Hypergammaglobulinemia can be associated with a positive direct antiglobulin test, a nonreactive eluate, and no evidence of hemolysis

To determine the cause of a positive direct antiglobulin test (DAT), blood banks routinely perform serologic tests on eluates prepared from DAT-positive red cells. Negative eluates traditionally have been suspected to be associated with drug reactions. This report confirms that the most frequent cause of a positive DAT and a nonreactive eluate is hypergammaglobulinemia. The results of 74 patient samples with positive DATs were analyzed retrospectively. Eluates prepared from the red cells of 54 patients (72.9%) reacted; eluates from 20 patients (27.1%) did not react. This latter group had identical serologic and clinical findings, suggesting that they made up a homogeneous group. In particular, the patients had a positive DAT, a negative indirect antiglobulin test, and a negative eluate; an increased serum concentration of IgG; and no evidence of hemolysis. In a subsequent study, DATs were performed prospectively on red cells from 44 consecutive patients with elevated serum IgG levels. The serum IgG concentration was highest in the three patients whose red cells had a positive DAT. The DAT also became positive in two patients treated with high-dose intravenous gammaglobulin (IV IgG). These studies indicate that a negative eluate from red cells with a positive DAT, a common serologic finding, is often caused by hypergammaglobulinemia. The authors postulate that IgG binds nonspecifically to the red cells because of the hypergammaglobulinemia.     

Incidence of antibody formation and positive direct antiglobulin tests in a multitransfused hemodialysis population

In order to determine the degree and significance of red cell antibody production by dialysis patients, two groups of patients were studied retrospectively. One hundred and five randomly selected dialysis patients (Group I) receiving a total of 1074 units of blood were reviewed, as were 38 patients who were given frozen-thawed red cells because of intractable nonhemolytic febrile reactions following transfusions of red cells stored conventionally (Group II). Eleven patients in Group I produced alloantibodies: nine after the start of dialysis. Of these, two patients had antibodies that were judged clinically insignificant. Eleven of 38 patients in Group II had red cell alloantibodies at the time of study, four of which were judged clinically significant. The direct antiglobulin test (DAT) was positive in 14 patients in Group I and eight patients in Group II for an overall percentage of 15. The cause of the positive DAT was determined in eluates for 26 percent of the cases studied. Clinically significant antibodies were produced by 6.7 percent of randomly selected dialysis patients (Group I). This incidence is lower than other chronically transfused patient populations reported, but higher than that reported in transfused patients at large. The incidence of positive DATs was higher than in some populations reported but not others.     

The efficacy of performing red cell elution studies in the pretransfusion testing of patients with positive direct antiglobulin tests

In order to evaluate the efficacy of performing red cell elutions in pretransfusion testing, the serologic records of 638 patients with positive direct antiglobulin tests (DAT) were reviewed. These patients were identified by routine antibody screening procedures that included an autologous control. DAT results on the red cells of these patients showed 279 with IgG and C3d sensitization, 319 with IgG alone, and 40 with C3d sensitization alone. Of 638 patients' red cell eluates, 401 demonstrated no reactivity, 154 demonstrated panagglutination, and 60 demonstrated passively acquired anti-A,B. Only 23 of 638 patients had alloantibody sensitization of their red cells. Of the 23, 19 had serum antibody corresponding to the specificity of antibody detected in the eluate. Thus, only four of 638 (0.6%) eluates gave results unavailable by serum testing alone. This study indicates that routine eluate investigation provides little useful information in assuring compatibility. Serum antibody testing and careful review of the clinical and transfusion history constitute appropriate pretransfusion testing in patients with positive direct antiglobulin tests. Eluate testing should be restricted to cases in which immune hemolysis is suspected clinically.     

