Indrani Roy

Bose Institute, Calcutta, Bengal, India

Are you Indrani Roy?

Claim your profile

Publications (17)28.91 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background. The seasonal pattern of asthma-related hospitalization has often been correlated with ambient allergen/pollutant levels. Objective. To examine the relationship between asthma-related hospital admissions (ARHA) and outdoor pollen, spore, and pollutant levels for adult patients in a densely populated Indian megacity Kolkata. Methods. ARHA data were obtained from two major teaching hospitals of the city. Pollen and spores causing allergic sensitization were identified by skin prick tests (SPTs) among respiratory allergic subjects (N = 1353). Outdoor concentrations of aeroallergens were determined using a Burkard sampler for five consecutive years (2004-2009). Levels of NO(2), SO(2), suspended particulate matters (SPMs), and respirable particulate matters (RPMs) were made available by West Bengal Pollution Control Board (WBPCB, Government of West Bengal). Poisson multivariate Poisson regression (with adjustments for overdispersion) was used to model the data. Results. We found that ARHA in Kolkata increased with predictable regularity in March and September, while remaining low in January and July. SPT showed highly positive skin reactions with grass/weed and palm pollens in respiratory allergic patients, while Aspergilli spores also evoked good sensitivity. In our regression model, the airborne pollen types, Cheno-Amaranthaceae and Cyperaceae, and the inorganic pollutant, SO(2) and RPM, were significantly associated with ARHA (p < .05). Conclusion. ARHA in the megacity of Kolkata shows two seasonal peaks that can be correlated with outdoor grass/weed pollen and RPM concentrations. In contrast, the city's ambient fungal spore counts were not found to be significantly associated.
    Journal of Asthma 10/2012; 49(8):792-9. · 1.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Airborne pollen is an important and potent source of aeroallergens. The aim of the study was to conduct a 2-year aerobiological survey in Calcutta, India, for knowing the concentration and seasonal periodicity of Lantana camara (LC) pollen. The sensitization due to this pollen among seasonal respiratory allergic patients and its chemical composition was studied. An aerobiological survey was conducted with a volumetric Burkard sampler from 2004 to 2006. Protein components of LC pollen were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis and IgE immunoblotting. Allergenic activities were determined by in vivo (skin prick test) and in vitro (enzyme-linked immunosorbent assay. In vitro inhibition tests were performed to evaluate cross-reactivity. LC pollen was present from March to May and from September to December contributing up to 10.5% to the total aeropollen load during peak month. Horizontal profile showed highest concentration for nearest (0.5 m) rotorod and it was decreased by half in a distance within 4.5–6.5 m from plot edge. LC pollen contained 7.5% carbohydrate, 19.3% lipid with proline and valine as dominant amino acid. Among 1,500 adult respiratory allergic patients tested, 7.93% showed higher level of positive reaction. IgE binding proteins of 22, 42, 45 and 95 kD were revealed. LC pollen showed remarkable cross-reactivity with other local Verbenaceae pollen taxa (Clerodendron viscosum, Tectona grandis and Vitex negundo). This is the first study on LC pollen regarding its aerobiological, clinical and immuno-biochemical aspects; it should be helpful for the diagnosis and therapy of patients susceptible to LC pollen.
