Red cell immunization in multiply transfused Malay thalassemic patients

The development of red blood cell (RBC) isoimmunization with alloantibodies and autoantibodies complicate transfusion therapy in multiply transfused thalassemia patients. Thus, the frequency, causes and prevention of these phenomena were studied among these patients. Clinical and serological data from 58 Malay multiply transfused thalassemic patients who sought treatment at Hospital University Sains Malaysia were collected and analyzed prospectively. Blood samples were subjected to standard blood bank procedures to screen for antibody and subsequent antibodies identification. All patients in our hospital received blood matched for only ABO and Rh (D) antigens. There were 46 (79.3%) patients with Hb E/beta thalassemia, 8 (13.8%) with beta thalassemia major, 3 (5.2%) with Hb H Constant Spring and 1 (1.7%) with Hb H disease. Overall, 8.6% of the patients had alloantibodies and 1.7% had autoantibodies. The alloantibodies identified were anti-E, anti-c, anti-K, anti-Jka, anti-N and anti-S. In conclusion, the transfusion of matched blood is essential for chronically multiply transfused patients in order to avoid alloimmunization. Considering the high frequency of anti E at our hospital, it is advisable to genotype patients and match the red cells for E antigens in multiply transfused thalassemia patients.     

Red Blood Cell Antibodies in Thalassemia Patients in Northern India: Risk Factors and Literature Review

Study of the factors responsible for red cell alloimmunization can help in adopting appropriate strategy to minimize alloimmunization. However data for thalassemia patients from our region is limited. Therefore, a study was conducted to find out the frequency and the factors associated with red cell allo and autoimmunization in thalassemia patients at our center so as to enable us to take appropriate action to reduce alloimmunization. Clinical, demographic, allo and autoantibody and transfusion records of 280 thalassemia patients at our hospital were studied. Patients with and without alloantibodies were compared to find significant differences for age, gender, race, age at start of regular transfusions and splenectomy. Red cell antigen frequencies in thalassemia patients and published antigen frequencies in blood donors from the same center were compared to look antigen differences as a risk factor for alloimmunization. Twenty four thalassemia patients (8.6 %) developed 28 clinically significant alloantibodies. 18 (65 %) of the alloantibodies were of Rh system. The three most common antibodies detected was anti E (11, 39.3 %) followed by anti K (6, 21.4 %) and anti c (10.8 %). Five (1.8 %) of the 280 patients developed autoantibodies. Patient age was found to be significantly higher in alloimmunized patients than in non alloimmunized patients. Red cell antigen frequencies between blood donor and recipient populations were found to be homogenous for most of the relevant RBC antigens. The frequency of red cell alloimmunization in thalassemia patients from our center is moderate. In this setting of red cell phenotype concordant donor–recipient population requirement of extended phenotype matched transfusions may not be cost effective.     

Incidence of Red Cell Alloantibody among the Transfusion Recipients of Universiti Kebangsaan Malaysia Medical Centre

Red blood cell alloimmunization is a common complication among the transfusion recipients. In Malaysia, multiple ethnicity causes genetic heterogeneity among the population which in turn can cause a wide variation of antibody. The objective of this study was to analyse the red cell alloantibody detected during the pre-transfusion testing. This was a cross-sectional study done in the blood bank of Universiti Kebangsaan Malaysia Medical Centre during the period of January–December 2010. The data was retrieved from the hospital laboratory information system. A total of 24,263 patients’ blood samples were subjected for pre-transfusion testing. Antibody screening was done using an indirect antiglobulin test method. The positive samples were further identified for antibody specificity. Antibody screening tests were positive in 184 patients out of 24,263 samples with the incidence of 0.76 %. Autoantibodies and alloantibodies were detected in 39/184 (21.2 %) and 140/184 (76.1 %) of the patients respectively. In five patients (2.7 %) the antibody specificity remained undetermined. Total 161 alloantibodies were identified. The suspected Anti-Mia alloantibody was observed most frequently (49/161, 30.4 %) followed by anti-E (30/161, 18.6 %) and anti-D (22/161, 13.7 %). Anti-E and anti-c were the most common combination of multiple alloantibodies. In view of the high incidence of suspected Anti-Mia antibodies, more efforts are needed to look into the techniques for confirmation of the Anti-Mia antibodies. Besides that, we suggested that all multiply transfused patients should be phenotyped for the Rh system and to supply Rh phenotype specific blood in order to limit alloimmunization.     