The evaluation of a positive direct antiglobulin test in pretransfusion testing

The results of serologic studies on 879 blood samples with a positive direct antiglobulin test (DAT) are presented. All blood samples were from patients who were either anemic, for reasons other than blood loss, recently transfused, or had serum antibodies detected during routine pretransfusion tests. Blood samples from only 81 of the patients included in this study had serologically reactive eluates (64 autoantibodies, three antibodies to penicillin and cephalothin treated red blood cells, three passively acquired anti-A antibodies, and 11 transfusion-induced alloantibodies). The eluted antibodies were also detected in the serum by routine pretransfusion tests in 13 of the patients whose red blood cells eluted autoantibodies, and in five of the patients whose red blood cells eluted transfusion-induced alloantibodies. All but one of the 11 transfusion-induced alloantibodies were detected within 14 days posttransfusion. Based on these findings, a cost-effective and safe approach to the management of blood samples with a positive DAT would be to restrict the preparation and testing of eluates to those samples from recently transfused patients. It is the contention of the authors that the incorporation of the DAT in pretransfusion testing should primarily serve to detect alloantibody formation before such antibodies are evident in the serum, and should not be used to screen patients for unsuspected autoimmune hemolytic anemia. Furthermore, the authors question the necessity for blood banks to routinely perform an autocontrol on all blood samples from prospective transfusion recipients.     

The role of the elution in antibody investigations

BACKGROUND: The direct antiglobulin test (DAT) commonly detects immunoglobulin G (IgG) molecules or complement fragments on the red blood cell (RBC) surface. If IgG antibodies are present then elution procedures can be performed to identify the specificity of these antibodies. Our reference laboratory performs elutions on the RBCs of those patients who have received cellular blood products in the past 30 days and have either a newly identified positive DAT with anti-IgG or the agglutination strength is increased over a previous DAT and if ordered by a clinician regardless of transfusion history. This study questioned how frequently elutions contributed novel serologic information under our reference laboratory's current policy or whether elutions should be performed in more selective serologic conditions.
STUDY DESIGN AND METHODS: Recipients whose RBCs underwent eluate testing were identified from the blood bank's database and information about the antecedent DAT and antibody detection test and eluate was recorded.
RESULTS: In total 648 eluates were evaluated and 82 of 648 (12.7%) revealed a novel antibody not present in the serum (an informative eluate). In 2 of 82 informative eluates non–anti-A/B alloantibodies that were not present in the serum were detected: one example each of anti-D and anti-E. Both were associated with a microscopically positive antecedent DAT. The rate of an informative eluate was higher when the antibody detection test was negative.
CONCLUSION: The strength of the DAT does not indicate the likelihood of an informative eluate. Performing an eluate when the antibody detection test is positive has limited value.     

Is it necessary to add the eluate testing to the direct antiglobulin test to improve the detection of maternal erythrocyte alloantibodies?

BACKGROUNDThe screening of umbilical cord blood samples by the Direct Antiglobulin Test (DAT) is the reference tool for the identification of maternal erythrocyte alloantibodies present in erythrocytes; however, its diagnostic usefulness is controversial.OBJECTIVETo evaluate the diagnostic validity, safety, and efficiency of the eluate testing (detection of antibody in erythrocyte eluates by the Indirect Antiglobulin Test/IAT) in cord blood samples for detection of maternal erythrocyte alloantibodies in comparison with the DAT.MATERIALS AND METHODSEvaluation study of diagnostic tests. DAT and eluate testing were performed in 306 cord blood samples from neonates born to mothers admitted at Clínica Somer in Rionegro, Colombia; then, antibodies present in the eluates were identified with erythrocyte panels. Percentage of positive results by DAT and IAT were compared with the Pearson's chi-square test and the agreement between both assays with the Cohen's kappa coefficient. The diagnostic sensitivity, specificity, safety, and efficiency of the eluate testing were calculated, taking into account the use of DAT as an imperfect reference test.RESULTSThe DAT detected alloantibodies in 6.21% of samples and the eluate testing in 14.1 %; the strength of agreement between both tests was moderate (k = 0.56) due to 25 discrepancies. The eluate testing showed sensitivity and specificity of 98.83 % and 92.31 % respectively, and a negative predictive value of 99.9 %. The diagnostic efficiency was sufficient for detection of maternal erythrocyte alloantibodies. The antibodies identified in the erythrocyte eluates were anti-A or anti-B (79.5 %), anti-D (136%), anti-C (2,3%), and anti-Fya (2,3%).CONCLUSIONThe eluate testing in cord blood samples is a valid, safe, and efficient test for the diagnosis of maternal erythrocyte alloantibodies.     

