Humoral immune response and changes in peritoneal cell populations in rats immunized against two Leptospira serovars; serovar patoc and serovar pyrogenes.

BACKGROUND: Leptospirosis is a zoonotic disease caused by Leptospira species. Variations in lipopolysaccharide (LPS) structure in Leptospira are known to be associated with the serovar diversity and antigenicity. Development of immunodiagnostics for early detection of leptospirosis based on immune responses against different pathogenic antigens as well as development of vaccines are important. Hence, this study has assessed the immune response generated against leptospiral LPS and whole antigen preparations of pathogenic and saprophytic Leptospira and specific changes in peritoneal cells was also studied to elucidate the cellular responses associated with immune response of Wistar rats. METHODS: During the study, immune response induced by two types of Leptospira antigen preparations of two selected serovars was compared. Changes in the specific peritoneal cell subpopulations following immunizations of rats were analyzed using flow cytometry. RESULTS: Of the two antigen preparations tested, the LPS extract induced a higher IgM immune response as opposed to the sonicated antigen preparation. Of the two serovars tested, L. interrogans serovar Pyrogenes had induced a higher IgM response compared to that by L. biflexa serovar Patoc. Considering the IgG titers, equivalent responses were observed with all four antigen preparations. Significant increases in lymphocytes were observed following immunization with LPS of both serovars. Interestingly, the B2 cell percentages increased significantly during the immunization period. Further, significant correlations were observed with both IgM and IgG responses and percentage of B2 cells in the peritoneal cavity (PC). CONCLUSION: LPS extract of L. interrogans serovar Pyrogenes induced higher IgM response while the IgG response was equivalent among the four antigen preparations tested. Significant increase of B2 cell percentage in the peritoneal cavity during the immunization reflects the accumulation of B2 cells in the PC which may play considerable role in generating humoral response against Leptospira antigens.

Inborn Errors of Immunity-the Sri Lankan Experience 2010-2022.

PURPOSE: Inborn errors of immunity (IEI) are typically monogenic. Data from the Indian subcontinent are relatively scarce. This paper evaluates IEI diagnosed in Sri Lanka. METHODS: Data of patients diagnosed with IEI from 2010 to 2022 at the Department of Immunology, Medical Research Institute, Colombo, Sri Lanka, were retrospectively analyzed. RESULTS: Two hundred and six patients were diagnosed with IEI, with a prevalence of 0.94 per 100,000. The onset of disease was below 12 years in 84.9%, whereas in 10.9%, it was after 18 years. The male: female ratio was 1.78:1. Consanguinity was identified in 26.6%. IEI were found in all but one (bone marrow failure) of the 10 IUIS categories. Predominantly antibody deficiencies were the most common category among the nine identified (30.1%), followed by combined immune deficiencies with syndromic features (21.3%), immunodeficiencies affecting cellular and humoral immunity (19.9%), congenital defects of phagocyte number or function (13.1%), and defects in intrinsic and innate immunity (8.2%). Severe combined immune deficiency (SCID) was the commonest disease (14.6%), followed by chronic granulomatous disease (CGD) (10.6%) and X linked agammaglobulinemia (8.7%). Of the patients with a known outcome (n = 184), 51 died (27.7%). Mortality rates were high in SCID (83.3%), Omenn syndrome (OS) (100%), and CGD (31.8%) patients. CONCLUSION: IEI in Sri Lanka are diagnosed mainly in childhood. The low diagnosis rates suggest a need for educating clinicians regarding IEI in adulthood. The high mortality rates associated with some IEI indicate the need of transplant services in the country.

Identification of allergens in Artocarpus heterophyllus, Moringa oleifera, Trianthema portulacastrum and Syzygium samarangense.

