Osimertinib in uncommon EGFR exon 21 L861R and EGFR exon 18 deletion-insertion mutant non-small cell lung cancer-case report.

Background: Tyrosine kinase inhibitors (TKIs) have changed the treatment landscape for patients with advanced non-small cell lung cancer (NSCLC) found to have oncogene-driven activating epidermal growth factor receptor (EGFR) mutations. Whilst there have been a handful of case reports of sensitivity to first-generation TKIs in EGFR L861R mutations, the efficacy of the third-generation TKI osimertinib in NSCLC patients with EGFR L861R and EGFR exon 18 deletion-insertion mutations is limited. Case Description: We report two patients from our institution with uncommon EGFR mutations treated with first-line osimertinib. Our first patient, a 72-year-old male with metastatic lung adenocarcinoma was identified to harbour a rare EGFR L861R mutation and was commenced on osimertinib. After a follow-up period of 18 months, the patient is continuing to experience treatment benefit with imaging showing a good partial response. The second patient, a 60-year-old male also with metastatic lung adenocarcinoma and an EGFR exon 18 deletion-insertion mutation achieved a partial response for 6.6 months. Upon progression, he was commenced on carboplatin and pemetrexed chemotherapy however died from subsequent pneumonia. He had an overall survival (OS) from time of diagnosis of 7.6 months. Conclusions: We demonstrate clinical efficacy of first-line osimertinib in the treatment of advanced NSCLC harbouring uncommon EGFR L861R and EGFR exon 18 deletion-insertion mutations. These results may be suggestive of the wider applicability of osimertinib in the treatment of uncommon EGFR mutant NSCLC.

Multifocal, Asymmetric Bilateral Primary Aldosteronism Cannot be Excluded by Strong Adrenal Vein Sampling Lateralization: An International Retrospective Cohort Study.

BACKGROUND: Primary aldosteronism (PA) has been broadly dichotomized into unilateral and bilateral forms. Adrenal vein sampling (AVS) lateralization indices (LI) ≥2 to 4 are the standard-of-care to recommend unilateral adrenalectomy for presumed unilateral PA. We aimed to assess the rates and characteristics of residual PA after AVS-guided adrenalectomy. METHODS: We conducted an international, retrospective, cohort study of patients with PA from 7 referral centers who underwent unilateral adrenalectomy based on LI≥4 on baseline and/or cosyntropin-stimulated AVS. Aldosterone synthase (CYP11B2) immunohistochemistry and next generation sequencing were performed on available formalin-fixed paraffin-embedded adrenal tissue. RESULTS: The cohort included 283 patients who underwent AVS-guided adrenalectomy, followed for a median of 326 days postoperatively. Lack of PA cure was observed in 16% of consecutive patients, and in 22 patients with lateralized PA on both baseline and cosyntropin-stimulated AVS. Among patients with residual PA postoperatively, 73% had multiple CYP11B2 positive areas within the resected adrenal tissue (versus 23% in those cured), wherein CACNA1D mutations were most prevalent (63% versus 33% in those cured). In adjusted regression models, independent predictors of postoperative residual PA included Black versus White race (odds ratio, 5.10 [95% CI, 1.45-17.86]), AVS lateralization only at baseline (odds ratio, 8.93 [95% CI 3.00-26.32] versus both at baseline and after cosyntropin stimulation), and CT-AVS disagreement (odds ratio, 2.75 [95% CI, 1.20-6.31]). CONCLUSIONS: Multifocal, asymmetrical bilateral PA is relatively common, and it cannot be excluded by robust AVS lateralization. Long-term postoperative monitoring should be routinely pursued, to identify residual PA and afford timely initiation of targeted medical therapy.

Ependymoma-like tumor with mesenchymal differentiation (ELTMD) with ZFTA:NCOA1 fusion: A diagnostic challenge.

Ependymal tumors are classified based on their location, histology, and molecular characteristics. Supratentorial ependymomas (ST-EPNs) are a group of circumscribed supratentorial gliomas, which usually have pathogenic fusions involving either zinc finger translocation associated (ZFTA) (formerly C11orf95) or YAP1. A subtype of ependymoma was recently described and labeled ependymoma-like tumors with mesenchymal differentiation (ELTMDs). We describe a case of a 5-year-old boy who presented with a right frontal tumor. The diagnosis was challenging, and a correct diagnosis could only be reached after reanalysis of methylation data with a more recent version of the classifier and RNA fusion testing, which revealed ZFTA:NCOA1 (nuclear receptor coactivator 1) fusion. There are only a handful of cases of this entity, which is being reported for its rarity and the diagnostic challenge it poses.