Long-term production of pre-existing alloantibodies to E and c after allogenic BMT in a patient with aplastic anemia resulting in delayed hemolytic anemia

BACKGROUND: Delayed hemolysis mediated by long-term production of pre-existing recipient-derived antibodies directed against donor RBC antigens after allogenic BMT is an unusual complication of hematopoietic transplantation. CASE REPORT: A 26-year-old man with aplastic anemia had pre-existing alloantibodies to E and c. He received BMT from a donor, whose Rh phenotype was E+, c+. From about 1 month after the transplant, he showed mild hemolysis due to the antibodies. RESULTS: The patient was typed as group B, CCDee and had anti-E and c alloantibodies before BMT. The donor was typed as group O, ccDEE. Although MNCs from the donor marrow were infused into the patient, DAT became positive on Day 21, and the patient-origin antibodies remained detectable by both DAT and IAT even 20 months after BMT. However, immunomagnetically isolated peripheral circulating B cells were 100 percent donor origin. The patient received prednisolone from Day 221, and thereafter, the signs of hemolysis disappeared. CONCLUSION: It is likely that the long-term production of alloantibodies is due to the existence of long-lived recipient plasma cells, which survive the conditioning regimen. This case suggests that patients with pre- existing alloantibodies that do not belong to the ABO system should be carefully followed up after BMT.     

Discrepancies in reverse ABO typing due to prozone

Three group O sera manifesting prozone in reverse ABO tests are reported. All were implicated in erroneous blood typing results. One sample failed to react with A1 red cells (RBCs) in immediate-spin (IS) tests, had anti-A and -B titers of 8192 and 2048, respectively, by indirect antiglobulin technique (IAT), and was from a diabetic patient; the parenteral administration of A substance present in porcine insulin is a possible cause of hyperimmunity in this case. The second sample was from the recipient of a single unit of group B fresh-frozen plasma; the serum anti-A and -B titers were 10,240 by IAT, but only weak reactions with A1 and B RBCs were noted in routine IS reverse typing tests; the hyperimmunity in the patient concerned was likely due to crossreacting anti-A, B stimulated by B-active glycoproteins and/or glycolipids in the transfused plasma. The third serum also had anti-A and anti-B IAT titers of 10,240 but did not react with A1 and B RBCs by IS; the hyperimmunity in this case may be related to sepsis from intestinal flora carrying A- and/or B-like antigens. These antibodies lysed A1 and/or B RBCs in tests incubated at room temperature (RT) and strongly agglutinated those RBCs by IS when diluted 10-fold with saline. The absence of the prozone phenomenon in tests with RBCs suspended in diluents containing EDTA is consistent with the previously published mechanism for anti-A prozone: namely, the steric hindrance of agglutination by the C1 component of human complement.(ABSTRACT TRUNCATED AT 250 WORDS)     

The importance of ABH antigens in platelet crossmatching

In the present study, the frequency with which ABH incompatibility could be detected in platelet crossmatches was determined. The effect of chloroquine elution on ABH antigens was also evaluated, and a technique was developed to remove IgG anti-A from group O plasma using a chemically synthesized human blood group A trisaccharide antigen covalently linked to crystalline silica (Synsorb-A). Group O plasmas were found to be incompatible with 52 percent of group A platelets and 17 percent of group B platelets (p less than 0.05). In contrast, anti-A from group B plasmas rarely produced a positive crossmatch, and no anti-B that reacted with platelets could be demonstrated in group A plasmas. IgG anti-A reactions with group A platelets were eliminated in 100 percent of the group O plasmas tested after treatment with the synthetic solid-phase immunoadsorption technique. Synsorb-A may be a useful adjunct to platelet serologic testing when group O sera need to be tested against A platelets. Group A platelets bound less anti-A after exposure to chloroquine, but only 17 percent of platelets became negative when crossmatched with group O plasma. It was concluded that increased IgG binding occurs in a majority of platelet crossmatches using a k-ELISA technique when group O recipients are tested against group A donors. These results offer a potential explanation for conflicting results in studies of transfusion results with ABH-incompatible platelets. Transfusions of group B platelets to incompatible recipients may be more likely to yield satisfactory increments than incompatible transfusions of group A platelets, but this remains to be proven. There appear to be significant differences between red cells and platelets in regard to serologic reactivity in the ABH system.     