BACKGROUND: It is clinically important to identify allergens in Artocarpus heterophyllus (jackfruit), Moringa oleifera (moringa), Trianthema portulacastrum (horse purslane) and Syzygium samarangense (rose apple). This study included 7 patients who developed anaphylaxis to jackfruit (1), moringa (2), horse purslane (3) and rose apple (1). We sought to determine allergens in the edible ripening stages of jackfruit (tender, mature, and ripened jackfruit) and seeds, edible parts of moringa (seeds, seedpod, flesh inside seedpod, and leaves), horse purslane leaves and ripened rose apple fruit. The persistence of the allergens after cooking was also investigated. METHODS: Allergens were identified by clinical history followed by a skin prick test. Protein profiles of plant/fruit crude protein extracts were determined by SDS-PAGE. Molecular weights of the allergens were determined by immunoblotting with patient sera. RESULTS: A heat-stable allergen of 114 kDa in A. heterophyllus which is shared among different ripening stages and seeds was identified. Additionally, 101 kDa allergen in boiled tender jackfruit, 86 kDa allergen in boiled seeds and 80 kDa allergen in boiled mature jackfruit were identified. Five heat-stable allergens of 14, 23, 35, 43, and 48 kDa in M. oleifera, 1 heat-stable allergen of 97 kDa in T. portulacastrum, and 4 allergens of 26, 31. 60, and 82 kDa in S. samarangense were identified. CONCLUSION: Novel IgE-sensitive proteins of A. heterophyllus, M. oleifera, T. portulacastrum and S. samarangense were identified which would be especially useful in the diagnosis of food allergies. The identified allergens can be used in Component Resolved Diagnostics (CRD).

Identification of allergens in coconut milk and oil with patients sensitized to coconut milk in Sri Lanka.

BACKGROUND: Despite the low prevalence of IgE sensitivity to fresh or boiled coconut milk and coconut oil, those may contain allergens of which the clinical significance remains undetermined. This study aimed to identify and compare allergens in fresh coconut milk (FCM), boiled coconut milk (BCM), unrefined wet-processed coconut oil (WPCO), and dry-processed coconut oil (DPCO) using sera from patients with allergy to coconut milk. METHODS: The study included 18 patients with immediate hypersensitivity to coconut milk, including five who developed anaphylaxis. Sensitization was assessed by skin prick test and ImmunoCAPs using commercially available coconut extracts. Immunoblotting was performed to identify and compare allergen profiles. RESULTS: Total sIgE levels and overall IgE reactivity of patients with anaphylaxis were higher compared to patients with allergy. Twelve allergens ranging from 5 to 128 kDa including six novel allergens with 5, 12, 47, 87, 110, and 128 kDa were visualized in immunoblots with FCM. Similarly, nine allergens of 5, 12, 17, 32, 35, 47, 87, 110, and 128 kDa were detected in BCM. One allergen (110 kDa) was discerned in all four extracts. Higher IgE prevalence was detected with three allergens of 55, 87, and 110 kDa. CONCLUSIONS: Allergens of BCM and unrefined coconut oil (WPCO and DPCO) were determined for the first time. Novel allergens of 87 and 110 kDa and the 55 kDa allergen have the highest potential to be used in Component Resolved Diagnostics. Further, these findings demonstrate that, patients who have an allergy to coconut milk could also react to boiled coconut milk and unrefined coconut oil.

Diagnosis of Apis dorsata venom allergy: use of recombinant allergens of Apis mellifera and a passive basophil activation test.