    Aerobiologia 06/2012; 28(2-2):107-119. · 1.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Peltophorum pterocarpum (yellow gulmohar, PP) pollen is an important aeroallergen for type I hypersensitivity in the tropics. To isolate and characterize the IgE-binding proteins of PP pollen for the first time. Pollen extract was fractionated by a combination of Sephacryl S-200 column and diethylaminoethyl-Sephadex column. Allergen characterization was done by sodium dodecyl sulphate polyacrylamide gel electrophoresis, periodic acid-Schiff staining, enzyme-linked immunosorbent assay, and western blotting. Allergenic activities were determined by in vivo (skin prick test) and in vitro (enzyme-linked immunosorbent assay and histamine release) analyses. To determine whether the carbohydrate chains are involved in immunoreactivity, deglycosylation of PP pollen proteins was performed. SPT results on the respiratory allergic patients of Calcutta showed that 32.77% showed positivity with PP pollen. Eight IgE-reactive protein components were found in crude extract. Optimum IgE-reactive fraction 1 was resolved into five subfractions. The subfraction 1a showed maximum IgE reactivity containing the 28 kDa IgE-reactive component. Periodate oxidation showed that protein component was involved in its IgE binding. Twenty-eight kilodalton IgE reactive protein component was recognized by 75% of PP-sensitive patients in Western blotting. It also induced significant histamine release in sensitive patient sera. The purified 28 kDa protein is a clinically relevant allergen with a potential for diagnosis and therapy of patients susceptible to PP pollen.
    Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 05/2011; 106(5):412-20. · 3.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Airborne pollen is an important and potent source of aeroallergens. The aim of the study was to conduct a 2-year aerobiological survey in Calcutta, India, for knowing the concentration and seasonal periodicity of Lantana camara (LC) pollen. The sensitization due to this pollen among seasonal respiratory allergic patients and its chemical composition was studied. An aerobiological survey was conducted with a volumetric Burkard sampler from 2004 to 2006. Protein components of LC pollen were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis and IgE immunoblotting. Allergenic activities were determined by in vivo (skin prick test) and in vitro (enzyme-linked immunosorbent assay. In vitro inhibition tests were performed to evaluate cross-reactivity. LC pollen was present from March to May and from September to December contributing up to 10.5% to the total aeropollen load during peak month. Horizontal profile showed highest concentration for nearest (0.5 m) rotorod and it was decreased by half in a distance within 4.5–6.5 m from plot edge. LC pollen contained 7.5% carbohydrate, 19.3% lipid with proline and valine as dominant amino acid. Among 1,500 adult respiratory allergic patients tested, 7.93% showed higher level of positive reaction. IgE binding proteins of 22, 42, 45 and 95 kD were revealed. LC pollen showed remarkable cross-reactivity with other local Verbenaceae pollen taxa (Clerodendron viscosum, Tectona grandis and Vitex negundo). This is the first study on LC pollen regarding its aerobiological, clinical and immuno-biochemical aspects; it should be helpful for the diagnosis and therapy of patients susceptible to LC pollen.
    Aerobiologia 01/2011; · 1.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Delonix regia and Peltophorum pterocarpum pollen are important aeroallergens for type 1 hypersensitivity in the tropics. The IgE-binding proteins of D regia and their cross-allergenity with P pterocarpum pollen have not been evaluated. To isolate and characterize the IgE-binding proteins of D regia pollen for the first time and to investigate the cross-allergenity with P pterocarpum pollen belonging to the same family (Leguminosae). Allergenic activities were determined by in vivo and in vitro analyses. Pollen extract was fractionated by a combination of 2 columns (diethyl amino ethyl Sephadex and Sephacryl S-200). Protein components were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, periodic acid-Schiff staining, and immunoblotting. In vitro inhibition tests were performed to evaluate the cross-reactivity. The skin prick test results of the patients with respiratory allergies in Calcutta, India, showed 31.1% positivity with D regia pollen. Nine IgE-reactive protein components were found in the crude extract. An optimum IgE-reactive fraction was resolved into 4 subfractions. Subfraction A, which showed maximum IgE reactivity, contained 2 (96- and 66-kDa) IgE-reactive protein components. The 66-kDa component was found to be glycoprotein. Remarkable cross-reactivity between D regia and P pterocarpum pollen was found on IgE enzyme-linked immunosorbent assay inhibition and dot blotting. Shared IgE-binding components (66, 56, 32, 28, 25, and 23 kDa) were observed between D regia and P pterocarpum pollen extracts, whereas the 96- and 43-kDa components were specific to D regia. The purification of the IgE-binding proteins and the identification of the shared/cross-reactive proteins in these taxonomically related pollen members should be helpful for the diagnosis and therapy of patients susceptible to these pollens.
    Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 12/2009; 103(6):515-24. · 3.45 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Food allergy may be defined as an immunoglobulin E-mediated immune response to food proteins. Such studies have previously not been done in Calcutta, India. The present study was therefore undertaken to record the sensitivity to commonly consumed foods in patients with allergic rhinitis and asthma. Materials and Methods: A survey of 800 patients (410 males and 390 females) reporting to the Allergy Unit of the Institute of Child Health, Calcutta, were selected for the study conducted from May 2006 to April 2007. Respiratory allergic patients in the age group of 5 to 60 years were evaluated using a standard questionnaire, and skin prick test was performed using common food and aeroallergens. Results/Conclusions: Out of the 684 patients with a history of food allergy, most of them, that is, 338, are in the age group 16 to 40 years, 192 of them were in the age group 41 to 60 years, and 154 were in the age group 5 to 15 years. Most of the patients with food allergy had asthma (65.05%), rhinitis and asthma (20.03%), and skin allergies (4.97%), such as itching, eczema, and urticaria. The foodstuffs that were found to elicit symptoms of hypersensitivity were egg, milk, wheat, pulses, vegetables, fishes, and fruits. The patients aged between 16 and 40 years (male-female ratio, 1:1.19) were mostly sensitive to prawn, brinjal, banana, ladyfinger, papaya, wheat, and egg. The age group 41 to 60 years (male-female ratio, 1:1.04) had high skin reactivity to brinjal, egg, banana, fish, and Phaseolus mungo. Patients younger than 16 years (male-female ratio, 1:1.33) were sensitized to brinjal, prawn, banana, spinach, and egg. We observed that food hypersensitivity also reflects different genetic factors and variations in cultural and dietary habits of each individual.
    World Allergy Organization Journal 01/2009; 2:9-12.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Peltophorum pterocarpum and Delonix regia are dominant avenue trees in the city of Kolkata in India. They are well adapted to the humid tropical climate and also grow commonly in different parts of the country. Their pollen grains are reported to be airborne. The aim of this study was to conduct an aerobiological survey in Kolkata to determine the concentration and seasonal periodicity of pollen grains from P pterocarpum and D regia and to analyze the meteorological factors responsible for their levels in the atmosphere. In addition, we analyzed the prevalence of sensitization due to these grains among patients with seasonal respiratory allergy. An aerobiological survey was conducted with a volumetric Burkard sampler from 2004 to 2006. Correlations between meteorological parameters and pollen grain concentrations were assessed by Spearman correlation test. The protein profile of the pollen extracts was studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Finally, the allergenic potential of the pollen extracts was evaluated in patients with respiratory allergy by skin prick test, immunoglobulin (Ig) E enzyme-linked immunosorbent assay, and IgE immunoblotting. P pterocarpum and D regia pollen grains occur from March to June and April to July, respectively. The pollen concentrations showed statistically significant positive correlations with maximum temperature and wind speed. Positive reactions to P pterocarpum and D regia were observed in 26% and 22% of the patients, respectively. Many protein bands were detected in the pollen extracts over a wide molecular weight range. A total of 5 (P pterocarpum pollen) and 8 (D regia pollen) protein fractions were detected by IgE immunoblotting. P pterocarpum and D regia pollen grains are dominant in the atmosphere of south Kolkata and they are influenced by temperature. The pollen grains release proteins that may be responsible for immediate hypersensitivity reactions in sensitive patients.
