Identification of chronic obstructive pulmonary disease subgroups in 13 Asian cities.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition that can differ in its clinical manifestation, structural changes and response to treatment. OBJECTIVE: To identify subgroups of COPD with distinct phenotypes, evaluate the distribution of phenotypes in four related regions and calculate the 1-year change in lung function and quality of life according to subgroup. METHODS: Using clinical characteristics, we performed factor analysis and hierarchical cluster analysis in a cohort of 1676 COPD patients from 13 Asian cities. We compared the 1-year change in forced expiratory volume in one second (FEV1), modified Medical Research Council dyspnoea scale score, St George's Respiratory Questionnaire (SGRQ) score and exacerbations according to subgroup derived from cluster analysis. RESULTS: Factor analysis revealed that body mass index, Charlson comorbidity index, SGRQ total score and FEV1 were principal factors. Using these four factors, cluster analysis identified three distinct subgroups with differing disease severity and symptoms. Among the three subgroups, patients in subgroup 2 (severe disease and more symptoms) had the most frequent exacerbations, most rapid FEV1 decline and greatest decline in SGRQ total score. CONCLUSION: Three subgroups with differing severities and symptoms were identified in Asian COPD subjects.

Polymerase chain reaction - restriction fragment length polymorphism analysis for the differentiation of mycobacterial species in bronchial washings.

OBJECTIVES: To identify mycobacterial species in bronchoscopy specimens with a simple assay based on polymerase chain reaction and restriction enzyme digestion. METHODS: Sputum smear negative, bronchoscopy specimens (n=202) were collected from patients attending the Central Chest Clinic and the Teaching Hospital Kandy, Sri Lanka. DNA, extracted from the mycobacterial cultures (n=43) were amplified using known mycobacterial specific Sp1 and Sp2 primers. Resulting products were digested with HaeIII and CfoI restriction enzymes and DNA sequencing was performed for the selected isolates. RESULTS: Among the culture positive patients, PCR was able to distinguish 12 rapid growers (~280-320 bp), 15 slow (~200-220 bp) and 10 patients having both rapid and slow and one having two rapid growing mycobacteria. DNA Sequence analysis revealed the presence of M. intracellulare (n=3), M. phocaicum (n=7), M. tuberculosis complex (n=13), Nocardia (n=2), M. smegmatis (n=1) and Mycobacterium sp (n=12). The identified organisms got digested upon exposure to HaeIII restriction enzyme whereas when exposed to CfoI, only M. phocaicum yielded 80 bp and 230 bp DNA fragments while others remained undigested. Consequently, six patients were confirmed to have M. tuberculosis complex, seven had both M. tuberculosis and non-tuberculosis bacteria (NTM) in their bronchoscopy specimens while 21 had NTM. CONCLUSIONS: Optimised PCR-RFLP assay was able to differentiate M. tuberculosis complex bacteria from nontuberculosis mycobacteria and Nocardia. Molecular analysis confirmed the presence of NTM in bronchoscopy specimens and according to the study a significant proportion of patients (13% to 14%) of the study population were found to have NTM in their bronchial washings.

Myasthenia gravis: a rare cause of orthopnoea due to bilateral diaphragmatic paralysis.

A case of a 68-year-old patient with bronchial asthma who presented with orthopnoea and respiratory failure in supine position is presented.

A case series of symptomatic ocular tuberculosis and the response to anti-tubercular therapy.

OBJECTIVE: To identify the clinical pattern of symptomatic ocular tuberculosis (OTB) and the outcome following antitubercular therapy (ATT) in an endemic setting. DESIGN: A descriptive case series. SETTING: Tuberculosis and ophthalmology clinics, Teaching Hospital, Kandy, Sri Lanka. METHOD: We followed up patients with OTB on standard six-month regimen of ATT, from January 2006 to December 2008. Serial opthalmological assessment were done at the beginning and end of therapy and in each clinic visit. Relevant investigations were performed. Objective improvement of visual acuity was considered the primary clinical outcome. RESULTS: Tuberculous uveitis was the commonest manifestation observed in eighteen of twenty-three patients with symptomatic OTB. Retinal vasculitis (2), episcleritis (1), optic neuritis (1) and an inflammatory scleral nodule (1) were observed in the rest. Seventeen had Mantoux positivity over 15mm. Out of the seventeen patients (age range 25-74 years; 9 males) who completed ATT, fifteen had poor pre-treatment visual acuity, which improved in nine. Keratic precipitates, anterior segment cells, flaring, vitritis and macular oedema had resolved in majority. In patients who deteriorated despite therapy, retinal vasculitis with vitreous haemorrhage (1) and branch vein occlusion (1), persistent macular oedema (2), choroidal scar (1) and optic atrophy (1) were noted. CONCLUSION: OTB may present with varying manifestations, of which uveitis is the commonest. Majority with symptomatic OTB had a highly positive Mantoux test. Favourable clinical outcome with ATT was seen in patients who presented with uncomplicated disease. Standard regimen of ATT did not appear to be effective in patients with complications.