BACKGROUND: Allergy to Apis dorsata (Giant Asian Honeybee) venom is the commonest insect allergy in Sri Lanka and South East Asia. However, laboratory diagnosis is difficult as the pure venom and diagnostic reagents are not commercially available. OBJECTIVE: This study assessed the use of four recombinant allergens of A. mellifera venom and the passive basophil activation test in the diagnosis of A. dorsata venom anaphylaxis. METHODS: Serum IgE levels to four recombinant allergens of A. mellifera, rApi m 1, 2, 5 and 10 were assessed and compared with serum IgE to the crude venom of A. mellifera or V. vulgaris by Phadia ImmunoCAP, in patients who developed anaphylaxis to A. dorsata stings. Basophil activation in response to venom of A. dorsata or V. affinis was assessed using a passive basophil activation test. Association of the severity of the reaction with basophil activation was compared. RESULTS: rApi m 1 and 10 combinedly had significant correlation (r = 0.722; p < 0.001) with the crude venom of A. mellifera (Western honeybee) and a higher positivity rate of 90% (27/30). Whereas, IgE reactivity to rApi m 2 or 5 had significant correlation (p = 0.02 and p = 0.005 respectively) with V. vulgaris crude venom. All 30 (100%) were positive to A. dorsata venom in passive BAT; 70% (21/30) had over 80% activation, 96.7% (29/30) had over 60% activation and 100% had over 50% activation. Percentage activation of basophils in patients who had mild or moderate reactions (n = 20) was significantly low (p = 0.02) from that of patients who had severe reactions (n = 10). CONCLUSIONS: rApi m 1 and 10 when combined was sensitive for the diagnosis of A. dorsata allergy. This combination had the lowest cross-reactivity rate with Vespula vulgaris. The passive BAT is highly sensitive in A. dorsata allergy. The basophil reactivity was significantly higher in severe anaphylaxis compared to mild/moderate anaphylaxis. This finding should be further explored in further studies.

Autoimmune encephalitis in a South Asian population.

BACKGROUND: Autoimmune encephalitis (AE) is now considered a main, potentially curable cause of encephalitis, but remains conspicuously underreported from South Asia. We studied the clinical characteristics in relation to their antibody status and outcomes of patients presenting with AE in Sri Lanka. METHODS: Patients admitting to government hospitals who were clinically suspected of AE by an on-site neurologist were prospectively recruited over a period of 12 months. Sera and cerebrospinal fluid were tested for NMDAR, AMPAR1, AMPAR2, LGI1, CASPR2, GABARB1/B2 antibodies (Ab) using commercial cell-based assays. Demographic, clinical and laboratory data were compiled into an investigator-administered proforma. Patients were reviewed at 1 year follow up either in person or via telephone. RESULTS: One-hundred and forty-two patients from 21 of 25 districts in Sri Lanka (median age = 20.5 years; range 1-86 years; females = 61.3%) were recruited. Of them, 65 (45.8%; median age = 19 years; range 1-86 years; females = 64.6%) fulfilled diagnostic criteria for probable NMDAR-antibody encephalitis (NMDARE) and 6 (4.2%; median age = 44 years; range 28-71 years; females = 83.3%) limbic encephalitis (LE). Abnormal behaviour (95.3%), seizures (81.5%) and movement disorders (69.2%) were the most frequent clinical manifestations of probable NMDARE. NMDAR-antibodies were detectable in 29 (44.6%) and not detectable in 36 in CSF of probable-NMDARE patients. Abnormal EEG was more frequent (p = 0.003) while a worse outcome (OR = 2.78; 95% CI = 0.88-9.09) and deaths (OR = 2.38; 95% CI = 0.67-8.33) were more likely in antibody-negative than antibody-positive probable-NMDARE. Most patients with LE had amnesia (50%) and/or confusion (100%) with agitation (83.3%) and seizures (100%) but none had detectable antibodies to any of the antigens tested. CONCLUSIONS: NMDARE is the commonest type of AE among South Asians as is the case worldwide. Clinical presentations of NMDARAb-positive and NMDARAb-negative AE patients do not significantly differ but EEG may be a useful marker of an autoimmune basis for psychiatric symptoms.

Effect of Antimicrobial Agents on Inflammatory Cytokines in Acute Leptospirosis.

The aim of this study was to assess the inflammatory cytokine response and possible association with antimicrobial treatment with penicillin, ceftriaxone, and doxycycline in acute leptospirosis. In the early acute stage, interleukin-10 (IL-10) levels were higher in mild cases than in severe cases (P = 0.01). IL-6 and IL-8 levels were low in patients who received >5 antimicrobial doses (P < 0.01). IL-8 levels were negatively correlated with the number of ceftriaxone doses administered (r = -0.315; P = 0.031). Further studies are needed to evaluate the possible downregulation of proinflammatory cytokines by ceftriaxone in leptospirosis.

