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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.

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.

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.

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.

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.

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.

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.

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-β 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.

Fibers are conventionally used as stabilizers in the construction of Stone Matrix Asphalt (SMA) pavements. These fibers are not manufactured in India and are imported from Germany. Naturally occurring jute fibers were coated with low viscosity binder and were used in the present study as an alternative to the patented fibers. Use of crumb rubber modified binder (CRMB) is also investigated as stabilizer in SMA mixes. The performance of these mix were evaluated by conducting draindown by two different methods, moisture susceptibility test, durability test, rutting test and fatigue life tests. German draindown test is not suitable for modified binder. NCAT basket test is better in evaluating mixes prepared with both stabilizers. The results of mix prepared with indigenously available fibers are comparable to the patented fibers. Mix prepared with modified binder alone provides encouraging results.

Quality of bitumen plays a key role in the performance related properties of asphalt mixes. The rapid increase in the number of commercial vehicles combined with overloading of trucks and substantial variation in daily and seasonal temperature of the pavement have been responsible for premature failure of the flexible pavements in India. The bitumen obtained from Indian refineries meets the existing specifications, but the studies have shown that the premature failure of flexible pavements in India is mainly occurring due to inability of conventional asphalt mixes to sustain repeated application of wheel load. The quality of bitumen can be improved by adding additives to the bitumen. This paper presents laboratory investigations on the performance of the styrene butadiene styrene (SBS) and linear low-density polyethylene (LLDPE) modified mixes. The optimization of polymer is normally done on the basis of empirical tests in many countries including India, in this study, the optimum dose of modifier is dete...

Synthetic fibres are conventionally used in the construction of Stone Matrix Asphalt (SMA) in bituminous pavements. The synthetic fibres are not manufactured in India and are imported at a higher cost. As an alternative to synthetic fibre, coated jute fibres were used and its properties were studied. The paper presents details of the laboratory investigations carried out to determine the feasibility of use of natural fibre vis-a-vis synthetic fibre in bituminous gap graded mix. The performance of these mix were evaluated by conducting moisture susceptibility test, rutting test, accumulated strain and creep modulus and stiffness modulus. The test results indicated that the natural jute fibre can replace synthetic fibres in SMA mixture. A slightly higher accumulated strain and subsequently slightly lower creep modulus were observed as compared to SMA with synthetic fibre at 40°C and 50°C temperatures. However, Hamburg wheel test results indicated that permanent deformation is same in both fibres. T...

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), aβ2Gp1 (anti-βeta-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 aβ2Gp1 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. aβ2Gp1, 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 aβ2Gp1 was the most frequent pattern (38% of cases). Conclusions aβ2Gp1 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 aβ2Gp1 antibody had the highest sensitivity and negative predictive value.

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.

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.

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-β2 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-β2 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.

Open-graded friction course (OGFC), which consists of an open gradation mostly of coarse size aggregate with little fines, is a special purpose mixture that is increasingly used in pavement surfacing around the world. The typical benefits of an OGFC mixture are increased surface permeability, noise reduction, and enhanced surface friction, especially in wet conditions. This paper presents results of a study focusing on the use and properties of OGFC mixtures containing reclaimed polyethylene modified binder (RPEB), crumb rubber modified binder (CRMB), and neat 60=70-grade binder with cellulose fibers. The relative performance of mixtures and an aspect relating to the design of such mixtures, based on the laboratory study, have been presented in detail. Several laboratory tests were carried out in this study to evaluate open-graded friction course mixture properties by adopting two different types of Marshall compaction. A draindown test, a Cantabro stone loss test, a permeability test, an indirect tensile strength test, a resilient modulus test, a rutting test, and a skid resistance test were used to evaluate the performance of OGFC mixtures. The addition of fiber stabilizers and polymerized asphalt significantly reduced the potential for draindown in OGFC mixtures. Mixtures compacted by 50 blows on one face by a Marshall hammer were found to give improved results with respect to abrasion and other related mixture properties of the OGFC mixtures. The test results indicated that polymer modi- fication of the binder enhances the relevant engineering properties of the OGFC mixtures. Tensile strength ratio (TSR) values were found to be less for mixtures with modified binders than the mixtures with unmodified binders and fibers. DOI: 10.1061/(ASCE)TE.1943-5436 .0000304. © 2012 American Society of Civil Engineers.