Prevalence,Specificity and Titration of Red Cell Alloantibodies in Multiparous Antenatal Females at a Tertiary Care Centre from North India

Screening and detection of clinically significant antibodies among antenatal women plays an important role in transfusion safety and preventing hemolytic disease of fetus and newborn. Routine screening of antenatal women for antibodies is not done in all blood centres of our country and so immunization rates are not known in pregnant women. We studied the prevalence of alloantibodies and titration of Anti D among antenatal multiparous women in Jammu region. In present prospective study, 750 antenatal multiparous women attending antenatal clinics were typed for ABO and D antigens. Alloantibody screening was done, if positive, specificity of alloantibody was ascertained by using commercially available red cell panel by tube method. Rate of alloimmunization was correlated with Rh D status, gravida, previous transfusion history and bad obstetric history. Titration of alloantibody D was done in first and third trimester of pregnancy. In present study most common blood group detected was B positive (38.4 %). Rh D negative cases constituted 7.6 % of total cases. Rate of alloimmunization was 2 %. A significant correlation was seen between Rh D-negative and alloimmunization (21 % in D-negative and 0.45 % in D-positive). There is significant increasing degree of alloimmunization with increase in Gravida. Alloimmunization in females with bad obstetric history was high (4.41 %) as compared to females with no bad obstetric history showing only 1.76 %. Alloantibodies detected were Anti-D, Anti-E, Anti-C and Anti-K. Anti-D constituted 80 % of all alloantibodies detected. Six women in their third trimester had raised titers of anti-D. Most common alloantibody detected was anti-D (80 %). Alloantibodies to other Rh antigens and Kell blood group systems were also identified. To minimize alloimmunization in Rh D negative women, proper Anti D immunoprophylaxis should be implemented.     

Prevalence and clinical significances of red cell alloimmunization and red cell bound immunoglobulin G in polytransfused patients with thalassemias

The study was to determine the prevalence and clinical significances of red blood cell (RBC)-bound IgG as detected by flow cytometry in polytransfused patients with thalassemias. Relationship of the presence of RBC-bound IgG with RBC alloimmunization was also evaluated. This study included 59 polytransfused patients with β-thalassemia disease. We studied the frequency of RBC autoantibodies and alloimmunization. Direct Coombs test and flow cytometry were performed to detect the presence of RBC autoantibodies while RBC alloantibodies were detected by antibody screening and identification assays.

Eight (13.6%) and 34 (57.6%) patients were found a positive direct Coombs test and flow cytometry, respectively. Twenty (33.9%) patients developed RBC alloantibodies. The four most frequent RBC alloantibodies were anti-E (55%), anti-Mia (40%), anti-Di(a) (25%) and anti-c (15%), respectively. There was no significant difference in the presence of RBC-bound IgG between polytransfused with thalassemia patients who developed RBC alloimmunization (13 of 20; 65%) and those without RBC alloantibodies (21 of 39; 53.8%), p?=?0.412. Splenectomy and increased transfusion requirement were significantly associated with the presence of RBC-bound IgG but not with RBC alloantibody formation.

The overall frequency of RBC alloantibody formation in polytransfused patients with thalassemias was 33.9%. The most common RBC alloantibody was anti-E. RBC autoantibody formation was more frequently detected by flow cytometry (57.6%) than by direct Coombs test (13.6%). Splenectomy was significantly associated with the development of autoreactive RBC-bound IgG antibodies in the polytransfused patients with thalassemias. The presence of the anti-RBC autoantibodies may cause an increase of transfusion requirement.     

Rh antibodies as a result of altered Rh epitopes on transfused red cells: a case series of seven Brazilian patients