    Journal of investigational allergology & clinical immunology: official organ of the International Association of Asthmology (INTERASMA) and Sociedad Latinoamericana de Alergia e Inmunología 02/2008; 18(1):22-30. · 1.89 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The role of pollen grains as a causative agent of respiratory allergic disorders such as asthma and allergic rhinitis is common and very well established. The aim of this study was to assess the frequencies of airborne pollen in the Calcutta metropolis and to identify the taxa which cause significant amounts of sensitization. An aeropalynological survey of the atmosphere of Calcutta was carried out from 2004 to 2006. Skin tests were performed with a panel of the most common pollen types on local patients with clinical features of pollinosis. The meteorological factors responsible for the frequency of the pollen types were analysed. The results of monthly visits to the clinic by these patients were correlated with the monthly pollen counts of three dominant and perennial pollen taxa. The dominant pollen types were Trema (19%), Poaceae (12.98%), Casuarina (5.76%), Cocos (5.7%), Azadirachta (4.65%), Peltophorum (3.71%), Cyperaceae (3.68%), Delonix (3.18%) and Areca (2.56%). Total pollen concentration seems to have a significant positive correlation with temperature and wind speed whereas there was a negative correlation with humidity. Skin tests were most frequently found to be positive with the pollen of Poaceae (49%), Azadirachta (46%), Cocos (47%), Cyperaceae (35%), Peltophorum (33%), Areca (29%), Phoenix (26%), and Borassus (23%). A positive correlation occurred between visits to the clinic and monthly pollen count of Areca, Cocos, and Poaceae. This is the first study to design a pollen calendar for Calcutta city; it will provide useful data for enabling allergologists to achieve accurate diagnosis for patients with pollen hypersensitivity.
    Aerobiologia 01/2008; 24:151-164. · 1.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Catharanthus roseus G. Don. (CR) or periwinkle plants are widely grown/ cultivated as garden plants in the tropics and subtropics. In spite of its predominantly entomophilous nature, CR pollen had been reported to be airborne and allergenic. The objective of this study was to discover the seasonal changes of CR pollen concentration in air, to determine its potential to cause respiratory allergy and to analyze its allergenic components. A 2-year aerobiological survey was conducted with a Burkard 7-day sampler in an agricultural farm in the suburban zone of Calcutta city where CR pollen was found to be almost perennial with 3.6-5.4% contribution to the aeropollen load. Skin prick test was conducted on 282 respiratory allergic individuals living within a 15 km radius of the study area. 29.8% of them were positive to CR pollen. Among them, 80.9% were directly involved in gardening. The whole pollen extract was subjected to gel filtration in a Sephacryl S-200 column. Among 5 eluted fractions, fraction I showed optimum IgE-reactivity in ELISA-inhibition. The fraction I shows 4 protein components in SDS-PAGE, within which 3 (40-66 kD molecular mass) were found to be IgE-reactive in immunoblotting using patient sera. It can be concluded that CR pollen can trigger IgEmediated respiratory allergy in the people living in close proximity.
    Annals of agricultural and environmental medicine: AAEM 02/2007; 14(1):39-43. · 3.06 Impact Factor
  • World Allergy Organization Journal. 01/2007;
  • World Allergy Organization Journal. 01/2007;
  • World Allergy Organization Journal. 01/2007;
  • World Allergy Organization Journal. 01/2007;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although the efficacy of allergen immunotherapy has been demonstrated in seasonal pollen allergy, there is no report of a double-blind placebo-controlled trial with standardized pollen extract in seasonal respiratory allergy from India. In the agricultural area of eastern India, Phoenix sylvestris Roxb or date sugar palm is grown or cultivated and seasonal allergic rhinitis is common during the pollen season. The objective of the present study was to observe the clinical and immunological changes during a 2-year double-blind placebo-controlled trial of immunotherapy with standardized P sylvestris pollen extract in respiratory patients sensitive to pollen from this wild date palm. Thirty-five subjects with typical seasonal allergic rhinitis with or without bronchial asthma were selected. A symptom-medication score (based on a questionnaire and diary) was correlated with pollen counts as recorded in a Burkard sampler. Eighteen subjects were randomized to a specific immunotherapy (SIT) group receiving regular injections containing standardized allergen extract and 17 to a placebo control group. Changes in the level of specific immunoglobulin (Ig) E, IgG1, and IgG4 were recorded at 3-month intervals. Measurement of wheal diameter, total IgE level and forced expiratory volume in 1 second (FEV1) were performed before starting and a month after finishing therapy. The SIT group showed decreases of 33.5% and 57% from the baseline symptom-medication scores during the first and second treatment season, respectively. This group showed significant decreases in skin-reactivity to P sylvestris pollen extract and in specific IgE levels, and significant increases in FEV,, specific IgGI (1.95-3.2 times higher) and IgG4 (21.24-30.83 times higher). There were no significant changes in total IgE levels. The control group showed no significant changes for any parameter except the development of new sensitization in 2 cases (to Saccharum officinarum pollen grain and Alternaria species spores). The rate of local adverse reactions was 0.024%. After a 2-year study, allergen immunotherapy with standardized P sylvestris pollen extract was found to be effective in seasonal respiratory allergic subjects susceptible to P sylvestris pollen with a narrow range of sensitization.