Leflunomide is equally efficacious and safe compared to low dose rituximab in refractory rheumatoid arthritis given in combination with methotrexate: results from a randomized double blind controlled clinical trial.

BACKGROUND: The standard dose of rituximab used in rheumatoid arthritis (RA) is 1000 mg but recent studies have shown that low dose (500 mg) is also effective. Efficacy of low dose rituximab in rheumatoid arthritis (RA) refractory to first-line non-biologic Disease Modifying Anti Rheumatic Drugs (DMARDs), compared to leflunomide is unknown. In a tertiary care referral setting, we conducted a randomized, double blind controlled clinical trial comparing the efficacy and safety of low-dose rituximab-methotrexate combination with leflunomide-methotrexate combination. METHODS: Patients on methotrexate (10-20 mg/week) with a Disease Activity Score (DAS) > 3.2 were randomly assigned to rituximab (500 mg on days 1 and 15) or leflunomide (10-20 mg/day). The primary end-point was ACR20 at 24 weeks. Sample of 40 had 70% power to detect a 30% difference. ACR50, ACR70, DAS, EULAR good response, CD3 + (T cell), CD19 + (B cell) and CD19 + CD27+ (memory B cell) counts, tetanus and pneumococcal antibody levels were secondary end points. RESULTS: Baseline characteristics were comparable in the two groups. At week 24, ACR20 was 85% vs 84% (p = 0.93), ACR50 was 60% vs. 64% (p = 0.79) and ACR70 was 35% vs 32% (P = 0.84), in rituximab and in leflunomide groups respectively. Serious adverse events were similar. With rituximab there was significant reduction in B cells (p < 0.001), memory B cells (p < 0.001) and pneumococcal antibody levels (P < 0.05) without significant changes in T cells (p = 0.835) and tetanus antibody levels (p = 0.424) at 24 weeks. With leflunomide, significant reduction in memory B cells (p < 0.01) and pneumococcal antibody levels (p < 0.01) occurred without significant changes in B cells (P > 0.05), T cells (P > 0.05) or tetanus antibody levels (P > 0.05). CONCLUSIONS: Leflunomide-methotrexate combination is as efficacious as low-dose rituximab-methotrexate combination at 24 weeks, in RA patient's refractory to initial DMARDs. The high responses seen in both groups have favorable cost implications for patients in developing countries. Changes in immune parameters with leflunomide are novel and need further characterization. TRIAL REGISTRATION: The trial was registered with the Sri Lanka Clinical Trials Registry (SLCTR), a publicly accessible primary registry linked to the registry network of the International Clinical Trials Registry Platform of the WHO (WHO-ICTRP) (registration number: SLCTR/2008/008 dated 16th May 2008).

Development and Evaluation of In-House ELISAs for the Detection of SARS-CoV-2-Specific Antibodies in COVID-19 Patients in Sri Lanka.

COVID-19 serological tests complement the molecular diagnostics and can be used as important tool for serosurveillance and vaccine efficiency evaluation. The aim of this study was to develop and evaluate the diagnostic performance of an in-house ELISA for retrospective serosurveillance of SARS-CoV-2. Total IgG and IgM levels in sera of PCR positive SARS-CoV-2 patients (n = 50) from North Colombo Teaching Hospital were evaluated and compared with sera (n = 50) collected from prepandemic healthy individuals as controls. Patient sample collection was initiated before vaccination programme was widely started within the country. Seropositivity of 94.0% (n = 47/50) was observed for either IgG or IgM anti-SARS-CoV-2 antibodies against receptor binding domain of spike protein or nucleocapsid protein in confirmed cases while none of controls were seropositive. In contrast, the seropositivity of only 48.0% (n = 24/50) was demonstrated with commercial ELISA kits for detection of IgG or IgM. All samples detected seropositive by commercially available kits remained seropositive with either in-house IgM or IgG ELISA. Significant correlations (p ≤ 0.001) were observed between Ab levels and day of sampling from the onset of illness. The overall sensitivity values of the in-house assays were 66.7%, 96.9%, and 100.0% for the first, second, and third week or longer after onset of symptoms for either in-house IgM or IgG ELISAs. Majority of the patients (>80.0%) were seropositive, regardless of age (<60 vs. >60 years), gender (male vs. female), or clinical severity (mild vs. moderate/severe). These data suggest that the developed in-house ELISAs can be applied to assess anti-SARS-CoV-2 antibody levels induced by either natural infections or vaccination.

