deBGR: an efficient and near-exact representation of the weighted de Bruijn graph

MOTIVATION

Almost all de novo short-read genome and transcriptome assemblers start by building a representation of the de Bruijn Graph of the reads they are given as input. Even when other approaches are used for subsequent assembly (e.g. when one is using 'long read' technologies like those offered by PacBio or Oxford Nanopore), efficient k -mer processing is still crucial for accurate assembly, and state-of-the-art long-read error-correction methods use de Bruijn Graphs. Because of the centrality of de Bruijn Graphs, researchers have proposed numerous methods for representing de Bruijn Graphs compactly. Some of these proposals sacrifice accuracy to save space. Further, none of these methods store abundance information, i.e. the number of times that each k -mer occurs, which is key in transcriptome assemblers.

RESULTS

We present a method for compactly representing the weighted de Bruijn Graph (i.e. with abundance information) with essentially no errors. Our representation yields zero errors while increasing the space requirements by less than 18-28% compared to the approximate de Bruijn graph representation in Squeakr. Our technique is based on a simple invariant that all weighted de Bruijn Graphs must satisfy, and hence is likely to be of general interest and applicable in most weighted de Bruijn Graph-based systems.

AVAILABILITY AND IMPLEMENTATION

https://github.com/splatlab/debgr .

CONTACT

rob.patro@cs.stonybrook.edu.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Phenotypic and genotypic characterization of phosphate solubilizing bacteria and their efficiency on the growth of maize

Phosphate solubilizing bacteria (PSB) has ability to convert insoluble form of phosphorous to an available form. Applications of PSB as inoculants increase the phosphorus uptake by plant in the agriculture field. In this study, isolation and identification of PSB were carried out in Indian agriculture field (Nainital region, Uttarakhand). A total of 8 phosphate solubilizing bacterial colonies were isolated on the Pikovskaya’s (PKV) agar medium, containing insoluble tricalcium phosphate (TCP). The colonies showed clear halo zones around the bacterial growth were considered as phosphate solubilizers. Out of 8 bacterial isolates, 3 isolates showed high phosphate solubilization index (PSI) ranged from 4.88 ± 0.69 to 4.48 ± 0.30, lower pH ranging 3.08 ± 0.08 to 3.82 ± 0.12 and high phosphate solubilization varied from 305.49 ± 10 μg/ml to 277.72 ± 1.45 μg/ml, were selected for further characterization. Based on the 16 S rRNA gene sequence analysis A4 isolate and H6 isolate were closely related to Alcaligenes aquatilis (99%), and C1 isolate was closely related to Burkholderia cepacia (99%). In addition, pot examination also showed the greatest efficiency in promotion of maize growth compared to uninoculated plant. Isolated PSB were able to produce different organic acids (such as gluconic acids, formic acid, and citric acid) in the culture supernatant and may consider as the principle mechanism for phosphate solubilization. This study clearly indicates that A4, C1 and H6 isolates may use as a biofertilizers in ecological agricultural systems instead of synthetic chemicals and may help to sustain environmental health and soil productivity.

Measurement of the Neutrino Mixing Angle θ_{23} in NOvA

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3}  eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

Data collection using open access technology in multicentre operational research involving patient interviews

Conducting multicentre operational research is challenging due to issues related to the logistics of travel, training, supervision, monitoring and troubleshooting support. This is even more burdensome in resource-constrained settings and if the research includes patient interviews. In this article, we describe an innovative model that uses open access tools such as Dropbox, TeamViewer and CamScanner for efficient, quality-assured data collection in an ongoing multicentre operational research study involving record review and patient interviews. The tools used for data collection have been shared for adaptation and use by other researchers.

Free radicals hasten head and neck cancer risk: A study of total oxidant, total antioxidant, DNA damage, and histological grade

Background:

Free radicals such as reactive oxygen species (ROS), which induce oxidative stress, are the main contributors to head and neck carcinogenesis (HNC). The present study was conducted with the aim to assess the oxidant/antioxidant status and DNA damage analysis in head and neck cancer/control patients.

