A comparative study between light transmission aggregometry and flow cytometric platelet aggregation test for the identification of platelet function defects in patients with bleeding.

BACKGROUND: Platelet aggregation studies using conventional light transmission aggregometry (LTA) have several disadvantages and require strict pre-analytical measures for reliable results. We aimed to examine the utility of flow cytometric platelet aggregation (FCA) assay in detecting platelet function defects (PFDs) in patients with a history of bleeding symptoms. METHODS: Sixty-four participants (24 patients and 40 healthy controls) were included in this study. LTA and FCA assay were performed simultaneously in patients and healthy controls. In the FCA assay, two portions of platelets from the same individual were labeled separately with CD31-FITC and CD31-PE. After mixing and stimulation with agonists, the double- colored platelet aggregates were visualized using a flow cytometer. The results generated using the two techniques were compared and correlated. RESULTS: The patients' median age was 17 years (range, 3‒72 yr) with a male-to-female ratio of 1:1.7. There was substantial agreement between LTA and FCA assay in detecting a PFD (=0.792). Four patients showing a Glanzmann thrombasthenia-like pattern on LTA exhibited an abnormal FCA. A functional defect in collagen binding was detected on the FCA assay conducted in two immune thrombocytopenic patients with severe bleeding. CONCLUSION: FCA assay can be used to identify functional defects in platelets, with potential applications in thrombocytopenic individuals. It also facilitates the diagnosis of inherited bleeding disorders with platelet defects.

Therapeutic potential of nanolipoidal α-terpineol in combating keratitis induced by Pseudomonas aeruginosa in the murine model.

Developing non-antibiotic alternatives is one of the top priorities in healthcare and community settings, especially for combating biofilm-associated infections caused by multi-drug resistant pathogens. The therapeutic efficacy of nanolipoidal α-terpineol was explored against Pseudomonas aeruginosa induced keratitis using the mice model in the present study. Topical administration of nanostructured lipid carriers (NLCs) containing α-terpineol (αT) resulted in significant reduction in bacterial count in corneal tissue by 4 log10 on 5th post infection day. The protective efficacy of αT-NLCs demonstrated improvement in corneal histopathology, decreased the levels of various inflammatory markers including myeloperoxidase (MPO) and reactive nitrogen intermediates (RNI). Further, αT-NLCs treatment showed immunomodulatory effects by manipulating the production of inflammatory cytokines, tumor necrotic factor (TNF-α), macrophage inhibitory protein-2 (MIP-2) and interleukin-2 (IL-2) in infected eyes. In addition, ex vivo studies exhibited enhanced susceptibility of P. aeruginosa towards serum and macrophages in presence of αT-NLCs. A potent antibiofilm effect was also observed by αT-NLCs against P. aeruginosa which was confirmed by fluorescent microscopic analysis. Hence, based on the results of the present study, a novel therapeutic is being proposed for the treatment of biofilm associated keratitis caused by P. aeruginosa.

Exploring the Therapeutic Efficacy of Zingerone Nanoparticles in Treating Biofilm-Associated Pyelonephritis Caused by Pseudomonas aeruginosa in the Murine Model.

Biofilms of Pseudomonas aeruginosa can cause complicated urinary tract infections especially in people with indwelling catheters which may result in pyelonephritis. Microorganisms in biofilm demonstrate high resistance to both antibiotics and host protection mechanisms, often resulting in chronic and difficult-to-treat infections. This study is aimed to assess in vivo and ex vivo efficacy of Zingerone nanoparticles (Z-NPs) against P. aeruginosa biofilm-associated murine acute pyelonephritis. In the present study, Zingerone and chitosan acted synergistically in the form of Z-NPs and found to be nontoxic to the kidney cell lines as depicted in MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay demonstrating their cytocompatibility. In vivo experiments indicated that Z-NPs (100 mg/kg) treatment reduced P. aeruginosa pathogenicity and enhanced the clearance of bacterial count from the renal and bladder tissue. Z-NPs improved the disease outcome by lowering the levels of various inflammatory markers, and histopathological examination revealed better recovery in renal and bladder tissue. Besides, ex vivo efficacy also confirmed that Z-NPs enhanced serum bactericidal effect along with increased phagocytic uptake and intracellular killing of P. aeruginosa as confirmed by fluorescent microscopy. To the best of our knowledge, this is the first study to provide evidence that Z-NPs are effective therapeutic agents for combating P. aeruginosa associated pyelonephritis.

