Prevalence of hypersensitive pneumonitis specific IgG antibodies in the Indian population: A retrospective study

Identifying the underlying antigen responsible for Hypersensitivity Pneumonitis (HP) in patients poses a significant challenge within the confines of a typical clinical environment. Our primary objective in this study was to investigate the distribution and prevalence of G antibodies among individuals diagnosed with HP, taking into account factors such as age, gender, and geographical location. A retrospective study spanning 5 years (from January 2018 to June 2023) was conducted, involving patients over the age of 18 who had undergone screening for HP. Data collected from 1087 patients was analysed, and the patients were categorized based on age, gender, location, and their antibody status. Out of the total cohort of 1087 patients, 62.47% were female, while 37.53% were male. The overall positivity rate for HP panel testing was determined to be 49.22%. Among the patients subjected to testing, 174 individuals (16.01%) tested positive for at least one specific antibody. Notably, among patients aged 18 to 30 years, Penicillium emerged as the most prevalent (48.28%), closely followed by fumigatus Fumigatus (44.83%). In contrast, for patients aged 31 to 45 years, Pigeon serum feathers exhibited the highest prevalence (39.69%). Moreover, the positivity rates varied across different regions in India. HP can be attributed to an array of agents commonly encountered in both workplace and home settings, encompassing microorganisms, animal and plant proteins, as well as organic and inorganic chemicals. Discerning the causative antigen not only holds immense value for physicians in optimizing patient treatment but also plays a pivotal role in pinpointing the source of exposure. Armed with this knowledge, physicians can provide patients with tailored advice to minimize their exposure risk, potentially leading to disease stabilization or even reversal. In summary, the successful identification of the etiologic antigen emerges as a formidable tool for enhancing the overall quality of patient care.