Cellular myofibromas with SRF fusions: clinicopathological and molecular study of 3 cases of a rare entity and a potential mimic of sarcoma.

Cellular myofibromas/myopericytomas harboring recurring SRF fusions are recently characterized as rare and diagnostically challenging entities, which can mimic myogenic sarcomas. These tumors belong to the pericytic/perivascular myoid tumor family, which comprises a group of genetically heterogenous and sometimes morphologically overlapping entities. In this series, we describe 3 cases of SRF-rearranged cellular myofibromas/perivascular myoid tumors with a smooth muscle-like phenotype in children. The children ranged from 7 to 16 years of age, and all presented with a painless mass in the extremities, 2 of which were deep-seated. Histologically, the tumors demonstrated a smooth muscle-like morphology and immunophenotype with mild atypia and low-level mitotic activity. Prominent dense collagen deposition and coarse calcification was observed in 2 tumors. RNA sequencing revealed SRF fusions in all cases, with each tumor showing a different 3' partner gene, RELA, NFKBIE, and NCOA3. Of these, NCOA3 has not been reported previously, and this expands the molecular spectrum by identifying a novel fusion partner for SRF. Given that histological features can be worrisome for a myogenic sarcoma, wider awareness of this emerging tumor is valuable to avoid potential misclassification.

Clear Cell Sarcoma of the Kidney (CCSK) With BCOR-CCNB3 Fusion: A Rare Case Report With a Brief Review of the Literature.

Pediatric renal tumors are a rare entity and majority of these tumors are accounted for by Wilms tumor. The second most common renal tumor is clear cell sarcoma of the kidney (CSSK). Most of the CSSK have either BCOR-internal tandem duplication (ITD) or YWHAE-NUTM2B/E fusion. The sarcomas with BCOR-CCNB3 fusion are well documented in soft tissue and bone tumors, but are extremely rare in the pediatric renal setting. We are reporting an extremely rare case of pediatric clear cell sarcoma of the kidney (CSSK) with BCOR-CCNB3 fusion, which was a diagnostic challenge on morphological grounds. A final diagnosis could only be reached after multiple reviews and NGS based RNA fusion testing. We have also performed a brief review of literature which revealed eight (8) other cases of this rare entity.

Laboratory Diagnosis of ANCA-Associated Vasculitis (AAV) Using a Combination of Immunofluorescence Test (IIFT) and Line Immunoassay (LIA): Single-Centre Report From India.

INTRODUCTION: Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a small vessel vasculitis with insufficient epidemiological estimates in India. We aimed to determine demographic, clinical features, and laboratory diagnosis of AAV patients presenting to a large tertiary care centre in India. MATERIAL AND METHODS: 1289 patient samples were screened for ANCA by indirect immunofluorescence test (IIFT) and confirmation of ANCA target antigens was done by line immunoassay. Association between IIFT and LIA was determined in AAV. RESULTS: By IIFT, ANCA was detected in 13.0% (168 out of 1289), of which 23.8% (40/168) were positive with P-ANCA pattern, 25.0% (42/168) were positive with C-ANCA and 47.6% (80/168) showed an atypical pattern. On evaluation with a line immunoassay, 6.7% (86/1289) were positive out of which 52.3% (45/86), 41.9% (36/86), 8.8% (6/86) were positive for anti-MPO, anti-PR3, and anti-GBM respectively. In eosinophilic granulomatosis with polyangiitis (EGPA) 87.5% (7/8), and microscopic polyangiitis (MPA/RLV) 91.3% (21/23), anti-MPO was the predominantly observed antibody. In granulomatosis with polyangiitis (GPA) anti-PR3 antibody was predominant in 87.5% (28/32) cases. Out of 168 IIF positive samples 8, 32, and 23 cases of EGPA, GPA, and MPA/RLV were observed respectively. CONCLUSIONS: The primary aim of the study was to provide single-centre data to determine the laboratory diagnosis of AAV. A combination of IIFT and LIA was found to be an optimum testing strategy for the laboratory diagnosis of AAV.

