The Factors Associated With the Formation of Nasal polyp-a Case Control and Descriptive Study

'The Factors Associated With the Formation of Nasal Polyp'

Nasal polyp is a significant health problem with a prevalence of 4%. It is increased in patients with asthma (7-15%), Cystic fibrosis (39-56%) or aspirin intolerance (36-96%).The quality of life (QOL) is worse than in patients suffering from hypertension, migraine, angina pectoris and head & neck cancer as per a previous study by Videler WJM et al.QOL is in comparison to chronic obstructive pulmonary disease.The reason why it develops in some and not in others remains unknown despite the disease being present for centuries.A definite relationship exists in patients with 'Sampter triad': Asthma, non steroidal anti-inflammatory drug sensitivity and nasal polyps. But not all patients with NSAID sensitivity have nasal polyps and vice verse.

Etiology is largely unknown despite the disease being present for centuries. Although the factors like wood stove exposure, smoking, allergic rhinitis, rhino sinusitis have been strongly implicated in literature from various studies, most data available is on ethmoidal polyps.The present study is an attempt to study the association of important risk factors with both antrochoanal(AC) and ethmoidal nasal polyps(EP).One study found that a significantly smaller proportion of the population with polyps were smokers compared to the unselected population (15% v/s 35%). But this is not confirmed by other studies.

Seven percent of asthma patients have nasal polyps and in non atopic asthma and late onset asthma, polyps are diagnosed more frequently (10-15%).Eosinophil numbers are significantly higher in nasal polyp tissue and further increased in patients with co-morbid asthma and aspirin sensitivity.

Nasal colonization in increased amounts was found by Staphylococcus aureus and presence of specific Immunoglobulin E directed against S.aureus enterotoxins was found. Rates of colonization and IgE presence in nasal polyp tissue were increased in subjects with nasal polyp associated with co-morbid asthma and aspirin sensitivity.

Nasal polyps are frequently found to run in families, suggesting a hereditary or with shared environmental factor. In the study by Rugina et al., more than half of 224 nasal polyp patients (52%) had a positive family history while the study by Greisener et.al, reported 14% of family history strongly suggesting hereditary factors in the pathogenesis of nasal polyps.

Some studies have found environmental factors like smoking and those using wood stove as a primary source of heating with the development of nasal polyps. The studies are contrasting.

There is presently a need of understanding the differences in the pathogenesis of antrochoanal polyp and ethmoidal nasal polyp clearly.There are hardly any concrete research performed on them to note the differences in the etiology and their pathogenesis. Hence the study is undertaken to extensively study the etiologies responsible for them and to note the differences.

The present study involves two parts. A case control study wherein the association of nasal polyps with various risk factors like smoking, wood stove exposure, allergic rhinitis, non vegetarian diet intake, rhino sinusitis, deviated nasal septum, occupational dust exposure and eosinophilia.This will be studied individually for antrochoanal and ethmoidal nasal polyps.Again the same will be studied with respect to the recurrent and non recurrent polyps.

A descriptive study focuses on the nasal polyp occurrence with respect to the age, sex, religion, socioeconomic status, urban or rural preponderance,overcrowding, aspirin intolerance, family history etc.

The results will be studies after calculating the odds ratio and the chi square test for whatever data is available. Interpretation will be performed subsequently.

Gene expression profiling would be performed to study the differences in gene expression levels between AC and EP s with respect to risk factors and morphological characteristics.Mutational analysis will be performed to identify mutations in selected genes.

Inclusion Criteria:

1. Antrochoanal and ethmoidal nasal polyps
2. Recurrent nasal polyps
3. Both infected and non infected polyps
4. Both eosinophilic and non eosinophilic polyps

Exclusion Criteria:

1. Exclusive neoplasms of nose and para nasal sinuses
2. Immunodeficiency status like HIV