Nanolipoidal α-terpineol modulates quorum sensing regulated virulence and biofilm formation in Pseudomonas aeruginosa.

Aim:Pseudomonas aeruginosa has emerged as a major opportunistic pathogen meaning there is an immediate need to develop efficient antivirulence agents which offer a new class of superior therapeutics. Methods: Nanostructured lipid carriers (NLCs) containing α-terpineol (αT) were developed and characterized to determine expression profiles of quorum sensing regulated genes, antivirulence activity and antibiofilm effects against P. aeruginosa. Results: The αT-NLCs had a size of 145.4 nm, polydispersity index of 0.242 and ζ-potential of -31.4 mV. They exhibited pronounced effects on the inhibition of quorum sensing mediated virulence and biofilm formation which were confirmed by molecular docking analysis and gene expression profiles. Conclusion: αT-NLCs show promise as effective antivirulence agents against P. aeruginosa in the postantibiotic era.

Terpinen-4-ol attenuates quorum sensing regulated virulence factors and biofilm formation in Pseudomonas aeruginosa.

Aim: To investigate the effects of Terpinen-4-ol on quorum sensing (QS)-regulated biofilm formation and virulence factors production in Pseudomonas aeruginosa. Materials & methods: QS inhibition, molecular docking analysis and gene expression studies were performed to check attenuation effect of Terpinen-4-ol on virulence of P. aeruginosa. Production of various virulence factors and biofilm formation were studied at sub-MIC of Terpinen-4-ol alone and in combination with ciprofloxacin. Results: Terpinen-4-ol at sub-MIC exhibited QS inhibition and downregulated all key QS genes. Molecular docking analysis showed high binding affinities of Terpinen-4-ol with QS receptors. Terpinen-4-ol exhibited synergistic interaction with ciprofloxacin and further reduced production of all the virulence factors and biofilms formation. Conclusion: Terpinen-4-ol could be developed into antivirulence drug after its in vivo evaluation for treatment strategies.

Screening for paroxysmal nocturnal hemoglobinuria (PNH) in patients presenting with cerebral sinovenous thrombosis (CSVT): Results of a FLAER based flowcytometry study in Indian patients.

Patients with paroxysmal nocturnal hemoglobinuria (PNH) may present with thrombosis at unusual sites, of which cerebral sinovenous thrombosis (CSVT) is one and screening for PNH is recommended in this condition. Though many patients diagnosed with PNH develop CSVT, it is unclear how many patients with PNH would present for the first time with thrombosis. We analysed the results of screening for PNH by flowcytometry in our patients with CSVT. The laboratory data of patients referred for thrombophilia and PNH testing in CSVT was examined to assess the frequency of PNH at presentation in these patients. FLAER and CD24 on granulocytes and FLAER and CD14 on monocytes respectively were used to screen the leucocytes for PNH by flowcytometry. The data for Protein C, S and Antithrombin deficiency, antiphospholipid antibodies and the Factor V Leiden mutation was examined and circumstantial risk factors were also assessed. Of the 180 cases of CSVT screened by flowcytometry for PNH, not a single case tested positive. Positivity for anti-phospholipid antibodies was the most common thrombophilic risk factor (5%). Pregnancy was the most common circumstantial risk factor. Our data on FLAER based flowcytometry in the North Indian population with CSVT suggests that PNH is not a common risk factor in our patients with thrombosis at this unusual site.

Acquired Hemophilia A: Experience of a Tertiary Care Institute from North India.