Laboratory Diagnosis of ANCA-Associated Vasculitis (AAV) Using a Combination of Immunofluorescence Test (IIFT) and Line Immunoassay (LIA): Single-Centre Report From India / Diagnóstico de laboratorio de vasculitis asociada a ANCA (VAA), utilizando conjuntamente test de inmunofluorescencia (IIFT) e inmunoensayo lineal (LIA): Reporte de un único centro de la India

Introduction: Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a small vessel vasculitis with insufficient epidemiological estimates in India. We aimed to determine demographic, clinical features, and laboratory diagnosis of AAV patients presenting to a large tertiary care centre in India. Material and methods: 1289 patient samples were screened for ANCA by indirect immunofluorescence test (IIFT) and confirmation of ANCA target antigens was done by line immunoassay. Association between IIFT and LIA was determined in AAV. Results: By IIFT, ANCA was detected in 13.0% (168 out of 1289), of which 23.8% (40/168) were positive with P-ANCA pattern, 25.0% (42/168) were positive with C-ANCA and 47.6% (80/168) showed an atypical pattern. On evaluation with a line immunoassay, 6.7% (86/1289) were positive out of which 52.3% (45/86), 41.9% (36/86), 8.8% (6/86) were positive for anti-MPO, anti-PR3, and anti-GBM respectively. In eosinophilic granulomatosis with polyangiitis (EGPA) 87.5% (7/8), and microscopic polyangiitis (MPA/RLV) 91.3% (21/23), anti-MPO was the predominantly observed antibody. In granulomatosis with polyangiitis (GPA) anti-PR3 antibody was predominant in 87.5% (28/32) cases. Out of 168 IIF positive samples 8, 32, and 23 cases of EGPA, GPA, and MPA/RLV were observed respectively. Conclusions: The primary aim of the study was to provide single-centre data to determine the laboratory diagnosis of AAV. A combination of IIFT and LIA was found to be an optimum testing strategy for the laboratory diagnosis of AAV.(AU)

Introducción: La vasculitis asociada a anticuerpos anticitoplasma de neutrófilos –ANCA– (VAA) es una vasculitis de pequeños vasos con cálculos epidemiológicos insuficientes en India. Nuestro objetivo fue determinar las características demográficas y clínicas, y los diagnósticos de laboratorio de los pacientes con VAA que se presentaron en un gran centro de cuidados terciarios en India. Material y métodos: Se realizó un cribado de ANCA en 1.289 pacientes mediante test de inmunofluorescencia directa (IIFT), realizándose la confirmación de los antígenos diana de ANCA mediante inmunoensayo lineal. La asociación entre IIFT y LIA fue determinada en VAA. Resultados: Mediante IIFT, se detectó ANCA en el 13% de los pacientes (168 de 1.289), de los cuales, el 23,8% (40/168) fue positivo con el patrón P-ANCA, el 25% (42/168) fue positivo con C-ANCA y el 47,6% (80/168) reflejó un patrón atípico. En la evaluación con inmunoensayo lineal, el 6,7% (86/1.289) fue positivo, de los cuales, el 52,3% (45/86), 41,9% (36/86) y 8,8% (6/86) fueron positivos para anti-MPO, anti-PR3 y anti-GBM, respectivamente. En la granulomatosis eosinofílica con poliangitis (EGPA), en el 87,5% (7/8) de los casos, y en poliangitis microscópica (MPA/RLV) en el 91,3% (21/23), anti-MPO fue el anticuerpo predominantemente observado. En granulomatosis con poliangitis (GPA), el anticuerpo anti-PR3 fue predominante en el 87,5% (28/32) de los casos. De entre 168 muestras positivas de IIF, se observaron 8, 32, y 23 casos de EGPA, GPA y MPA/RLV, respectivamente. Conclusiones: El objetivo primario del estudio fue aportar los datos de un único centro para determinar el diagnóstico de laboratorio de VAA. El resultado fue que la combinación de IIFT y LIA es una estrategia óptima para el diagnóstico de laboratorio de VAA.(AU)

Prozone phenomenon in pretransplant testing: An interesting conundrum involving solid-phase and cell-based assays.