BackgroundRh antibodies produced by patients receiving Rh-matched RBC units may be associated with inheritance of altered RH alleles or a result of altered Rh epitopes on donor red blood cells (RBC). On this background, our aim was to evaluate unexpected Rh antibodies in Brazilian patients receiving regular transfusions and determine the clinical significance of the alloantibody produced.Material and methodsWe investigated seven patients (5 with sickle cell disease, 1 with myelodysplastic syndrome and 1 with β-thalassaemia) with unexplained Rh antibodies. All patients had complete serological and molecular analyses. A lookback at the donor units transfused to these patients was performed and donors suspected of having Rh variants were recruited for further analysis. Laboratory and clinical findings were used to evaluate the clinical significance of the alloantibodies produced.ResultsThe unexpected Rh antibodies found in the patients were not linked to the expression of partial Rh phenotypes according to serological and molecular analyses. Anti-D was found in two patients, anti-C was found in one patient, anti-c was found in one patient and anti-e was found in three patients carrying conventional D, C, c and e antigens respectively. Serological and molecular analyses of donors’ samples revealed that six donors whose RBC were transfused to these patients carried partial Rh antigens. Only one anti-e in a patient with β-thalassaemia was autoreactive and could not be explained by RH diversity in his donors. Three of the seven Rh antibodies were associated with laboratory and clinical evidence of a delayed haemolytic transfusion reaction or decreased survival of transfused RBC at first detection.DiscussionOur study provides evidence that patients exposed to RBC units from donors with Rh variants may develop antibodies and some of these may be of clinical significance.     

Alloimmunization and erythrocyte autoimmunization in transfusion-dependent thalassemia patients of predominantly asian descent

The development of hemolytic alloantibodies and erythrocyte autoantibodies complicates transfusion therapy in thalassemia patients. The frequency, causes, and prevention of this phenomena among 64 transfused thalassemia patients (75% Asian) were evaluated. The effect of red blood cell (RBC) phenotypic differences between donors (mostly white) and Asian recipients on the frequency of alloimmunization was determined. Additional transfusion and patient immune factors were examined. 14 (22%) of 64 patients (75% Asian) became alloimmunized. A mismatched RBC phenotype between the white population, comprising the majority of the donor pool, and that of the Asian recipients, was found for K, c, S, and Fyb antigens, which accounts for 38% of the alloantibodies among Asian patients. Patients who had a splenectomy had a higher rate of alloimmunization than patients who did not have a splenectomy (36% vs 12.8%; P =.06). Erythrocyte autoantibodies, as determined by a positive Coombs test, developed in 25% or 16 of the 64 patients, thereby causing severe hemolytic anemia in 3 of 16 patients. Of these 16, 11 antibodies were typed immunoglobulin G [IgG], and 5 were typed IgM. Autoimmunization was associated with alloimmunization and with the absence of spleen (44% and 56%, respectively). Transfused RBCs had abnormal deformability profiles, more prominent in the patients without a spleen, which possibly stimulated antibody production. Transfusion of phenotypically matched blood for the Rh and Kell (leukodepleted in 92%) systems compared to blood phenotypically matched for the standard ABO-D system (leukodepleted in 60%) proved to be effective in preventing alloimmunization (2.8% vs 33%; P =.0005). Alloimmunization and autoimmunization are common, serious complications in Asian thalassemia patients, who are affected by donor-recipient RBC antigen mismatch and immunological factors.     

Characteristics of Different Rhesus Alloantibodies in Lymphocyte Dependent (K Cell) Cytotoxicity to Human Erythrocytes

The property of rhesus alloantibodies to elicit antibody-dependent, cell-mediated cytotoxicity (ADCC) against target erythrocytes carrying various Rh genotypes was studied. The killer activity of normal peripheral lymphocytes on human erythrocyte target cells carrying the appropriate antigens elicited by alloantisera was measured by 51Cr release at 18 h. There was no correlation between ADCC and antibodies directed to the antigens present on the surface of different genotypes of Rh-positive red blood cells. The agglutinin titre of different Rh antibodies showed no correlation with the level of ADCC although the degree of cellular cytotoxicity was different with different anti-D sera. Anti-C + D+ E antibody caused higher ADCC than anti-C + D and the lowest cytotoxicity was observed with anti-D and anti-D+ E. This raised the possibility that ADCC was elicited by antibodies directed to other specificities. K cell lysis of human red cells by human peripheral blood lymphocytes in vitro suggests that a similar mechanism may operate in vitro in the destruction of erythrocytes coated by allo or autoantibodies.     