Cardioprotective Effects of Vitex negundo: A Review of Bioactive Extracts and Compounds.

There has been accumulating interest in the application of medicinal plants as alternative medicine to treat various diseases and/or to develop modern medicines. Vitex negundo is one of such medicinal plants that has been of interest to many researchers and has been of use in traditional medicine. V. negundo is found in Sri Lanka, Madagascar, Malaysia, India, China, The Philippines and East Africa. Therapeutic properties of V. negundo have previously been reviewed. Different parts, preparations and bioactive components of V. negundo possess potential protective and therapeutic effects against cardiovascular disease and related conditions as demonstrated in previous studies. We review the present state of scientific knowledge on the potential use of V. negundo and some of its bioactive components in protecting against cardiovascular diseases and related pathologies. Previous studies in animal and non-animal experimental models, although limited in number and vary in design, seem to support the cardioprotective effect of V. negundo and some of its active components. However, there is need for further preclinical and clinical studies to validate the use of V. negundo and its active constituents in protection and treatment of cardiovascular diseases. Additionally, since only a few V. negundo compounds have been evaluated, specific cardioprotective effects or mechanisms and possible side effects of other V. negundo compounds need to be extensively evaluated.

ASVAC2022 : 8th Asian Vaccine Conference.

Aiming to further the Immunization Partners in Asia Pacific (IPAP)'s vision of a world where no one suffers from a vaccine preventable disease, the 8th Asian Vaccine Conference (ASVAC 2022) was held in Colombo, Sri Lanka and virtually from 15 to 18, September 2022 (www.asianvaccine.com). This conference followed those held in Siem Reap, Cambodia (2009), Manila, Philippines (2010), Jakarta, Indonesia (2011), Cebu, Philippines (2013), Hanoi, Vietnam (2015), Singapore (2017) and Naypyidaw and Yangon, Myanmar (2019). The ASVAC2022 themed "Immunization: in Era of Pandemics," commenced with the EPI Managers' Workshop, followed by pre-conference workshops and Vaccinology Masterclass, followed by the main conference featuring 5 plenary lectures, 6 partner-led symposia, free paper and poster presentations, and industry-supported lunch and evening sessions. There were over 1830 registered participants, with 112 attending in person and 998 virtually from 63 countries. The conference was organized by IPAP and hosted by the Vaccine and Infectious Disease Forum of Sri Lanka, Sri Lanka College of Pediatricians, Sri Lanka College of Microbiologists and College of General Practitioners of Sri Lanka, with the support of the Ministry of Health, Sri Lanka. The 9th ASVAC is scheduled to be held in Davao City, Philippines in late 2023.

Food allergy in Sri Lanka - A comparative study.

