Blood Eosinophils as a Switch for Inhaled Steroids in Indian COPD Clinics
COPD clinics in India still hand out inhaled corticosteroids by habit. Many patients leave with a triple inhaler after one noisy chest. Blood eosinophils offer a cheaper way to decide who actually needs the steroid. The test is a cell count, not a CT scan. Used well, it can cut pneumonia and TB risk without abandoning people who flare on bronchodilators alone.
Guidelines already treat the eosinophil as a trait. Counts around 300 cells per microlitre or higher, plus repeated exacerbations, support adding an ICS to a long-acting bronchodilator. Counts under 100 cells per microlitre argue against the steroid in most stable patients. The middle band is a judgement call. Exacerbation history then weighs more than a single number.
Indian rooms complicate that rule. Post-TB obstruction is common. Asthma–COPD overlap hides in the same queue. Biomass smoke and dusty work blur phenotypes. A “COPD” label may sit on a person who still has type-2 inflammation. It may also sit on a scarred lung that will only collect infection if steroids are added. One blood draw cannot replace a good history. It can stop the default triple inhaler.
Safety is the local reason to measure. ICS raise pneumonia risk. In a country with a high TB background, they also raise concern about reactivation when used without need. Eosinophil-guided de-escalation gives the clinic a written rationale to drop the steroid after a quiet year. That is different from never starting it in a frequent exacerbator with high counts.
The test has limits. A course of oral steroids suppresses the count. A recent infection can move it. Timing therefore matters. Draw the sample when the patient is stable and off systemic steroids. Repeat if the first result and the story disagree. Laboratories must report cells per microlitre, not only a percentage. Staff must know the thresholds they are using.
Cost arguments cut both ways. A complete blood count is cheap and widely available. Biologics and FeNO are not. For district clinics, eosinophils are the practical biomarker. The hidden cost is wrong action: leaving a high-count exacerbator on two bronchodilators, or parking a low-count patient on high-dose ICS for life.
Implementation is a clinic habit, not a poster. Put the last eosinophil on the OPD slip next to last year’s exacerbation count. Review ICS at each visit the way you review blood pressure drugs. Teach that a low count is a reason to stop the steroid, not a reason to ignore future flares.
In short, blood eosinophils will not sort every Indian COPD file. They will sort many of them better than brand memory. Use the count with exacerbation history and TB risk. Then start, keep, or withdraw the inhaled steroid on purpose.