BACKGROUND: Human leukocyte antigen (HLA) is a major determinant in deciding upon solid organ histocompatibility. Donor-specific anti-HLA antibodies (Donor-specific anti-HLA antibodies (DSAs)) are always a contraindication for solid organ transplantation, and identification of DSA becomes very crucial before transplantation to provide long-term graft survival. For identification of DSA, usually, either cell-based or HLA bead-based assay is being used in laboratories. However, both cell-based and bead-based assays have certain limitations. One such common limitation is "prozone effect," which can give false-negative results. Here, we would like to present a small pilot study to analyze the effect of the prozone phenomenon in the cell-based and HLA bead-based assays and its utility in histocompatibility testing. MATERIALS AND METHODS: In a series of four experiments, cell-based assay, flow cytometric cross-match (FCXM), and HLA bead-based flow cytometric panel reactive antibodies (PRAs) were performed. Single-antigen bead (SAB) testing was conducted as a first experiment on four known positives samples for anti-HLA antibody-antibodies. In the second experiment, these four samples were pooled together (called pooled sera in the text) and tested for FCXM and PRA. In the third experiment, known commercially available positive control sera were mixed with pooled positive sera (positive control sera + pooled sera) to prepare, what we have called "positive concoction" in the text. In the fourth experiment, the positive concoction was diluted serially (1:2, 1:4, 1:8, and 1:16) and FCXM and PRA were performed again to analyze and compare the prozone effect. RESULTS: Pooled sera did not have the expected median fluorescence intensity (MFI) values in FCXM assay, whereas the PRA was showing >90% positivity. In positive concoction, the MFI of FCXM assay was observed to be declining; however, PRA values remained almost constant. Dilutions of the pooled sera showed that MFI values of FCXM assays were increased suddenly after dilution. The highest MFI values were observed in 1:4 dilution of the sera, and then, it declined gradually, but the PRA values remained almost constant even after serial dilutions. CONCLUSION: In our experimental findings, it was clear that cell-based assay (FCXM) was more severely affected by the prozone, whereas solid-phase (flow PRA) assay remained resistant to prozone.

Laboratory Diagnosis of ANCA-Associated Vasculitis (AAV) Using a Combination of Immunofluorescence Test (IIFT) and Line Immunoassay (LIA): Single-Centre Report From India.

INTRODUCTION: Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a small vessel vasculitis with insufficient epidemiological estimates in India. We aimed to determine demographic, clinical features, and laboratory diagnosis of AAV patients presenting to a large tertiary care centre in India. MATERIAL AND METHODS: 1289 patient samples were screened for ANCA by indirect immunofluorescence test (IIFT) and confirmation of ANCA target antigens was done by line immunoassay. Association between IIFT and LIA was determined in AAV. RESULTS: By IIFT, ANCA was detected in 13.0% (168 out of 1289), of which 23.8% (40/168) were positive with P-ANCA pattern, 25.0% (42/168) were positive with C-ANCA and 47.6% (80/168) showed an atypical pattern. On evaluation with a line immunoassay, 6.7% (86/1289) were positive out of which 52.3% (45/86), 41.9% (36/86), 8.8% (6/86) were positive for anti-MPO, anti-PR3, and anti-GBM respectively. In eosinophilic granulomatosis with polyangiitis (EGPA) 87.5% (7/8), and microscopic polyangiitis (MPA/RLV) 91.3% (21/23), anti-MPO was the predominantly observed antibody. In granulomatosis with polyangiitis (GPA) anti-PR3 antibody was predominant in 87.5% (28/32) cases. Out of 168 IIF positive samples 8, 32, and 23 cases of EGPA, GPA, and MPA/RLV were observed respectively. CONCLUSIONS: The primary aim of the study was to provide single-centre data to determine the laboratory diagnosis of AAV. A combination of IIFT and LIA was found to be an optimum testing strategy for the laboratory diagnosis of AAV.

mtDNA Analysis: A Valuable Tool to Establish Relationships in Live Related Organ Transplants.

INTRODUCTION: In India, 90% kidneys for transplantation are obtained from living donor while only 10% come from deceased donors. Since the rate of living organ donors is high, it therefore leads to the problem of organ trafficking.To minimize the chances of organ trafficking, the Transplantation of Human Organ Act (THOA) 2014 was enacted in India that makes it mandatory to prove the relationship between patient and donor by DNA testing. The present study was undertaken to evaluate the degree of matching between maternally related patients and donors, performed using mitochondrial DNA (mtDNA). METHODS: After taking an informed consent, a total of 84 subjects were recruited in the study, 42 kidney transplant recipients and 42 their corresponding donors. An attempt was made to establish and confirm the claimed relationship betweenrecipient and donor using mtDNA analysis. RESULTS: Out of the total 42 cases, mtDNA analysis supported the claimed relationship in 33 (78.57%) cases, whereas in 9 (21.42%) cases claimed relationship could not be supported. CONCLUSION: mtDNA can be used as valuable tool to support the claimed relationships of maternal lineage. It is important that more and more organ transplant physicians, surgeons and committees are made aware of this diagnostic modality.