Anti-A and/or anti-B is not detectable in some patients who underwent ABO-incompatible bone marrow transplantation

BACKGROUND: Recently, anti-A and/or anti-B produced by B cells from donor marrow could not be detected for more than 20 weeks in some patients who had undergone ABO-incompatible bone marrow transplantation (BMT). STUDY DESIGN AND METHODS: Twelve to 72 weeks after 11 patients underwent ABO-incompatible BMT, titers of anti-A and anti-B were assayed, A and B antigens were identified by routine methods and flow cytometry, direct and indirect antiglobulin tests were performed, and the red cell antibody was eluted. RESULTS: In some patients who underwent ABO-incompatible BMT, anti-A and/or anti-B produced by the B cells from the donor marrow could not be detected after BMT when red cells taken from the patients before BMT carried the corresponding antigen–that is, when hematopoiesis had already changed the cells to the donor's type according to ABO blood typing. Furthermore, some blood samples from those patients gave positive results in direct antiglobulin tests. Blood typing of patients after BMT showed mixed- field agglutination. In one patient, the half-life of red cells assayed with 51Cr was 22.4 days (30.0 +/− 4.0 days for normal controls). CONCLUSION: Although many hypotheses could be considered to explain the present data, the possibility is proposed that anti-A and/or anti-B in the sera must have been consumed in some patients who underwent ABO- incompatible BMT. This may lead to problems such as difficulty of ABO typing, positive direct antiglobulin tests, and a relatively short life span of red cells.     

Direct antiglobulin tests in narcotic addicted patients

Direct Antiglobulin Tests (DAT) as well as a number of immunological parameters (immunoglobulin levels, latex fixation, VDRL) were studied in 168 narcotic-addicted patients. Of these, 94 were untreated narcotic addicts (Group I), 61 were methadone maintained patients (Group II), and 13 had completed successful detoxification with methadone and were drug-free (Group III). Weakly positive DAT were detected in 2.1 per cent of individuals in Group I, 18 per cent in Group II, and 15 per cent in Group III. The reactions were usually transient. A number of other immunological aberrations were also present in individuals of all three groups, but there was no correlation between these parameters and the positive direct antiglobulin reactions.     

抗人球蛋白试验阳性与恶性血液病的关联性及输血治疗的探讨

目的：恶性血液病常合并自身免疫性溶血性贫血,对血液科抗人球蛋白试验阳性患者进行统计分析,探讨疾病的关联性和输血治疗的方向。方法：采用微柱凝集法对患者血样做抗人球蛋白试验,包括直接抗人球蛋白试验（DAT）和间接抗人球蛋白试验（IAT）。结果：263例抗人球蛋白试验中阳性为69例,直抗（DAT）和间抗（IAT）均阳性有4例,单纯DAT阳性65例。其中原发性阳性率占7．2％,继发性占17．5％。结论：恶性血液病会继发自身免疫性溶血,并且对溶血性贫血的患者先申请做直接和间接抗人球蛋白试验,清楚发生溶血的原因后再申请用何种成分红细胞输血治疗,以达到理想的输血效果。     

Effects of high-dose of intravenous immunoglobulin and antibiotics on survival for severe sepsis undergoing surgery