RBC alloimmunization in blood transfusion-dependent beta-thalassemia patients in southern Iran

beta-thalassemia is considered a severe, progressive anemia, which needs regular transfusions for life expectancy. One of the most important complications of regular blood transfusions may be alloimmunization, which increases the need for transfusion. This study was performed to investigate the production of red cell alloantibodies in beta-thalassemia patients in Shiraz, southern Iran. Blood sampling was performed among 711 beta-thalassemia patients in Dastgheib hospital in 2002-2004. Direct and indirect coombs tests were performed to check the auto and alloantibodies and a panel test was conducted to detect the type of alloantibodies. Auto and alloantibodies were observed among 1.7% and 5.3% of patients, respectively. The most common alloantibodies were Anti-kell (50%) > Anti-Rh (D) (15.8%) > Anti-Rh (E) (10.5%). All the patients who had developed alloantibody were in the age group of 6 years or more. So for decreasing the rate of alloantibody synthesis, we should crossmatched the packed cells for minor blood groups especially for kell and Rh(E) in addition to major blood groups from the start of transfusion.     

Polyreactivity of Human Monoclonal Antibodies: Human Anti-Rh Monoclonal Antibodies of IgM Isotype Are Frequently Polyreactive

The specific aim of this study was to characterize human anti-Rh monoclonal antibodies cross-reacting with self-antigens. We studied supernatants from man-mouse hybridomas and from lymphoblastoid cell lines. Man-mouse hybridomas were established by fusion of peripheral blood lymphocytes from healthy individuals recently immunized against Rh alloantigens, with mouse myeloma (or man-mouse heteromyeloma) cell lines. Lymphoblastoid cell lines were produced by Epstein-Barr virus induction of lymphocytes from identical sources. Of the 55 monoclonal alloantibodies studied, 11 also reacted with intracellular self-antigens as demonstrated by immunofluorescence assay on cryostat sections of human tissues. This cross-reactivity was mainly a property of monoclonal alloantibodies belonging to the IgM isotype (among the 11 cross-reacting mAbs 10 were IgM). The cross-reactivities of these monoclonal antibodies were ascertained by absorption of alloreacting antibodies with red blood cells. Similar results were obtained on a panel of purified cellular antigens by ELISA. The results confirm that during an immune response against a foreign antigen (alloantigen), B cells that produce polyreactive antibodies are not excluded from the pool of responding cells. Therefore, polyreactive autoantibodies present in sera from healthy individuals may be the result of an immune response against foreign antigens.     

Immune hemolytic anemia associated with negative routine serology

Immune hemolytic anemia can occur in patients who have no antibodies detectable by routine procedures (direct [DAT] and indirect [IAT] antiglobulin tests). DAT-negative autoimmune hemolytic anemias (AIHAs) represent 5% to 10% of all AIHAs. Three causes have been identified: (1) small numbers of red blood cell (RBC)-bound IgG molecules below the threshold of the DAT; (2) IgA and IgM autoantibodies; and (3) low-affinity autoantibodies. Antibody-independent cytotoxic events caused by natural killer (NK) cells have also been implicated. DATs are sometimes found to be positive when tested by reference laboratories, due to poor technique in reading antiglobulin tests in hospital laboratories. Hemolytic transfusion reactions also can occur when no alloantibodies are detectable by routine procedures. In some cases antibodies can be detected by special serologic procedures (such as the Polybrene test); in other instances phenotypically matched RBCs survive well and a specific antigen can be shown to be involved, suggesting a specificity (like anti-C) that is undetectable by any technique. Antibodies other than to blood group antigens, such as human leukocyte antigen (HLA) antibodies, may sometimes be involved.     

Critical Re-examination of the Specificity of Auto-anti-Rh Antibodies in Patients with a Positive Direct Antiglobulin Test

Forty-eight autoantibodies with apparent 'simple' anti-Rh specificity (anti-e, -E, -c, -D, -C, -Ce, -G), have been studied by means of multiple absorption tests. The finding that 34 (70.8%) of these antibodies could bind to red blood cells lacking the antigens that the antibodies appeared to define, indicated that the antibodies had different specificities than seemed to be the case in initial antibody identification tests. Those autoantibodies that at first appeared to be directed against the Rh antigens e, E or c, most often had anti-Hr or anti-Hro specificity. These data explain why some apparent anti-Rh autoantibodies can be eluted from the red blood cells of patients negative for the antigens that the antibodi:s appear to define. However, they also illustrate that the phenomenon of autoantibodies mimicking specificities that they do not possess is common in patients positive for the antigens against which their autoantibodies appear to be directed. An explanation for the mode of action of these autoantibodies in complexing with the Rh agglutinogen is proposed, and the significance of the antibodies in transfusion therapy is considered.     

