BY DR KARTIK SOOD JUNIOR RESIDENT

DEPARTMENT OF PULMONARY MEDICINE ELMCH

ALKALINE PHOSPHATASE:

DISTINGUISHING BETWEEN

TUBERCULOUS AND NON

TUBERCULOUS PLEURAL EFFUSION

ORIGINAL ARTICLE-LUNG INDIA VOL-26,ISSUE 3,SEPT 2009JAYASHREE SUHASASHISH JADHAV

INTRODUCTION

Tuberculosis is one of the important causes of exudative pleural effusion in our country.

Other causes- Neoplastic diseases • Metastatic disease • Mesothelioma

Infectious diseases • Bacterial infections • Fungal infections • Viral infections • Parasitic infections

Pulmonary embolization Gastrointestinal disease

Esophageal perforation Pancreatic disease Intraabdominal abscesses Diaphragmatic hernia After abdominal surgery Endoscopic variceal

sclerotherapy After liver transplant

Collagen-vascular diseases Rheumatoid pleuritis Systemic lupus

erythematosus Drug-induced lupus Immunoblastic

lymphadenopathy Sjögren's syndrome Wegener's granulomatosis Churg-Strauss syndrome

• Trapped lung • Radiation therapy • Post-cardiac injury

syndrome • Hemothorax • Iatrogenic injury • Pericardial disease • Chylothorax• Post-coronary

artery bypass surgery

• Asbestos exposure

• Sarcoidosis• Uremia • Meigs' syndrome • Yellow nail

syndrome• Drug-induced

pleural disease • Nitrofurantoin • Dantrolene • Methysergide • Bromocriptine • Procarbazine • Amiodarone

Light’s criteria Pleural fluid protein/serum

protein >0.5 Pleural fluid LDH/serum LDH >0.6 Pleural fluid LDH more than two-

thirds normal upper limit for serum

Modified light’s criteria: Pleural fluid cholesterol level >

60mg/dl Serum albumin minus pleural

fluid albumin level ≤ 1.2g/dl

•Various parameters have been used to differentiate tuberculous from nontuberculous pleural effusion.•These include: Pleural fluid(PF) adenosine deaminase, PF lysozyme, PF gamma interferon, PF alpha 1 antitrypsin,PF protease inhibitors,PF CA 125, PF tumor necrosis factor, PF interleukin-1,PF polymerase chain reaction,and reported to be elevated in tuberculous pleural effusionAlkaline phosphatase (ALP) is one of the biochemical markers found in pleural effusion. Previous studies have used ALP to differentiate between exudates and transudates.

This study was thus undertaken to confirmthe usefulness of ALP activity in differentiating tuberculous from nontuberculous pleural effusion.

Patients with pleural effusion and suffering from varying etiologies, were included and routine laboratory tests of pleural fluid were carried out (total proteins, glucose, and pleural fluid Cytology). Pleural fluid samples were cultured and pleural biopsy was done to obtain a definitive diagnosis.

the study was divided into two groups:tuberculous (30) and nontuberculous pleural effusion (30). Nontuberculous group consist of malignanteffusion, parapneumonic effusion, empyema, rheumatoid arthritis, systemic lupus erythematosus, liver abscess,nephrotic syndrome, acute glomerulonephritis, cirrhosis of liver, congestive cardiac failure, severe hypoproteinemia,and chronic renal failure.

Studies performed on the pleural fluid and serum of all patients are: Pleural fluid ALP concentration (P ALP), serum ALP concentration (S ALP), pleural fluid/serum ALP ratio (P/S ALP ratio). Biochemical analysis of ALP was done

RESULTS WERE

In the group of patients with tuberculous pleural effusion, mean P ALP was

significantly higher as compared to nontuberculous pleural effusion .

Patients with tuberculous pleural effusion had a

significantly higher mean P/S ALP ratio than with nontuberculous pleural effusion.

However,such significant difference was not observed for S ALP levels.

VALUES

PF ALP level greater than 71 was observed in 27 out of 30 cases of tuberculous pleural effusion and six out of 30 cases of nontuberculous pleural effusion .

PF/S ALP ratio greater than 0.51 was observed in 27 out of 30 cases of tuberculous pleural effusion and 4 out of 30 of non tuberculous pleural effusion

DISCUSSION

Result confirms that alk phs activity is useful in differentiating tuberculous and non tuberculous effusion

a cut-off value of ≥71 IU/L for pleural alkaline phosphatase activity; and a cut-off value of

≥0.51 for pleural fluid/serum alkaline phosphatase ratio.