Background: The incidence of IgE mediated food allergy (FA) is increasing in the west. Cow's milk (CM), hen's egg, wheat, soy, peanut, tree nut, fish, and shellfish are responsible for 90% of food allergy in the west; however, local dietary habits may result in specific allergies. Data on food allergies in South Asia is scarce. The present study aims to evaluate the foods that cause immediate type hypersensitivity in Sri Lanka, and to compare with Asia and the developed west. Methods: Records of patients referred to an Immunology clinic from 2010-January 2022 were reviewed. The diagnosis of food allergy was based on standard guidelines. Confirmation of the specific food implicated was based on the history and the presence of specific IgE or component resolved diagnostics by in vitro methods (Phadia ImmunoCap) or by skin prick testing with commercial extracts (Alk Abello). Prick to prick testing was performed for fruits and vegetables when commercial extracts were unavailable. Results: Three hundred and forty-six patients were confirmed with food allergy. CM allergy (CMA) was the commonest (31.2%) followed by red meat allergy (27.7%) and food dependent exercise induced anaphylaxis (FDEIA) (17.9%). Allergy to alpha-gal crustaceans, eggs, gelatin, wheat, coconut milk, and mollusks were seen in 2-10% of patients.The onset of CMA was mainly in childhood. However, in 23/108 patients, onset was after 5 years, including 8 patients in adulthood, and in 14 of the 23, it was preceded by red meat allergy. Onset of primary red meat allergy was predominantly in children, but in 33/96 (34.3%) of patients, it was in adults. Most patients with alpha-gal allergy (21/29, 72.4%) had initial symptoms in childhood and adolescence.Anaphylaxis was diagnosed in 213 patients. FDEIA is the commonest cause (24.7%) followed by red meat allergy (23%), CMA (21.5%) and alpha-gal allergy (10.3%). Allergy to peanuts and fruits were rare.Patients with red meat allergy and/or CMA developed allergy, including anaphylaxis, to vaccines containing bovine/porcine products. Conclusion: CM was the most common food allergy in children, but egg allergy was uncommon. Primary red meat allergy was the second most common, and was associated with allergy to vaccines containing bovine products, such as the measles, mumps and rubella (MMR) vaccine. Allergy to peanuts and fruits were rare. Primary red meat allergy may be responsible for late onset CMA.

Thymoma complicated with myasthenia gravis and Good syndrome - a therapeutic conundrum: a case report.

BACKGROUND: Thymomas are known to be associated with myasthenia gravis and Good syndrome. Good syndrome is the association of thymoma with combined B cell and T cell immunodeficiency. The combination of all three diseases has not been reported. We discuss the therapeutic dilemma of immunosuppression in such a case. CASE PRESENTATION: A 27-year-old Sinhalese man was evaluated for persistent cough which was associated with pleuritic chest pain and was found to have pleural-based lesions in his left hemithorax. Further evaluation confirmed these lesions to be implants from a thymoma. He subsequently developed myasthenia gravis and impending myasthenic crisis precipitated by pneumonia. He was found to have hypogammaglobulinemia with low B cell counts, confirming a diagnosis of Good syndrome. Treatment with intravenously administered broad-spectrum antibiotics, acetylcholinesterase inhibitors, orally administered glucocorticoids, plasma exchange, and intravenous immunoglobulin led to clinical improvement. He subsequently underwent thymectomy and debulking of the tumor and was maintained on regular intravenous immunoglobulins combined with low-dose prednisolone. CONCLUSIONS: Regular intravenous immunoglobulins combined with low-dose immunosuppression in addition to thymectomy appear to be safe when myasthenia gravis occurs in association with Good syndrome.

Diagnosis of Vespa affinis venom allergy: use of immunochemical methods and a passive basophil activation test.