The objective of this study was to assess the impact on outcome of adjuvant therapy (high-dose of immunoglobulin [Ig] M-enriched intravenous Ig, IVIG) in intensive care unit (ICU) patients who underwent surgery by abdominal sepsis. This was a prospective, randomized, double-blind, controlled study set in the medical/surgical ICUs of seven teaching hospitals. Patients with severe sepsis and septic shock of intra-abdominal origin admitted to the ICU within 24 h after the onset of symptoms were included in the study. Polyvalent IgM-enriched Ig (Pentaglobin; IVIG group) at a dosage of 7 mL/kg/day for 5 days or an equal amount of 5% human albumin (control group) was randomized. Fifty-six patients were enrolled. The overall mortality rate was 37.5.%. Twenty patients had shock and 36 had severe sepsis (the mortality rate was 55.0% and 25.0%, respectively). In the intent-to-treat analysis, the mortality rate was reduced from 48.1% in patients treated with antibiotic (ATB) plus albumin to 27.5% (P = 0.06) for patients with ATB plus IVIG. The organ failure score (1.0 +/- 0.6 vs. 1.2 +/- 0.9), organ dysfunction score (1.7 +/- 1.1 vs. 1.8 +/- 1.0), and reoperation rate (17.2% vs. 29.6%) were not different between IVIG and control groups, respectively. Eight patients (14.3%) received inappropriate ATB initial therapy (IAT), and seven died (87.5%). IAT was the only variable independently associated with death (odds ratio, 19.4) in a logistic regression model. We conclude that IVIG administration, when used in combination with adequate antibiotics, improved the survival of surgical ICU patients with intra-abdominal sepsis. The initial choice of antibiotic has a dramatic impact on outcome.     

The evaluation of a positive direct antiglobulin test (autocontrol) in pretransfusion testing revisited

Direct antiglobulin tests (DATs) using anti-IgG were performed on 65,049 blood samples from prospective transfusion recipients; 3570 tests (5.49%) were positive. Using criteria published previously (primarily excluding patients not transfused within the preceding 14 days), 778 samples from other than neonatal patients were selected for further evaluation. Eluates that did not react were obtained on 518 (66.6%) of these samples. Warm-reactive autoantibodies were apparent in 192 eluates, while 16 contained drug-related antibodies, anti-A or anti-B from prior transfusion with ABO mismatched blood components, or anti-D passively acquired from immune serum globulin. Fifty-two eluates contained alloantibodies; however, in only six of these cases did the corresponding serum lack unexpected alloantibodies, as determined by routine pretransfusion studies. Three additional weakly reactive clinically significant alloantibodies were detected solely through additional serum tests performed on DAT-positive samples. On the basis of these findings, the DAT had a low predictive value when used to detect the early manifestations of an immune response to recently transfused red cells. Elimination of the autocontrol from routine pretransfusion testing, therefore, carries minimal risk to patients yet will undoubtedly contribute to the containment of health care costs. Moreover, the risk is lower than that associated with the elimination of the antiglobulin crossmatch.     

Prevalence of hepatitis G virus RNA in French blood donors and recipients

BACKGROUND: Recently, cases of chronic hepatitis were linked to the presence of genomic sequences of a newly described RNA virus termed hepatitis G virus (HGV) and belonging to the Flaviviridae family. STUDY DESIGN AND METHODS: The presence of HGV RNA was searched for by polymerase chain reaction in a population of blood donors and in patients who had received multiple blood component transfusions and/or intravenous immunoglobulin (IVIG) infusions. RESULTS: Twenty-one (4.2%) of 500 donors were positive for HGV RNA as were 21 (10.7%) of 196 nonimmunosuppressed patients who had received multiple transfusions of packed red cells, 4 (8.7%) of 46 common variable immune deficiency (CVID) patients who had received only IVIG, and 22 (24.7%) of 89 bone marrow transplant (BMT) patients who had received IVIG and cellular components. The proportion of HGV-positive individuals was significantly higher in the immunosuppressed recipients (CVID and BMT patients) than in the nonimmunosuppressed patients who were multiply transfused with packed red cells (p < 0.03). The proportion of HGV- positive individuals was significantly higher in the BMT patients who had received IVIG and cellular components than in the CVID patients who had received IVIG only (p < 0.03). Eight (17.0%) of the 47 HGV-positive recipients and 48 (16.9%) of the 284 HGV-negative recipients had a serum alanine aminotransferase level higher than the upper limit of normal (nonsignificant difference). The medical history of HGV-positive donors failed to reveal a particular at-risk event. The large majority of HGV-infected patients had a normal serum alanine aminotransferase level, and the proportion of patients with elevated alanine aminotransferase was the same in HGV-positive and in HGV-negative recipients. CONCLUSION: The pathological significance of HGV infection remains unelucidated, and the classification of HGV as a new hepatitis virus was perhaps premature.     