A guide to organize voluntary stem cell donors recruitment drive for hematopoietic progenitor stem cell transplant.

BACKGROUND: Hematopoietic progenitor cell transplantation (HPCT) is used as a definitive treatment in hematological malignancies. For a successful HPCT, the donor and recipient should have matching human leukocyte antigens (HLAs). About 25% of patients have a chance of finding matching HLA within family, while rests 75% are dependent on voluntary stem cell donor. Globally, there are 75 stem cell registries with more than 30 million donors registered among which India represents 0.36 million. Therefore, finding a stem cell donor for Indian patient is quite difficult. The aim of the present study is to discuss the significance of voluntary stem cell donor recruitment drive and also to guide the drive organizers and their team for effectively organizing the drive to increase the database of such donors. MATERIALS AND METHODS: Voluntary stem cell donor recruitment drives are conducted to spread awareness among the people and motivate them to register as a donor. Once the donors have given their consent, the sample is taken and sent to laboratory for HLA typing and the result is uploaded in World Marrow Donor Association, an international association of member to find the best possible matches for patients with hematological disorders. RESULTS: Genebandhu has organized over 127 recruitment camps since 2012 and recruited 13,000 voluntary stem cell donors. HLA typing of 7446 donors has been completed. Out of this small number of typed donors, 11 lifesaving HPCTs have been successfully facilitated. CONCLUSIONS: Here, we have demonstrated guidelines along with steps to organize voluntary stem cell donors recruitment drive that is needed to increase number of donors, thus increasing significantly the chances of saving many vital lives.

Matched unrelated donor hematopoietic progenitor cell transplantation: A report based on a single registry in India.

INTRODUCTION: Currently, more than 10,000 matched unrelated donor transplants (MUDT) are performed annually worldwide. India has recorded a significant increase in the number of hematopoietic progenitor cell transplantation (HPCT) centers reporting transplants. The number of HPCTs increases by approximately 10% every year, with 1878 transplants reported by Indian stem cell transplant registries in 2016. However, published outcome data of MUDT in India are scant, with reports limited to autologous and allogenic matched unrelated transplants, which motivated us to present our MUDT data. AIMS AND OBJECTIVE: To review the operations, and more importantly, the patient outcome data of a new registry in India. MATERIALS AND METHODS: We accessed an Indian HLA donor database with high-resolution HLA typing results of 7682 (until 31st July 2018) volunteer HLA donors. The typing results were uploaded to proprietary software. The search result was considered a "match" when a 10/10 potential HLA match was found. Patients who were found to be alive through mail communication and did not exhibit signs and symptoms of disease were considered to have disease-free survival (DFS). RESULTS: During the six years of operations of the database, 1165 searches resulted in 68 10/10 matches from the registry. Of these, 11 were MUD HPCT records. At a minimum follow-up of almost 11 months, seven recipients continue to exhibit DFS. CONCLUSIONS: The patient DFS data prove that even a small registry with slightly more than 7000 donors can yield reasonably good patient outcomes.

Assessment of plasma cell myeloma minimal residual disease testing by flow cytometry in an international inter-laboratory study: Is it ready for primetime use?

BACKGROUND: Minimal/measurable residual disease (MRD) testing by flow cytometry (FC) has been proposed as a potential surrogate clinical endpoint in plasma cell myeloma (PCM) clinical trials. As a result, effort has gone into standardizing this approach on PCM patients. AIMS: To assess inter-laboratory variation in FC MRD testing of PCM patients in an independent inter-laboratory study. METHODS: A dilution series of five stabilized bone marrow samples manufactured to contain 0%, 0.1%, 0.01%, 0.001%, and 0.0001% neoplastic plasma cells (PCs) were tested blind, using standardized FC PCM MRD assays by 10 international laboratories. RESULTS: Laboratories' assays broadly adhered to the consensus guidelines; however, some deviations were identified in panel design, fluorochrome conjugates, and lysis reagents. Despite this, all laboratories that returned results detected neoplastic PCs down to 0.001% of leucocytes. 6/8 laboratories detected neoplastic PCs at a level of 0.0001%. Quantitative data returned by laboratories showed good consensus and linearity with increasing variation at lower levels of MRD. However, examples of analytical and post analytical error were identified. SUMMARY/CONCLUSION: Broadly standardized PCM MRD FC assays can attain the lower limit of detection (LOD) required by current and future clinical trials, an important consideration in establishing PCM MRD testing as a surrogate clinical marker in PCM clinical trials. Laboratories' assays showed good linearity, encouraging the prediction of survival based on log reduction in neoplastic PC populations in future clinical trials. However, the deviations from consensus guidelines identified in this study would suggest that if PCM MRD assays are further standardized interlaboratory variation could be reduced. © 2018 International Clinical Cytometry Society.