Materials and Methods:

This prospective study was conducted on 60 patients with biopsy-proven HNC and 17 patients of head and neck disease (HND). The total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were determined by novel automatic colorimetric methods from tissue homogenate. DNA damage analysis was determined by single cell gel electrophoresis (SCGE).

Results:

The mean age of the study cohort was 46.65 ± 14.84 years for HNC patients, while it was 49.41 ± 13.00 years for HND patients. There were no significant differences found between the two groups with respect to demographic presentation except tobacco addiction. The association between oxidative stress parameters and DNA damage analysis with study group revealed the following. (A) DNA damage - tissue homogenate TOS and OSI were significantly higher in HNC subjects than in HND (16.06 ± 1.78 AU vs 7.86 ± 5.97 AU, P < 0.001; 53.00 ± 40.61 vs 19.67 ± 21.90, P < 0.01; 7.221 ± 5.80 vs 2.40 ± 2.54, P < 0.01, respectively), while TAS was significantly decreased. (B) Aggressive histological features were identified, more commonly with higher TOS and lower TAS [probability (P) = 0.002, relative risk (RR) = 11.838, 95% confidence interval CI = 2.514-55.730 and P = 0.043, RR = 0.271, 95% CI = 0.077-0.960, respectively].

Conclusion:

The increase in free radicals may be the event that led to the reduction of antioxidant status in HNC, thus explaining the oxidative damage of DNA and the severity of disease. Increased OSI represents a general mechanism in its pathogenesis.

A high yield DNA extraction method for medically important Candida species: A comparison of manual versus QIAcube-based automated system

The prognosis of infected individuals with candidemia depends on rapid and precise diagnosis which enables optimising treatment. Three fungal DNA extraction protocols have been compared in this study for medically important Candida species. The quality and quantity of the DNA extracted by physical, chemical and automated protocols was compared using NanoDrop ND-2000 spectrophotometer. It was found that the yield and purity (260/230) ratio of extracted DNA was significantly high in the physical treatment-based protocol as compared to chemical based or automated protocol. Extracted DNA-based real time-polymerase chain reaction showed an analytical sensitivity of 103 cfu/mL. The result of this study suggests physical treatment is the most successful extraction technique compared to other two protocols.

Linitis plastica like primary signet ring cell carcinoma of the gallbladder - an extremely rare variant

Signet ring carcinoma (SRCC) of gallbladder is an extremely rare tumor accounting for approximately 3% of all gallbladder carcinomas, with a handful of case reports in the literature. We report a case of signet ring cell carcinoma of the gallbladder in a 70 year-old female who was operated upon after the preoperative diagnosis of cholecystitis with cholelithiasis, based on ultrasonographic findings and subsequently diagnosed as signet ring cell carcinoma of the gallbladder on histopathological examination. Grossly there was no discrete growth, instead tumor presented as linitis plastica like diffuse thickening of the gallbladder wall. Microscopic examination revealed a diffusely infiltrative carcinoma comprised exclusively of signet ring cells and confirmed by periodic acid-Schiff (PAS), Alcian blue & Cytokeratin 7 stains. Post -operative clinico-radiological workup was done to exclude secondary. This highly aggressive signet ring cell carcinoma of gallbladder is being reported because of its rarity, its unique histomorphological features and diagnostic inadequacy of the routinely performed ultrasonography as well as highlighting the use of special stains and immunohistochemistry to exclude other possibilities. Our case highlights that routine histopathological examination of all the cholecystectomy specimens is a must to facilitate the early diagnosis of aggressive signet ring cell carcinoma gallbladder.

Predicting Salmonella Typhimurium reductions in poultry ground carcasses

To improve understanding of Salmonella Typhimurium LT2 inactivation in ground poultry carcasses, a series of experiments were carried out at multiple temperatures. Subsequently, a non-linear model was developed to predict Salmonella inactivation at composting and low rendering temperatures. The Salmonella inactivation study was conducted using bench-top experiments at 38, 48, 55, 62.5, 70, and 78°C in mixed and non-mixed reactors using ground poultry carcasses as a feedstock. Subsequently, these observations were used for developing a non-linear model. The model predictions were compared with the observations of a different set of experiments. The comparisons among predictions and observations showed that the model predictions are reasonable and can be useful to determine the time required for Salmonella inactivation in poultry carcasses at multiple temperatures. Results showed that at composting conditions, when temperature varies between 48 and 62.5°C, Salmonella survival can prolong between 10,000 and 25,000 min (7 to 17 d). If ambient temperature is maintained at low temperature rendering range (70 to 78°C), then Salmonella survival can last for 90 to 120 minutes. We anticipate that this study will help in improving the existing understanding of Salmonella survival in poultry carcasses.