Red cell antibodies in frequently transfused patients with myelodysplastic syndrome

Therapy for myelodysplastic syndrome (MDS) is often restricted to lifelong support with red blood cell units (RBCU). A variety of immune phenomena associated with antibody production have been reported in MDS patients. Therefore, we hypothesized that red cell antibodies are more frequent in patients with MDS compared to other regularly transfused patients. Red cell antibodies were determined in 42 MDS patients, in 28 patients with other hematological disorders, and in a historical group of 129 patients with end-stage renal failure. All of these patients received frequent red cell substitution therapy, at least two RBCU in biweekly intervals. Red cell antibodies were detected in 9 of 42 patients with MDS, in 3 of 28 patients with other hematological disorders, and in 4 of 129 patients with end-stage renal failure. Evidence of red cell antibodies was displayed by 6 of 27 MDS patients treated with prestorage leukocyte-depleted RBCU and 3 of 15 MDS patients transfused with bedside leukocyte-filtered RBCU. Red cell antibodies are frequent in patients with hematological disorders who require repetitive red cell transfusions. The formation of alloantibodies to red cell antigens is as frequent in MDS patients as in other patients with hematological disorders.     

Detection and Identification of Red Cell Alloantibodies in Multiply Transfused Thalassemia Major Patients: A Prospective Study

Life long red blood transfusion remains the main treatment for β thalassemia major patients. The development of alloantibodies complicates transfusion therapy in thalassemia patients. Alloimmunization to red cell antigens is one of the most important immunological transfusion reaction and causes delayed type of transfusion reaction. A prospective study was conducted from January 2007 to January 2010. This was a cohorts of 115 patients were selected from regular transfusion group and they were followed for two and half year. They were followed up for the effect of transfusion during study period. There was a decline in patient number from 115 to 96 due to mortality and transfer of patient. A total of 96 multiply transfused thalassemia patients were prospectively included in this study and three consecutive samples collected after every 6 months and investigated for the development of alloantibody to red cell antigens. Tests for antibody screening and identification were performed on preserved sample to investigate prevalence and development of red cell alloimmunization by standardized laboratory techniques by same person at Prathama Blood Centre. A total of 96 patients were included in the study. 63 patients were males and 33 females. A total of five single alloantibodies were formed in five patients out of them four (80 %) belonged to Kell blood group system and one (20 %) from Rh system. It was observed that two (1.92 %) of new thalassemia patients developed red cell alloantibodies during study period. Red cell alloimmunization should be kept in mind in the patients receiving multiple transfusions. In present study, alloimmunization rate was 5.21 %. Mean transfusion duration in these patients was 23.90 days, probably due to presence of alloantibody. RBC alloantibody detection on regular interval and corresponding antigen negative blood transfusion is strongly recommended in transfusion dependent thalassemia patients.     

Enhancement of Antibody Titre and Development of Additional Red Cell Alloantibodies Following Intrauterine Transfusion

Intrauterine blood transfusion is the mainstay of managing foetuses with severe anemia. It may however result in fetomaternal hemorrhage, which in cases of Rh isoimmunisation may increase the severity of the disease by enhancing the maternal immunological response to fetal antigens. This study was conducted to determine the frequency, specificity and origin of additional red cell antibodies which developed after IUT. The change in the titre of allo anti-D following IUT was also determined. Antibody detection and titration was done on the blood samples of all the patients before and after intrauterine blood transfusion to check for the development of additional antibody and change in the titre of existing anti-D. Severe anemia was found in 17 (58.6 %) fetuses who received a total of 42 ultrasound-guided IUTs. Development of antibodies additional to anti-D in maternal serum was seen in 5 (29.4 %) cases. The specificity of additional alloantibodies was anti-C in four cases whereas it was anti-E in one case. Four fold or greater increase in existing allo-anti D titre was seen in 6 (35.3 %) cases after IUT. Enhancement of maternal sensitisation leading to an increase in maternal antibody titre is particularly seen after the first IUT. Matching of the donor RBCs particularly for Rh antigens might prevent the induction of additional alloantibodies against these antigens. IUT as a treatment modality should be given judiciously and only when the need is inevitable.     