    Journal of investigational allergology & clinical immunology: official organ of the International Association of Asthmology (INTERASMA) and Sociedad Latinoamericana de Alergia e Inmunología 02/2006; 16(6):377-84. · 1.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Carica papaya L. is a fruit yielding tree, wildly grown or cultivated in the tropics and subtropics. Its pollen grain has been reported to be airborne and cause immunoglobulin E (IgE)-mediated hypersensitivity. To conduct long-term aerobiological study on Carica pollen, along with aeroallergenic particles originating from it and to identify vis-a-vis characterize an important IgE-reactive component present in this pollen. The seasonal and diurnal periodicities of airborne C. papaya pollen were recorded in a 5-year survey using a Burkard volumetric sampler. The allergenic potential was studied by skin prick tests, IgE-enzyme-linked immunosorbent assay (ELISA) and also by aeroallergen immunoblotting. The total pollen extract was fractionated by Sephacryl S-200 column, and out of the eluted five fractions, the maximum IgE-reactive fraction (as found in ELISA inhibition) was resolved into five major subfractions in reverse-phase high-performance liquid chromatography (RP-HPLC). The subfraction with optimum IgE reactivity was studied by activity gel, native and nonreducing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The homogeneity of the isolated protein fraction was checked by crossed immunoelectrophoresis with rabbit antisera and IgE reactivity was confirmed by ELISA inhibition and immunoblotting using individual patient sera. The Carica pollen occurred in the air round the year with peaks during January and September-October. Among a patient population of 1000, skin-test results showed 27.8% +1 level and 5.6% +2/+3 level reactions. In aeroallergen immunoblotting of exposed Burkard tape segments, the detected allergen spots showed a significant correlation with airborne pollen count recorded. The pollen extract elicited loss of IgE reactivity when treated with reducing agent-like beta-mercaptoethanol and heat, but showed six IgE-reactive components in nonreducing IgE-immunoblot. The fraction 1 eluted from Sephacryl S-200 column showed highest IgE reactivity and resolved into five major components in RP-HPLC. Out of these, the fraction showing optimum IgE reactivity in IgE-ELISA inhibition and immunoblotting with patient antisera, elicited esterase activity and found to be a homogenous protein of 100 kDa. Carica papaya tree contributes significantly to the aeropollen and aeroallergen load of the suburban outskirts of Calcutta metropolis, India. The pollen extract contains an important IgE-reactive protein component of 100 kDa molecular weight with esterase activity.
