DIAGNOSTIC VALUE OF SPUTUM INDUCTION Dr. Anirban Dutta2nd year PG

“Things don’t happen .They are made to happen”- JOHN F. KENNEDY

Introduction Non invasive tool in diagnosing

◦Occupational asthma◦COPD◦Lung cancer◦ILDS ◦TB◦Opportunistic infections

Advantages :

Non invasiveSimple SafeEconomical Easily availableAcceptable to most of the patientsRepeatable and ReproducibleServe in monitoring of course and

therapy

MethodsSputum induction is done with

◦Normal saline◦Hypertonic saline◦Uridine Triphosphate Using a Ultrasonic Nebulizer with a output of

1ml/min.Prerequisites

◦Written informed consent◦Using baseline FEV1 or PEFR ◦Pretreatment with 200-400gm of

salbutamol inhalation prior to induction

Use of Beta 2 agonists for sputum induction is also documented

FEV1,PEFR fall>20% - STOP Procedure

SAMPLE PROCESSINGProcessed within 2hrsCan be stored at -20°C or -40°C in

dimethyl sulfoxide solution .Fluid phase mediators can be

estimated even to <18hrs of sputum induction

Total cell count is done before centrifugation using a hemocytometer.

Cell viability is determined by a triptan blue exclusion method

Differential count by Wright’s or Giemsa stain

for Eosinophils, Neutrophils,macrophages, lymphocytes and bronchial epithelial cells

Toluidine blue - mast cells and basophils.

Results have better contrast when staining time is increased from 10 mins to 60 minutes

Immunocytochemical staining further improves the yield for mast cells and basophils.

Results differ from Selected sputum and Unselected Sputum

It also differs from the use of ◦Dithiothreitol ◦Delayed processing of the sputum◦Effect of temperature◦Dilution ◦Filtration and centrifugation

Standardization is very important for uniformity of results

Bronchial AsthmaDiscrepancies and lack of correlation with

histological changes and various investigations such as Bronchoscopic findings ,FEV1/PEFR repeat Biopsies and airways Hyperresponsiveness have given place to SPUTUM INDUCTION to evaluate and assess airway inflammation.

Elevated Eosinophilic count of 3% provides a clue for the asthma in 80% & 50% of patients with or without inhaled corticosteriods respectively.

Thus eosinophilic count can help in◦evaluation of therapeutic measures i.e

persistence of eosinophils shows either non compliance or acute exacerbation

◦Requiring to either increase the dose of inhalation of corticosteroids

◦Addition of another anti inflammatory drugNeutrophilia warrants an attack by viral

infectionIn children , sputum eosinophilia also

well correlates with bronchial hyper-Responsiveness and severity ◦Sputum induction is safer in ChildHood

Chronic Obstructive Pulmonary Disease

Neutrophilic inflammation plays a major role in inferring presence of infection in COPD

Activation of neutrophil signifies Clinical Improvement

Occurrence of eosinophilia in induced sputum in patients of COPD indicates requirement of Inhalational steroids◦Thus can be used as predictor of response

to steroid therapy.

Pulmonary TuberculosisPreferred method over gastric lavage in

ChildrenUseful in dry coughers and smear negative

casesIt can be used for infants and children from

HIV prevalent areasSmear + for AFB increases by 29% with

sputum induction and results are better with 1st day.

It increases case detection rate of smear –ve Pulmonary TB as well as smear +ve pulm. TB

Pneumocystis Carini PneumoniaSputum induction is

◦sensitive ◦Specific◦Low cost ◦Well tolerated method in

immunocompromised patient to diagnose pneumnocystis carinii pneumonia (PCP) in HIV positive patients

LUNG CANCERCytological diagnostic yield by

sputum induction in the central growth as well as lung in the elderly is almost 74%

The diagnostic technique utilized include◦Specific oncogene activation◦Tumor supressor cell deletion◦Genomic instabilty◦Abnormal methylation

Community Acquired Pneumonia

Nebulization technique using Hypertonic saline is preferred in children as recommended by PNEUMONIA ETILOGY RESEARCH FOR CHILD HEALTH (PERCH)in children hospitalized with severe pneumonia provided no C/I exists

Cystic FibrosisTo find infection and inflammation is more

useful in cases with less sputum productionThis procedure is more preferable over BALAdvantages :

◦2 fold increase in sputum production◦Escalated indices of inflammation TLC , absolute

neutrophil count , interleukin levels & neutrophil elastase activity

◦A large number of non squamous cells and higher detection rate of pathogens & colony counts to diagnose CF as compared to spontaneous sample.

Sputum Induction : FUTUROLOGYIt should be routinely suggested for

Nonproductive cough

In sarcoidosis also it is of CHOICE –diagnostic method of BAL with fiberoptic bronchoscope are well correlated with CD4: CD8 ratio and levels of tumor necrosis factor in induced sputum both in pre and post treatment.

Cellular characteristics and presence of mineralogenical particles in induced sputum can also offer help in diagnosis and assesment of patients with mineral dust exposure and extrinsic alveolitis

In obtaining diagnostic yields of ◦lipid laden macrophages in GERD ◦Hemosiderin laden macrophages in Left

ventricular failureSputum induction can offer high

diagnostic yield in pleural TB when there is no evidence of parenchymal pulmonary disease

ConclusionRequires standardization, trained

technicians and back up support of laboratory analysis of microbiological , biochemical and Histopathological Evaluation

New window in diagnosing and assesing various lung disaeases and disorders

Neverthless it requires a proposal for protocol for future directions.

We also need to identify the reason for underuse of this technique

THANK YOU