Acquired hemophilia A (AHA) is an uncommon bleeding disorder infrequently reported among Indians. The present retrospective data comprises eight cases of AHA over a period of 15 years. The mean age of patients was 59.7 years. The activated partial thromboplastin time was prolonged in all cases and the inhibitor screen showed the presence of inhibitors. Factor VIII: C assay was performed in 7 cases and all cases demonstrated low levels. Lupus anticoagulant was negative. Six patients were managed with steroids and symptomatic supportive care. These patients were followed up for a mean period of 3.5 years (range 1-5 years). Of these, there was one fatality prior to initiation of therapy and one patient continues to have inhibitors.

Lupus anticoagulant - hypoprothrombinemia syndrome: a rare cause of intracranial bleeding.

: We report a 14-year-old girl who presented with subdural hematoma and a deranged coagulation profile suggestive of an inhibitor. Investigations revealed prothrombin deficiency along with positivity for antiphospholipid antibodies, which improved with steroid therapy. Bleeding diathesis in children and adolescents commonly results from thrombocytopenia, platelet function disorders, or coagulation factor deficiency; whereas bleeding because of coagulation factor inhibitors are extremely rare in this age group. This case also highlights the uncommon presentation of antiphospholipid antibody syndrome, as they often present with thrombosis or pregnancy complications rather than bleeding.

Coagulation factor VIII, IX and XI levels in north Indian patients with venous thromboembolism: first study from India.

Studies have shown elevated levels of certain coagulation factors as risk factors for venous thromboembolism (VTE). In this study, we investigated the levels of coagulation factor VIII (FVIII), FIX and FXI in north Indian patients with VTE. A total of 123 patients with VTE were screened prospectively for FVIII, FIX and FXI levels and the conventional risk factors - deficiencies of protein C, S and antithrombin, positivity for antiphospholipid antibodies and the factor V Leiden mutation. Age-matched and sex-matched controls were included. VTE was secondary to known circumstantial and thrombophilic risk factors in 66 (53.7%) patients. In 46.3% (idiopathic VTE) patients, no cause was identified. The mean FVIII levels in idiopathic (187 IU/dl) and secondary VTE patients (185.4 IU/dl) were significantly higher compared with controls (129.6 IU/dl; P < 0.001). However, there was no statistically significant difference in the levels of FIX and FXI between patients and controls (P = 0.214 and 0.198, respectively). Patients with elevated FVIII levels had increased risk of VTE compared with controls (odds ratio: 9.4, 95% confidence interval: 4.7-18.79). On logistic regression analysis after adjusting for surgery and presence of antiphospholipid antibodies, this risk remained unchanged (odds ratio: 9.54, 95% confidence interval: 4.68-19.44). A dose-response relationship was observed with progressive increase in FVIII levels. Elevated FVIII levels constitute an independent risk factor for VTE in the north Indian population. Elevated levels of FIX and FXI were not associated with increased risk of VTE.

Thrombotic Primary Antiphospholipid Syndrome: the profile of antibody positivity in patients from North India.

AIM: We evaluated the frequency of antiphospholipid antibody syndrome (APS) in patients presenting with thrombosis of various vascular beds from North India and report the antibody profiles encountered. PATIENTS AND METHODS: A retrospective analysis was performed on the laboratory results of aCL (anticardiolipin), aß2 Gp1 (anti-ßeta-2 glycoprotein 1) antibody and LAC (lupus anticoagulant) of 1222 consecutive patients referred to the coagulation laboratory work-up for a hypercoagulable/thrombophilic state over a period of 4 years between 2009 and 2013. LAC was screened with dRVVT (diluted Russel Viper Venom Test) and KCT (Kaolin clotting time), and aCL and aß2 Gp1 antibodies with commercial enzyme-linked immunosorbent assy kits. RESULTS: The current APS criteria was satisfied in 3.85% of all patients and 4.2% of pediatric patients with thrombosis. The venous circulation was more frequently affected (59.6%). Cerebral arterial and intra-abdominal vein involvement was common. Transient antibody positivity was seen in 44 (3.6%) cases. aß2 Gp1, aCL and LAC were positive in 95%, 54.5% and 23% of patients with APS, respectively, during the initial visit and 93.6%, 23% and 17%, respectively, during the follow-up visit. Persistent triple positivity was seen in only three cases. At initial testing, positivity for both aCL and aß2 Gp1 was the most frequent pattern (38% of cases). CONCLUSIONS: aß2 Gp1 antibody was the commonest antibody that was persistently positive in patients with thrombosis. Triple positivity for all antibodies had the highest specificity and positive predictive value to diagnose APS in the first visit, whereas aß2 Gp1 antibody had the highest sensitivity and negative predictive value.