Serologic findings in autoimmune hemolytic anemia associated with immunoglobulin M warm autoantibodies

BACKGROUND: Autoimmune hemolytic anemia (AIHA) associated with immunoglobulin M (IgM) warm autoantibodies is unusual but often severe, with more fatalities than other types of AIHA. Diagnosing this type of AIHA can be difficult because routine serologic data are not always informative.
STUDY DESIGN AND METHODS: Forty-nine cases of IgM warm AIHA in 25 years were studied by serologic methods.
RESULTS: Routine direct antiglobulin tests (DATs) detected red blood cell (RBC)-bound C3 in 90 percent of cases (65% had C3 but no immunoglobulin G [IgG] on their RBCs) and IgG in 24 percent. IgM was detected on 29 of 47 (62%) patients' RBCs; RBC-bound IgM was detected in 14 of 47 cases by a tube DAT method and in an additional 15 of 21 (71%) cases using fluorescein isothiocyanate anti-IgM and flow cytometry. Eighty-one percent of eluates from patients' RBCs reacted. Warm autoagglutinins were present in 94 percent of serum samples; untreated and enzyme-treated RBCs were hemolyzed at 37°C by 13 and 65 percent of serum samples, respectively. Most agglutinins were optimally reactive at 30 to 37°C. Patients' RBCs were spontaneously agglutinated in 78 percent of cases; washing with 37°C saline or treating RBCs with dithiothreitol resolved this problem. Clear specificity of autoantibody was defined in 35 percent of serum samples.
CONCLUSION: IgM warm AIHA can be confused with cold agglutinin syndrome and "mixed/combined"-type AIHA; a serologic workup by a specialist reference laboratory can help with the diagnosis.     

False-positive results with chemically modified anti-D do not indicate a need to use a separate, immunologically inert Rh control reagent

Thirteen of 1450 (0.9%) Rh-negative samples submitted for pretransfusion or prenatal testing gave weak false-positive reactions in immediate-spin (IS) tests with chemically modified anti-D (CM-D). Only seven reacted in control tests with anti-A and/or -B. The other six samples could have been considered Rh positive; however, such a conclusion is inappropriate, since stronger (greater than or equal to 3+) reactions are expected in IS tests with CM-D and the vast majority of true Rh-positive blood samples. Moreover, three of the six false-positive CM-D reactions associated with negative control tests were from patients previously found to be Rh negative. The other three samples gave 1+ to 2+ reactions with CM-D and did not react with anti-A and/or -B; these erroneous CM-D reactions were recognized by confirmatory tests with high-protein anti-D and Rh control reagents that were performed because previous typing results were not on file. Such confirmation, as well as careful grading and proper interpretation of serologic reactions, serves to prevent erroneous Rh typing without the use of a separate, immunologically inert Rh control reagent.     

凝胶微柱法与试管法检测放散液中抗体的比较

目的比较凝胶微柱法和试管法检测红细胞释放液抗体的能力。方法将30例外周血和41例脐血红细胞用两种方法测定直接抗人球蛋白试验(DAT)并进行酸放散,将放散液与三种谱细胞、A1、B细胞反应检测抗体的特异性。71例中12例作为阴性对照样本(DAT均为阴性),其中6例为健康献血者外周血,6例为不发生新生儿溶血病(Heamolytic disease of thenewborn,HDN)的婴儿脐血样本。结果24例外周血放散液中有10例两种方法均阳性,12例均为阴性,2例自身免疫性溶血性贫血(AIHA)患者样本凝胶微柱法阳性而试管凝集法阴性,6例健康捐献者的样本DAT试验阴性且两种方法检测放散液均为阴性;41例脐血样本中33例放散液两种方法均反应,2例放散液在试管法中与A1和B细胞反应而同样的放散液做凝胶微柱法时一个和A1细胞反应,另一个只与B细胞反应。结论两种方法检测放散液结果基本是一致的,检测AIHA患者红细胞释放液抗体时用微柱法比较好,检测脐血细胞释放的同种血凝素时试管凝集法更好—些。     