CD326 (EpCAM) testing by flow cytometric BerEP4 antibody is a useful and rapid adjunct to histopathology.

Flow cytometry has been traditionally used to diagnose leukaemia and lymphoma in peripheral blood, bone marrow, body fluids, and tissue samples. The diagnosis of a malignant epithelial tumour is usually made by correlation between histopathologic appearance and the use of immunohistochemical staining. A CE approved BerEP4 antibody (anti-EpCAM, CD326) is available for flow cytometric testing, but has been evaluated predominantly in body fluids in the current literature. In this study, we have evaluated the performance of this antibody in detecting the presence of epithelial cells in tissue samples which have traditionally been reported as CD45 negative cells by flow cytometry. Among the 42 cases studied, 21 (50%) were found to be positive for CD326, thereby suggesting epithelial differentiation. The results had good concordance rates (97.6%) with final histopathological diagnosis. The results clearly show that flow cytometric testing for BerEP4 (CD326) can be a useful method for diagnosing nonhaematological malignancies that are poorly differentiated. As this is a rapid method for identifying epithelial differentiation, it can help the histopathologists tailor and rationalise the immunohistochemical panel, with the potential benefits of improving reporting times and work-flow in the laboratory. © 2017 International Clinical Cytometry Society.

False negative single antigen bead assay: Is it always an effect of prozone?

BACKGROUND: Bead based flow cytometry and Luminex play a major role in identification of alloantibodies in renal transplant work-up. Strong sensitization events may lead to prozone phenomenon that can affect single antigen bead (SAB) assay and result in false negativity. However, this can also be due to high titer of other blocking antibodies. While methods like, heat inactivation, C1 inhibitor, Ethylene diamine tetra-acetic-acid and Dithio threitol treatment can remove interfering antibodies of complement and IgM, these methods are not optimal if false negativity is due to prozone effect, which is high titer of antibodies alone. METHODS: We hereby present a case of a highly sensitized renal transplant recipient with 64% panel reactive antibody positivity (PRA) and a subsequent negative SAB assay. This paradoxical finding hinted at SAB being a false negative result and serial dilutions were used to perform further tests. RESULTS: Serum dilutions lead to positive flow based panel reactive antibody (PRA) and flow cytometry crossmatch (FCXM), with an increasing trend in FCXM. CONCLUSIONS: In highly sensitized patients serial dilution should be considered during a transplant work-up to avoid missing any underlying antibodies. Serum dilution can be used as first option to circumvent prozone. Also, interference of other antibodies should not be labeled as prozone effect.

Detection of T and B cells specific complement-fixing alloantibodies using flow cytometry: A diagnostic approach for a resource limited laboratory.

BACKGROUND AND OBJECTIVES: Various methods have been reported for the detection of antibodies in recipient sera, which can be human leukocyte antigens (HLAs) or non-HLA specific, complement- or noncomplement fixing, as well as donor T (HLA-Class-I) and/or B cell (HLA-Class-I and II) specific. These alloantibodies play a pivotal role in antibody-mediated renal transplantation rejection. Deposition of C4d in peritubular capillaries of a kidney biopsy is a marker of antibody-mediated rejection. The C4d flow-panel reactive antibodies (PRAs) are a screening method for HLA-specific and complement fixing antibodies. However, the method is limited by the lack of donor specificity. DESIGN AND SETTINGS: Here, we present a new and simple flow cytometric method referred to as C4d-flow cytometry crossmatch (C4d-FCXM) for the detection of donor-specific (T and/or B cell) and C4d-fixing alloantibodies. RESULTS: The method was applied in a series of clinical cases and judged to be useful. The method may limit unwanted deferral of the donor due to positivity in C4d Flow-PRA and/or FCXM and may be helpful in prediction of antibody mediated rejections. Furthermore, this method can provide information pretransplant in contrast to kidney biopsy and C4d evaluation done posttransplant. CONCLUSIONS: We postulate that this method incorporates most of the features of all the available modalities (i.e., National Institute of Health-complement dependent lymphocytotoxicity, FCXM, cytotoxic FCXM and C4d-flowPRA) yet cost-effective and best suited for resource-limited laboratory/ies which is a common scenario in developing countries.