输血与血型不规则抗体检测的关系

目的：探讨输血与血型不规则抗体检测的关系。方法：用卡式凝胶法对4790例输血患者的备血样本进行血型不规则抗体检测并进行输血史调查;阳性标本加传统的试管抗人球蛋白法做比较。结果：检出不规则抗体总阳性率为0．71％,其中自身抗体6例,同种特异性抗体26例;3次以上输血组与3次以下输血组比较检出不规则抗体阳性率差异有统计学意义（P〈0．05）,卡式凝胶法检出抗体阳性率与传统的试管抗人球蛋白法比较差异有统计学意义（P〈0．05）。结论：不规则抗体产生与输血频率关系密切;输血前作不规则抗体检测和鉴定在保障临床手术或药物治疗及安全有效输血中具有重要临床意义;选用卡式凝胶法检测不规则抗体,其灵敏度高,结果可靠,操作简便,值得临床推广常规应用。     

Two distinct categories of warm autoantibody reactivity with age-fractionated red cells

Using age-fractionated erythrocytes, warm autoantibodies can be classified into two distinct categories, depending on their reactivity with reticulocyte-enriched (younger) or reticulocyte-poor (older) red cell fractions. The strength of the direct antiglobulin test (DAT) on the age-fractionated red cells of 24 patients indicated that 19 (79%) had an IgG warm autoantibody that reacted preferentially with older red blood cells. In 7 of these 19 patients (37%), the DAT was negative using reticulocyte-enriched red cell fractions. We have termed this preferential reactivity of warm autoantibodies with older red cells as type I. Five of the 24 patients studied (21%) had an IgG warm autoantibody that demonstrated no preference for young or older red cells. We have termed this pattern of warm autoantibody reactivity as type II. All 5 patients having type II warm autoantibodies had severe anemia. In contrast, 6 of 19 patients having type I warm autoantibody did not have clinical evidence of anemia when tested, and 11 of the 19 had only slight to moderate anemia. Additionally, our results using type I warm autoantibody raise questions regarding the blood group specificity of warm autoantibodies. The antigen recognized by type I warm autoantibody may be a cryptantigen. Rh specificity or relative Rh specificity, often associated with warm autoantibodies, may simply be a coincidental finding.     

Granulocyte‐reactive antibodies are associated with red blood cell alloimmunization

Granulocyte‐reactive antibodies may cause transfusion‐related acute lung injury (TRALI) and immune neutropenias. Risk factors for their acquisition other than previous alloexposition are largely unknown. In addition to the known association between human leucocyte antigen alloantibodies and red blood cell alloimmunization in selected cohorts of transfused patients, this study investigated a possible extension of this association to granulocyte‐reactive antibodies in women with a history of pregnancy. The overall prevalence of granulocyte‐reactive antibodies in 333 samples from women with a history of pregnancy (143 samples containing red cell alloantibodies) was 23·1%. The prevalence in the red cell‐alloimmunized group (32·9%) was significantly higher than in controls (15·8%, P < 0·001). This could suggest that some individuals may be strong immunological responders, forming alloantibodies more readily than others.     

Utility of adsorption techniques in serological evaluation of warm autoimmune haemolytic anaemia

Background

Various adsorption techniques are available to remove serum autoantibodies and subsequently detect the underlying alloantibody in previously transfused patients with autoimmune haemolytic anaemia. We planned to establish a suitable adsorption technique in our transfusion service which can remove all autoantibodies and detect underlying alloantibodies rapidly, cheaply and effectively.

Study design and methods

We evaluated 71 direct antiglobulin test-reactive patients with warm AIHA over a period of 20 months. Twenty-three of these 71 patients who had a previous history of blood transfusion or pregnancy and were confirmed carriers of autoantibodies (indirect antiglobulin test-reactive) were considered for the adsorption study. Depending on the adequacy of samples, history of blood transfusion and severity of anaemia either autoadsorption or alloadsorption or both using polyethylene glycol (PEG) or low ionic strength saline (LISS)-papain were performed.

Results

Underlying alloantibodies were detected in 7 of the 23 patients (30.4%) and all these were specific to Rhesus antigens. The mean number of alloadsorptions for complete autoantibody removal using PEG was 1.43 which was significantly lower than the 3.9 using the LISS-papain method (p<0.05). The mean time required by PEG alloadsorption and LISS-papain alloadsorption for autoantibody removal was 93.6 minutes and 177.7 minutes, respectively (p<0.05). Discordant results were not observed in any case and identical alloantibodies were detected by both the techniques.

Conclusion

We found that the PEG method is a rapid, cheap and effective way to remove autoantibodies and detect underlying alloantibodies.