RBC autoantibodies in autoimmune lymphoproliferative syndrome

BACKGROUND: Patients with autoimmune lymphoproliferative syndrome (ALPS) have an autosomal dominant genetic defect that affects lymphocyte apoptosis and is associated with chronic nonmalignant lymphadenopathy, splenomegaly, and autoimmunity, particularly affecting RBCs, WBCs, and platelets. STUDY DESIGN AND METHODS: DATs were performed on 34 consecutive patients with ALPS and 37 of their clinically unaffected relatives. The effects of age, sex, race, and immunoglobulin levels on the incidence of autoantibodies and clinical hemolysis were assessed. RESULTS: The DAT was positive in 21 (62%) of ALPS patients but in only 1 (3%) of their relatives (p = 0.001). The DAT reacted because of IgG alone in 43 percent, complement alone in 5 percent, and IgG plus complement in 19 percent; 33 percent of the patients' cells had a positive reaction with polyspecific reagent only. All 10 ALPS patients with a history of hemolytic anemia had a positive DAT. Sixty percent of them had only IgG on their cells, 30 percent had IgG and complement, and 10 percent reacted only with polyspecific reagent. Of the 11 patients with a positive DAT and no history of hemolytic anemia, IgG alone was present in 27 percent, complement alone in 9%, and IgG plus complement in 9 percent; 55 percent had positive DATs only with polyspecific reagent. Among ALPS patients, those with a positive DAT had greater quantities of cells with increased alpha and ss T-cell receptors that phenotyped as CD4-CD8- and higher IgG levels. CONCLUSIONS: The DAT results in ALPS patients are most similar to those found in warm autoimmune hemolytic anemia. The DAT is useful to distinguish affected and unaffected persons within an ALPS family.     

临床患者血浆中β- 内酰胺类药物＆抗体致输血无效及对供者红细胞亲和力的研究

目的 分析临床患者血浆中β- 内酰胺类药物＆抗体对供者红细胞的亲和力,探究药源性溶血性贫血及输血无效的临床特点。方法 选择2021 年11 月～ 2022 年4 月期间临床送检的4 例有β- 内酰胺类药物用药史的临床患者,检测ABO 与Rh 血型,直接抗球蛋白试验（direct antiglobulin test ,DAT）、不规则抗体鉴定（identification of irregularantibodies,IAT）与β- 内酰胺类药物抗体及效价,对DAT 阳性的患者红细胞进行酸放散并检测放散液中β- 内酰胺类药物抗体。选择ABO 和Rh 同型的供者红细胞与患者血浆在37℃无菌条件下体外致敏,监测β- 内酰胺类药物＆抗体在0 ,24,48 和72 h 与供者红细胞的亲和力,并观察加入补体后的溶血程度。结果 4 例患者血浆中均存在β- 内酰胺类药物抗体,停药前输血无效,停药后输血效果良好。患者1:A 型,RhCCDee,DAT 阳性（3+W）,IAT 阴性,血浆中存在头孢哌酮药物抗体（效价:1∶64）、阿莫西林药物抗体（效价:1∶16）,放散液中存在头孢哌酮药物抗体。患者2:A 型,RhCcDee,DAT 阳性（4+W）,IAT 阴性,血浆中存在头孢哌酮药物抗体（效价:1∶128）,放散液中存在头孢哌酮药物抗体。患者3:A 型,RhCcDee,DAT 阳性（4+）,IAT 阳性,鉴定为抗 E 抗体,血浆中存在阿莫西林药物抗体（效价:1∶16）、亚胺培南药物抗体（效价:1∶64）、头孢哌酮药物抗体（效价:1∶128）,放散液中存在亚胺培南、头孢哌酮药物抗体。患者4:A 型,RhCCDee ,DAT 阳性（1+）,IAT 阳性,鉴定为抗-E.c 抗体,血浆中存在阿莫西林药物抗体（效价:1∶32）,放散液中未检测到药物抗体。4 例患者血浆与供者红细胞体外致敏24 h 后DAT均为阳性,48 和72 h 内逐渐增强,加入补体后均可引起红细胞溶解。结论 头孢哌酮、阿莫西林和亚胺培南三种β-内酰胺类药物＆抗体可迅速结合到供者红细胞表面并随时间延长而增强,有补体存在的条件下可在24 ～ 72 h 内破坏供者红细胞引起溶血,导致输血无效。