First Measurement of Electron Neutrino Appearance in NOvA

We report results from the first search for ν_{μ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

Molecular genetics of essential hypertension

Hypertension is a major public health problem in the developing as well as in developed countries due to its high prevalence and its association with coronary heart disease, renal disease, stroke, peripheral vascular disease, and related disorders. Essential hypertension (EH) is the most common diagnosis in this disease, suggesting that a monocausal etiology has not been identified. However, a number of risk factors associated with EH have also been identified such as age, sex, demographic, environmental, genetic, and vascular factors. Recent advances in molecular biological research had achieved clarifying the molecular basis of Mendelian hypertensive disorders. Molecular genetic studies have now identified mutations in several genes that cause Mendelian forms of hypertension in humans. However, none of the single genetic variants has emerged from linkage or association analyses as consistently related to the blood pressure level in every sample and in all populations. Besides, a number of polymorphisms in candidate genes have been associated with differences in blood pressure. The most prominent candidate has been the polymorphisms in the renin-angiotensin-aldosterone system. In total, EH is likely to be a polygenic disorder that results from inheritance of a number of susceptibility genes and involves multiple environmental determinants. These determinants complicate the study of blood pressure variations in the general population. The complex nature of the hypertension phenotype makes large-scale studies indispensable, when screening of familial and genetic factors was intended. In this review, recent genetic studies exploring the molecular basis of EH, including different molecular pathways, are highlighted.

Autologous peripheral blood stem cell harvest: Collection efficiency and factors affecting it

BACKGROUND

Harvest of hematopoietic progenitor cells via leukapheresis is being used increasingly for transplants in India. Adequate yield of cells per kilogram body weight of recipient is required for successful engraftment. Collection efficiency (CE) is an objective quality parameter used to assess the quality of leukapheresis program. In this study, we calculated the CE of the ComTec cell separator (Fresenius Kabi, Germany) using two different formulae (CE1 and CE2) and analyzed various patient and procedural factors, which may affect it.

MATERIALS AND METHODS

One hundred and one consecutive procedures in 77 autologous donors carried out over 3 years period were retrospectively reviewed. Various characteristics like gender, age, weight, disease status, hematocrit, preprocedure total leukocyte count, preprocedure CD34 positive (CD34+) cells count, preprocedure absolute CD34+ cell count and processed apheresis volume effect on CE were compared. CE for each procedure was calculated using two different formulae, and results were compared using statistical correlation and regression analysis.

RESULTS

The mean CE1 and CE2 was 41.2 and 49.1, respectively. CE2 appeared to be more accurate indicator of overall CE as it considered the impact of continued mobilization of stem cells during apheresis procedure, itself. Of all the factors affecting CE, preprocedure absolute CD34+ was the only independent factor affecting CE.

CONCLUSION

The only factor affecting CE was preprocedure absolute CD34+ cells. Though the mean CE2 was higher than CE1, it was not statistically significant.

Correlation between two chemiluminescence based assays for quantification of hepatitis B surface antigen in patients with chronic hepatitis B infection

PURPOSE

Hepatitis B surface Antigen (HBsAg) is the hallmark in diagnosing hepatitis B virus (HBV) infection. In India many commercial assays are available for detection of HBsAg but very few can measure it quantitatively. The present study presents the comparative evaluation of two methods and their correlation with serum HBsAg in chronic hepatitis B (CHB) patients.

MATERIALS AND METHODS

Consecutive patients of CHB were included and there HBsAg levels were measured by two methods: (i) Elecsys, Roche Diagnostics, a qualitative assay and (ii) Architect, Abbott Diagnostics, a quantitative assay. The HBV DNA was measured by real-time polymerase chain reaction (qPCR).

