; 90 minutes are required to crossmatch one patient with 12 donors. The advantages of the latex assay are absence of radioactivity, stability of reagents, economy, speed, specificity, and sensitivity.

Antibodies, Monoclonal↗
PubMedDate not supplied

Severe immune-mediated hemolytic anemia secondary to treatment with cefotetan.

Severe acute hemolytic anemia developed in a woman following treatment with multiple antibiotics for possible postpartum uterine infection. On admission, the hemoglobin was 5 g per dL (50 g/L), the reticulocytes were 35 percent (0.350), the direct antiglobulin test was strongly positive for IgG and C3d (mixed fields), and the indirect antiglobulin test was negative. Serologic studies revealed antibody to cefotetan that reacted by both the immune complex and the drug adsorption mechanisms. Before the diagnosis of cefotetan-related immune hemolysis was made, all medications had been discontinued, and the patient received 4 units of red cells and a short course of adrenocorticosteroids. Recovery was prompt and complete.

Adult↗