BACKGROUND: Allergy to Vespa affinis venom is common in the Asia Pacific region. Venom preparations for diagnosis are not commercially available for this species. METHODS: The prominent allergens in V. affinis venom were identifiedusing immunochemical methods. Use of ImmunoCAP of Vespula vulgaris crude venom/its components and a passive basophil activation test (BAT) in the diagnosis of patients who had anaphylaxis to V. affinis venom (n = 30) were also accessed. The IgE double-positivity rates (positive to both hornet and honeybee) in ImmunoCAP and the passive BAT were determined. RESULTS: High IgE reactivity was seen with the five allergens in V. affinis venom; 96% (29/30) for 34 and 24 kDa, 93% (28/30) for 45 kDa and 90% (27/30) reactivity for the 100 and 80 kDa respectively. IgE cross-reactivity was low with ImmunoCAP using V. vulgaris venom (43%; 13/30) and Ves v1 (3%; 1/30), but relatively high with Ves v5 (73%; 22/30). All patients (100%) were positive to V. affinis venom in passive BAT. In ImmunoCAP, a high double-positivity rate (76%; 23/30) was detected while no double-positivity was detected in passive BAT. CONCLUSIONS: High IgE reactivity for five allergens of V. affinis points to the potential of using these allergens in component resolved diagnosis (CRD). The passive BAT has shown its importance as a promising diagnostic tool with high accuracy. It would be particularly useful in cases with doubtful double-positive results of other diagnostic tests.

Hyper IgE recurrent infection syndrome in South Asia: is there a different outcome?

BACKGROUND: Hyper IgE recurrent infection syndrome (HIES) is a rare immune deficiency, characterized by recurrent staphylococcal skin and lung abscesses, pneumonia and increased IgE levels. The majority of autosomal dominant HIES (AD HIGE) is due to hypomorphic mutations in the signal transducer and the activator of transcription 3 (STAT3) gene. CASE PRESENTATION: Five patients were diagnosed with HIES, based on the clinical criteria and scoring system developed at the National Institutes of Health (NIH), USA. The STAT3 gene was sequenced and previously described mutations were identified in all five patients. We compare the clinical features of our patients with those from Asia, Europe and the US. CONCLUSION: Even though the number of patients is limited, there are some clinical differences in patients from South Asia compared to European and even East Asian patients. However, the mutations detected are located at hot spots seen in western and Asian patients with AD HIGE.

Primary immune deficiency among patients with recurrent infections.

OBJECTIVES: Primary immune deficiency is relatively rare. Patients present with recurrent or persistent infections or infections with opportunistic pathogens. We investigated patients who presented during the years 2005-7 with recurrent or persistent infections or infections with opportunistic organisms, for underlying immune deficiency. DESIGN: Descriptive study. SETTING: Department of Immunology, Medical Research Institute, Colombo. STUDY POPULATION: 257 patients referred to the Department of Immunology, Medical Research Institute, Colombo, with a history of recurrent infections, for evaluation of possible immune deficiency. MEASUREMENTS: Appropriate evaluation of immunological competence of the humoral and cell mediated immune systems. RESULTS: There were 8 patients with agammaglobulinaemia (X linked agammaglobulinaemia and autosomal recessive agammaglobulinaemia), 2 patients each with ataxia telangiectasia, IgA deficiency and hyper-IgE syndrome, 3 patients with common variable immune deficiency (CVID), and 1 patient each with Griscelli syndrome, hyper-IgM syndrome and X linked severe combined immune deficiency (SCID). CONCLUSIONS: Primary immune deficiency must be included in the evaluation of patients with recurrent infections, and timely intervention can prevent morbidity and mortality.

Sensitization to bovine serum albumin as a possible cause of allergic reactions to vaccines.