RESULTS

Total of 136 patients were included in the study and there was a significant overall correlation between both the assays (correlation coefficient [r] = 0.83; P < 0.001). Assays correlated well with each other across all subgroups of CHB: treatment naοve (r = 0.73; P < 0.001, n = 32), on treatment (r = 0.56; P < 0.05, n = 104), hepatitis Be (HBe) antigen positive (r = 0.67; P < 0.001, n = 62) and anti-HBe positive (r = 0.61; P < 0.05, n = 74) group. On correlation with serum HBV DNA, Architect assay demonstrated good correlation (r = 0.73; P < 0.001, n = 136) as compared to the Elecsys assay (r = 0.27; P = 0.068, n = 136). Architect HBsAg QT assay (A1) also correlated well with HBV DNA in the treatment naοve group (r = 0.69; P < 0.001, n = 32).

CONCLUSIONS

Our study hence proved that both the assays are comparable and a simple qualitative assay with in-house modification can be used easily for quatitation of HBsAg in clinical samples.

A comprehensive serological and supplemental evaluation of hepatitis B "seroyield" blood donors: A cross-sectional study from a tertiary healthcare center in India

Background:

The present study addressed the interesting findings of supplemental evaluation of hepatitis B “seroyield” donors.

Materials and Methods:

Each blood donor sample was tested for anti-human immunodeficiency virus type I (HIV-I)/HIV type II (HIV-II), HBsAg, and anti-hepatitis C virus (HCV) antibody by enhanced chemiluminescence method and subjected to individual donor-nucleic acid testing (NAT) for HIV-I, hepatitis B virus (HBV), and HCV. NAT test was performed using the eSAS system, Procleix Ultrio Assay, Novartis Diagnostics, CA, US. Confirmation of HBsAg was done using HBsAg Confirmatory Kit (Ortho Clinical Diagnostics, Johnson & Johnson, USA) and viral load assessment was done using Cobas TaqMan real time-polymerase chain reaction (RT-PCR) assay (Roche Molecular Systems, Branchburg, NJ, USA). To provide information on the stage of infection, specimens were tested for anti-HBc total (IgG + IgM), anti-HBc IgM and HBeAg. HBeAg-negative samples were tested for anti-HBe antibody.

Results:

A total of 60 hepatitis B seroyield donors which showed mean initial sample/cutoff of 1.6 with enhanced chemiluminescence assay were investigated further for confirmation of disease status. All 60 cases were confirmed positive with neutralization assay (VITROS HBsAg Confirmatory Kit) while no target was detected on viral load assessment with RT-PCR. Sixteen donors were HBeAg positive (4 IgM anti-HBc positive and 12 IgM anti-HBc negative) and 44 were IgM anti-HBc negative, anti-HBc total positive, and anti-HBe positive.

Conclusion:

About 7.7% of HBsAg positive and NAT nonreactive donors (nondetectable HBV DNA) could be potentially infectious (HBeAg positive), whereas rest of the donors were consistent with chronic HBV infection.

α-Solanine induces ROS-mediated autophagy through activation of endoplasmic reticulum stress and inhibition of Akt/mTOR pathway

α-Solanine is a glycoalkaloid found in species of the nightshade family including potato. It was primarily reported to have toxic effects in humans. However, there is a growing body of literature demonstrating in vitro and in vivo anticancer activity of α-solanine. Most of these studies have shown activation of apoptosis as the underlying mechanism in antitumor activity of α-solanine. In this study, we report α-solanine as a potential inducer of autophagy, which may act synergistically or in parallel with apoptosis to exert its cytotoxic effect. Induction of autophagy was demonstrated by several assays including electron microscopy, immunoblotting of autophagy markers and immunofluorescence for LC3 (microtubule-associated protein 1 (MAP1) light chain-3) puncta. α-Solanine-induced autophagic flux was demonstrated by additionally enhanced – turnover of LC3-II and – accumulation of LC3-specific puncta after co-incubation of cells with either of the autophagolysosome inhibitors – chloroquine and – bafilomycin A1. We also demonstrated α-solanine-induced oxidative damage in regulating autophagy where pre-incubation of cells with reactive oxygen species (ROS) scavenger resulted in suppression of CM-H₂DCFDA (5 (and 6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate acetyl ester) fluorescence as well as decrease in LC3-II turnover. α-Solanine treatment caused an increase in the expression of endoplasmic reticulum (ER) stress proteins (BiP, activating transcription factor 6 (ATF6), X-box-binding protein 1, PERK, inositol-requiring transmembrane kinase/endonuclease 1, ATF4 and CCAAT-enhancer-binding protein (C/EBP)-homologous protein) suggesting activation of unfolded protein response pathway. Moreover, we found downregulation of phosphorylated Akt (Thr³⁰⁸ and Ser⁴⁷³), mammalian target of rapamycin (mTOR; Ser²⁴⁴⁸ and Ser²⁴⁸¹) and 4E-BP1 (Thr^37/46) by α-solanine implying suppression of the Akt/mTOR pathway. Collectively, our results signify that α-solanine induces autophagy to exert anti-proliferative activity by triggering ER stress and inhibiting Akt/mTOR signaling pathway.