Inherited thrombophilia profile in patients with recurrent miscarriages: Experience from a tertiary care center in north India.

The cause of recurrent miscarriage (RM) remains unexplained in approximately 30% to 50% cases. The association of inherited thrombotic factors and RM patients has not been documented from the northern part of India. A total of 40 patients had been investigated for inherited thrombophilia workup (protein C, protein S [PS], antithrombin III, and factor V Leiden [FVL] mutation) over a period of 10 years (2005 to 2014). RM patients were divided in to three groups. Group I (only 1st trimester loss), group II (only 2nd and 3rd trimester), and group III (mixed). Each group comprised of the following numbers of patients respectively: I, 24; II, 2; III, 14. Heterozygous FVL mutation was found in 10% (4/40) cases. PS deficiency was detected in 2.7% (1/37) cases. In the present study FVL and PS were seems to be associated with a subset of patients however further studies with larger numbers of patients are recommended for better evaluation.

Recurrent hemoperitoneum secondary to haemorrhage from the corpus luteum unmasks factor V deficiency.

Factor V deficiency is a rare autosomal recessive coagulation disorder. We report a case with inherited factor V deficiency presenting as life-threatening recurrent hemoperitoneum, following bleeding from ruptured corpus haemorrhagicum. Prolonged prothrombin and activated partial thromboplastin times, normal thrombin time and a normal platelet count pointed towards a disorder of coagulation. Mixing studies with factor V deficient plasma and coagulation factor assay revealed markedly reduced plasma factor V clotting activity. The management included blood, plasma and tranexamic acid. Family screening revealed low factor V levels in her parents. Although her brother had significant Factor V deficiency and epistaxis, he did not need hospitalization or replacement, indicating the varied manifestation of this bleeding defect in this family.

Thrombophilic risk factors are uncommon in young patients with retinal vein occlusion.

PURPOSE: To study the thrombotic factors, namely deficiencies of plasma proteins C, S, and antithrombin, factor V Leiden mutation, and positivity for antiphospholipid antibodies in young patients with retinal vein occlusion. METHODS: The thrombophilia parameters listed above were analyzed from the laboratory records of 50 patients with the clinical diagnosis of retinal vein occlusion, aged less than 50 years. RESULTS: A single prothrombotic factor was seen in 2 (4%) cases. The highest positivity was for the antiphospholipid antibodies (lupus anticoagulant in 6%, anticardiolipin antibodies in 2%, and anti-ß 2 glycoprotein 1 in 10% cases). Other than one case where antiphospholipid syndrome was confirmed, these were transient. One patient had antithrombin deficiency. Protein C and protein S deficiency and factor V Leiden mutation were not seen in this group. CONCLUSION: Our data suggest that these thrombophilia risk factors are not commonly associated with retinal vein occlusion, and there is a need for studies on other factors that contribute to the development of this condition.

Congenital afibrinogenemia in a new born: a rare cause for bleeding.

Bleeding in the neonates may be a result of thrombocytopenia, sepsis or vitamin K deficiency. Congenital bleeding disorders are a rare cause of bleeding. The umbilical cord bleed is an important clue to underlying bleeding disorders especially factor XIII deficiency and afibrinogenemia. In some laboratories, the routine workup for the bleeding neonate may not always include fibrinogen assays, which may then delay this diagnosis. We report a case of congenital afibrinogenemia in a neonate who presented with umbilical stump bleeding for its rarity and to re-emphasize the need for including fibrinogen assays while assessing a bleeding neonate.