BACKGROUND: Immediate type hypersensitivity to vaccines containing bovine/porcine excipients, such as the measles, mumps and rubella (MMR) vaccine is probably due to sensitization to bovine/porcine gelatin. Most patients with such reactions in Sri Lanka have cow's milk (CM) or beef allergy. OBJECTIVES: We investigated whether those who had beef and CM allergy had a higher incidence of hypersensitivity reactions to vaccines and the possible trigger of such reactions. MATERIAL AND METHODS: Twenty patients with immediate type hypersensitivity reactions to vaccines containing bovine/porcine excipients, controls with allergy to beef/pork (n=11) or CM (n=11), and 8 non atopic controls were recruited. Total serum IgE, specific IgE to beef, CM, casein, beta lactoglobulin, gelatin and bovine serum albumin (BSA) by Phadia ImmunoCap and IgE to porcine gelatin by Western blot were evaluated. RESULTS: 11/20, 5/20, 2/20, 2/20, 1/20 and 1/20 patients reported allergic reactions to measles containing, JE, rabies primary chick embryo, pentavalent, diphtheria and tetanus, and adult diphtheria and tetanus vaccines, respectively. Only one patient with allergy to vaccines had gelatin specific IgE, whereas IgE to BSA was seen in 73.3%, 90%, 66.6% and 0 of vaccine, beef or CM allergic and non-atopic controls, respectively. The mean IgE to BSA was higher in patients with allergy to vaccines, although not significant. Specific IgE to BSA was present in 54.7% of children with allergy to CM, of whom 11.8% had high levels (>17.5kUA/L). In contrast, 66.6% of these children did not have specific IgE to ß-lactoglobulin, which is one of the major components of whey protein. CONCLUSION AND CLINICAL RELEVANCE: Gelatin does not appear to play a major role in Sri Lankan children with allergy to vaccines. In contrast, due to the higher levels of BSA specific IgE, sensitization to BSA is possibly playing a role.

IgE cross-reactivity of phospholipase A2 and hyaluronidase of Apis dorsata (Giant Asian Honeybee) and Apis mellifera (Western Honeybee) venom: Possible use of A. mellifera venom for diagnosis of patients allergic to A. dorsata venom.

Diagnostic and therapeutic reagents are unavailable for anaphylaxis arising from stings by Apis dorsata. Venom profiles and cross-reactivity of A. dorsata and Apis mellifera were compared, to ascertain whether venom of A. mellifera can be used for diagnosis in A. dorsata allergy. Both venom profiles were similar by High Performance Liquid Chromatography and SDS-PAGE. Sera of 29 of 30 (96.7%) patients with anaphylaxis to A. dorsata stings had IgE to the phospholipase-2 (PLA2) doublet (15 and 16 kDa) of A. dorsata venom by immunoblot, compared to 26 of 30 (86.7%) with the PLA2 of A. mellifera and a purified preparation of PLA2. Twelve patients (40%) with severe anaphylaxis had IgE reactivity to a 39 kDa protein band of venom of both species, a third band, identified in immunoblot as hyaluronidase. The cross-reactivity of PLA2 and hyaluronidase of A. dorsata and A. mellifera were further confirmed by immunoblot inhibition results. Twenty five of 30 (83.3%) of our patients had positive venom specific IgE (>0.35 KUA/L) reactivity to Phadia ImmunoCAPs of A. mellifera venom. The observed IgE cross reactivity suggests the possibility of using A. mellifera venom as a diagnostic test for A. dorsata venom allergy.

PCR detection and typing of human papilloma virus DNA in squamous carcinoma of the cervix in a cohort of Sri Lankan women.

OBJECTIVE: To determine the prevalence of human papilloma virus (HPV) types 16 and 18 in squamous carcinomas of the cervix in Sri Lanka. DESIGN: Case control study. SETTING: One gynaecological unit at the Cancer Institute, Maharagama, Sri Lanka. PATIENTS: 15 patients with squamous carcinoma of the cervix, and 15 age matched controls with histologically normal cervices. MEASUREMENTS: DNA was extracted from paraffin embedded cervical biopsies. Polymerase chain reaction was performed on extracted DNA employing primers specific for HPV types 16 and 18. RESULTS: HPV 16 DNA was detected in 11 out of 15 cervical cancer biopsies (73.3%), in comparison with 3 out of 15 normal controls (20%). HPV 18 was detected in 3 out of 15 cervical cancer biopsies, but not in a single control biopsy. CONCLUSION: Despite the limited number of cases in this cohort, this study supports the strong association between HPV 16 and squamous cancer of the cervix.

A case of hyper-IgE syndrome.

Hyper-IgE syndrome, a multi-system disorder affecting dentition, skeletal and immune systems and connective tissues, presents with recurrent infections and dermatitis. We report here the first case in Sri Lanka.