Pea lectin receptor-like kinase functions in salinity adaptation without yield penalty, by alleviating osmotic and ionic stresses and upregulating stress-responsive genes

Lectin receptor-like kinases (LecRLKs) are members of RLK family composed of lectin-like extracellular recognition domain, transmembrane domain and cytoplasmic kinase domain. LecRLKs are plasma membrane proteins believed to be involved in signal transduction. However, most of the members of the protein family even in plants have not been functionally well characterized. Herein, we show that Pisum sativum LecRLK (PsLecRLK) localized in plasma membrane systems and/or other regions of the cell and its transcript upregulated under salinity stress. Overexpression of PsLecRLK in transgenic tobacco plants confers salinity stress tolerance by alleviating both the ionic as well the osmotic component of salinity stress. The transgenic plants show better tissue compartmentalization of Na(+) and higher ROS scavenging activity which probably results in lower membrane damage, improved growth and yield maintenance even under salinity stress. Also, expression of several genes involved in cellular homeostasis is perturbed by PsLecRLK overexpression. Alleviation of osmotic and ionic components of salinity stress along with reduced oxidative damage and upregulation of stress-responsive genes in transgenic plants under salinity stress conditions could be possible mechanism facilitating enhanced stress tolerance. This study presents PsLecRLK as a promising candidate for crop improvement and also opens up new avenue to investigate its signalling pathway.

Approach to a case of multiple irregular red cell antibodies in a liver transplant recipient: Need for developing competence

Liver transplant procedure acts as a challenge for transfusion services in terms of specialized blood components, serologic problems, and immunologic effects of transfusion. Red cell alloimmunization in patients awaiting a liver transplant complicate the process by undue delay or unavailability of compatible red blood cell units. Compatible blood units can be provided by well-equipped immunohematology laboratory, which has expertise in resolving these serological problems. This report illustrates resolution of a case with multiple alloantibodies using standard techniques, particularly rare antisera. Our case re-emphasizes the need for universal antibody screening in all patients as part of pretransfusion testing, which helps to identify atypical antibodies and plan for appropriate transfusion support well in time. We recommend that the centers, especially the ones that perform complex procedures like solid organ transplants and hematological transplants should have the necessary immunohematological reagents including rare antisera to resolve complex cases of multiple antibodies as illustrated in this case.

Abstract 4521: P7170, a novel inhibitor of phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) and activin receptor-like kinase 1 (ALK1) shows anti-tumor activity in triple negative breast cancer