Paroxysmal Nocturnal Hemoglobinuria is rare cause for thrombosis of the intra-abdominal veins in the ethnic Indian population - results from FLAER-based flowcytometry screening.

BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) may present as cytopenia, hemolysis, or thrombosis at unusual sites including splanchnic vessels. Thrombosis of the portal veins and hepatic veins are associated with thrombophilic risk factors: deficiencies of protein C, protein S, and antithrombin, positivity for antiphospholipid antibodies, and factor V Leiden mutation. There is limited information regarding PNH presenting primarily as a thrombotic event. We prospectively screened 142 consecutive patients with intrabdominal thrombosis and 106 controls with fluorescently labeled inactive toxin aerolysin (FLAER)-based flowcytometry to assess the frequency of PNH as a thrombophilic risk factor in patients with intra-abdominal thrombosis. METHODS: Granulocytes of patients and controls were screened with CD 24 and FLAER and monocytes with CD 14 and FLAER. Dual negativity of >1% events in both lineages was interpreted as a positive PNH clone. Screening for thrombophilia risk factors was carried out. RESULTS: Two (1.4%) cases had large PNH clones. RBC also demonstrated the PNH defect. Thrombophilia risk factors were as follows: deficiency of protein S, protein C, and antithrombin in 13.4%, 4.9%, and 2.1%, respectively, and positivity for anti-beta-2 glycoprotein 1, anticardiolipin antibodies, and lupus anticoagulant in 9.2%, 1.4%, and 0.7%, respectively. Factor V Leiden mutation was seen in 1.4% patients. CONCLUSION: PNH was uncommon in patients with intra-abdominal thrombosis in the ethnic Indian population. Despite low positivity, screening by flowcytometry for PNH is of value in this group of patients because it provides an opportunity to rapidly establish the diagnosis of this treatable disorder, which might otherwise be missed if the initial presentation is only thrombotic.

Antiphospholipid antibodies in children with systemic lupus erythematosus: a long-term clinical and laboratory follow-up status study from northwest India.

We have previously shown that children with pediatric systemic lupus erythematosus (pSLE) have high incidence of anti-phospholipid antibodies (APLA) and reports suggest that presence of APLA can modify disease expression. While the frequency of APLA has been studied previously in adults with SLE, there is paucity of literature in children especially with regard to long-term follow-up. In the earlier study, we analyzed 27 pSLE patients for the prevalence of APLA; in the present study, we further reviewed the APLA status and its relation with clinical outcome of this cohort of patients over a further 7 year follow-up period. Out of the initial cohort of 27 patients, follow-up APLA testing was available in 21 patients who were tested for APLA at least once during this time. Seven (33.3 %) of these 21 patients were never positive for any of the APLA; 1 (4.8 %) was persistently positive; and 13 (61.9 %) were positive for APLA intermittently or at least once. Overall, APLA positivity for IgG, IgM anticardiolipin antibodies (ACA) and lupus anticoagulant (LA) was comparable, with positivity seen in 10 (47.6 %), 9 (42.9 %) and 9 (42.9 %) cases, respectively. Anti-ß2 GP1 antibodies were tested in 11 patients on follow-up, of which 3 (27.3 %) showed positivity. In all, 10 (47.6 %) patients showed positivity for more than 1 APLA. Two (9.5 %) patients showed varying degrees of positivity for LA, ACA, and anti-ß2 GP1 antibodies at different times, thereby showing the importance of checking for all APLAs at each time of testing. Out of these 21 patients, 3 (14.3 %) patients had thrombosis, and all 3 patients were positive for APLA. There were 2 (9.5 %) fatalities-both of these had thrombosis and were positive for APLA. Our study shows that pSLE patients on treatment frequently test positive for APLA. Thrombosis was infrequent in this cohort. However, when present it was associated with APLA positivity and high fatality in our experience. On the other hand, presence or persistence of these antibodies was not always associated with thrombosis. Our study suggests that pSLE children should be tested routinely for APLA, as this would identify patients with an increased risk of thrombotic complications. However, the frequency of repeat testing for APLA in those who test negative initially needs to be determined on a case-to-case basis.