    Allergy 08/2005; 60(7):920-6. · 5.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Arecaceae (palm) family is predominantly distri- buted in the tropics and subtropics. Areca catechu (be- tel nut), Borassus flabellifer (fan palm), Cocos nucifera (coconut) and Phoenix sylvestris (date sugar palm) are widely cultivated all over the Indian subcontinent. These members are anemophilous and release numer- ous pollen grains in air during pollination period. These grains are known to cause IgE-mediated human respiratory allergy. In this context, a study was co n- ducted on 448 respiratory allergic subjects, sensitive to one/more of the relevant pollen types from Greater Kolkata and suburbs, by case study, skin reaction test, IgE-ELISA, immunoblot and immunoblot inhibition. 72 and 48 kDa components from Areca, 100 kDa com- ponent from Borassus, 16 kDa component from Cocos and 66 and 33 kDa components from Phoenix pollen were found to be inhibited by the other three respe c- tive pollen extracts. This may be due to the sequence and structural homology of the epitopes. Therapeutic and diagnostic use of these shared components carry- ing most of the IgE-epitopes could minimize the haz- ards of impurities and side effects in allergen -specific immunotherapy/hypo-sensitization of palm pollen sus- ceptible allergic patients. THE Arecaceae (palm) comprises about 217 genera and 2500 species, distributed mainly in the tropics and su b- tropics. This family contains a number of economically important members, among which some of the most impor- tant ones include Cocos nucifera L. (coconut), Borassus flabellifer L. (palmyra/fan palm), Areca catechu L. (betel nut) and Phoenix sylvestris Roxb. (wild date/date sugar palm) growing/cultivated in a large scale in the Indian sub - continent1. These perennial woody trees are wind-pollina- ted and release a huge number of pollen in the air 2 during flowering period. On i nhalation, airborne pollen grains release soluble proteins, which are the trigger of IgE - mediated type 1 allergic symptoms like rhinitis and bro n- chial asthma3. In India, around 10% of people suffer from different kinds of respiratory alle rgic disorders4. P revious reports revealed that palm pollen grains as allergenically highly potent2,5, share antigenic components6 and show
    01/2004;
  • [Show abstract] [Hide abstract]
    ABSTRACT: The pollen grains of Arecaceae have been proved to be a very common aeroallergen in India. Except for the pollen grains of Cocos nucifera, detailed information about the allergenicity of other dominant Indian palm pollen is not available. To explore the aerobiologic and allergenic significance of the pollen of palmyra palm (Borassus flabellifer Linn.), one of the important and common palm trees in India, with a view to isolate and purify its major allergenic components. The aerobiologic survey was performed continuously using Burkard volumetric and Rotorod samplers from July, 1994 to June, 1996 in a northern suburb of greater Calcutta. The allergenic potential of the pollen extract and different fractions were studied by skin prick tests (SPT). ELISA and ELISA inhibition experiments were performed with individual and pooled patient sera to detect the specific IgE level. By 2-step ammonium sulphate fractionation and gel filtration study, the allergic fraction Fr.IIA1 was isolated. Its molecular weight was determined by SDS-PAGE and homogeneity was confirmed by rocket and crossed immunoelectrophoresis using rabbit antisera. Pollen grains of B. flabellifer were found to be present in air from February to May and June contributing more than 7% of the total airborne pollen load of the study area. The pollen elicited maximum concentration at 19 to 20 hours in the evening and at a height of 4 m from ground level. Skin prick testing of 455 respiratory allergic patients with whole pollen extract exhibited 31.64% positive response. After 2-step ammonium sulphate fraction and gel filtration, a fraction (Fr.IIA1) having remarkable allergenicity was isolated. In native and SDS-PAGE, it was found as a single protein component of 90 kD and as homogeneous in RIE and CIE. The soluble protein-carbohydrate analysis indicated the probability of the component to be a glycoprotein. The aerobiologic, clinical, and immunochemical, studies demonstrated that the pollen of B. flabellifer is a dominant aeroallergen to cause respiratory trouble in the area where these trees grow. The isolated 90-kD component is one of the major allergens present in the pollen extract.
    Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 05/1998; 80(4):311-7. · 3.45 Impact Factor