Triple negative breast cancer (TNBC) lacks ER, PR and Her2 receptor expression & accounts for nearly 10-15% of all breast cancer. It is an aggressive disease with high risk for early relapse & visceral metastasis leading to poor survival as compared to other subtypes. Currently, there is no targeted therapy beyond cytotoxic chemotherapy for TNBC. PI3K-mTOR pathway is often dysregulated (via mutations in PI3K or PTEN) in TNBC and hence offers an opportunity to develop a therapeutic to address the high unmet medical need in this disease. P7170, a small molecule mTOR/PI3K/ALK1 inhibitor with potent antitumor activity in various cancer types {Cancer Res, April 15,2012; 72(8 Supplement): 3742 and 3759} is currently undergoing Phase 1 clinical trial. Here, we report the evaluation of anti-tumor activity and the identification of potential pharmacodynamic markers of P7170 in a TNBC model. P7170 inhibited proliferation (IC50 range 5 - 38 nmol/L) in TNBC cell lines as determined using propidium iodide (PI) assay. In addition, P7170 inhibited anchorage-independent growth of tumor cells isolated from patient derived tumor xenografts evaluated in a clonogenic assay. PI3K-mTOR pathway proteins pS6 and p4EBP1 were potently inhibited whereas pAkt was modestly inhibited by P7170 in MDA-MB-231 cells as assessed by Western blot. It also inhibited migration of MDA-MB-231 cells in a transwell migration assay. P7170 at 1/3rd dose of Maximum tolerated dose (5 mg/kg, po) as a single agent resulted in 63% (P&lt;0.05) tumor growth inhibition in MDA-MB-231 xenograft mouse model. Pharmacodynamic effects of P7170 were evaluated in the plasma, tumor and skin of MDA-MB-231 tumor bearing mice treated with

P7170 (5 and 15 mg/kg) orally for 3 days. Expression of target genes was measured by qRT-PCR, tumor and skin proteins were measured by immunohistochemistry, and plasma proteins by ELISA. P7170 significantly reduced pS6 protein in a dose-and time-dependent manner in the tumor and skin. P7170 significantly reduced tumor p4EBP1 protein at the highest dose and reduced tumor CDC25A gene by 2-fold. In addition, P7170 dose-dependently reduced plasma IGF1/IGFBP3 ratios compared to vehicle group. Conclusion: These data suggest that P7170 demonstrates robust antiproliferative activities in vitro and anti-tumor activity in vivo in TNBC. Tumor pS6 protein, CDC25A transcript levels and skin pS6 levels were identified as pharmacodynamic markers of P7170 activity. P7170 could be a therapeutic option for TNBC patients, and warrants testing in a clinical trial.

Citation Format: Veena R. Agarwal, Dimple Bhatia, Asavari Joshi, Prabha Mishra, Kalyani G. Bharadwaj, Aurelio S. lobo, Pranoy Menon, Payal Dhar, Prashant Pandey, Sreesha Srinivasa, vinay sonawane. P7170, a novel inhibitor of phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) and activin receptor-like kinase 1 (ALK1) shows anti-tumor activity in triple negative breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4521. doi:10.1158/1538-7445.AM2014-4521

Cascade plasmapheresis (CP) as a preconditioning regime in ABO-incompatible live related donor liver transplants (ABOi-LDLT)

Background

ABO-incompatible live donor liver transplant (ABOi-LDLT) is being widely done to bridge the gap of demand and supply of organs. Different desensitization regimes are being used to reduce titer of blood group antibodies for successful transplant and accommodation of graft. The authors used cascade plasmapheresis (CP) to bring down titer of naturally occurring blood group antibody to 16 or lower.

Material and methods

Four recipients of ABOi-LDLT were of blood groups O, O, B, and B while donors were of blood groups B, A, AB, and AB, respectively. Desensitization protocol included immunosuppressive drugs and plasmapheresis. CP consisted of separating patient’s plasma as the first step and passing it through pore size based filter column as the second step. The first step was performed using disposable kit (PL1, Fresenius Kabi, Germany) with minor modification on apheresis equipment COM.TEC (Fresenius Kabi, Germany). Pore size based filter column used was 2A column (Evaflux, Kawasumi Laboratories, Japan). Blood group antibody titer (immunoglobulin G (IgG)) was done by column agglutination technology (Ortho-Clinical Diagnostics).

Results

Cases 1, 2, 3, and 4 with pre-CP titer of 1,024, 512, 32, and 64 required four, three, one, and one CP procedures, respectively. No signs of antibody-mediated rejection were exhibited on histopathological evaluation by any of the patients. Successful organ engraftment occurred as documented by post-operative liver function tests and liver biopsy.

Conclusion

Cascade plasmapheresis offers a cost-effective and efficient way to decrease blood group antibody titer and helps in successful transplant.