An update in ada as a diagnostic tool.pptx new

An Update in ADA as A An Update in ADA as A Diagnostic ToolDiagnostic Tool

DR.AMINA NURRESIDENT,PHASE-AINTERNAL MEDICINEBSMMU

What is ADAWhat is ADAAdenosine deaminase (also known as

Adenosine aminhydrolase, or ADA) is an enzyme involved in purine metabolism.

Needed for the breakdown of adenosine from food and for the turnover of nucleic acids in tissues.

Present in virtually all mammalian cells, its primary function in humans is the development and maintenance of the immune system.[

StructureStructure ADA exists in both small form (as a monomer) and large form

(as a dimer-complex). In the monomer form, the enzyme is a

polypeptide chain, folded into eight strands of parallel α/β

barrels, which surround a central deep pocket that is the

active site.

In addition to the eight central β-barrels and eight peripheral

α-helices, ADA also contains five additional helices: residues

19-76 fold into three helices, located between β1 and α1

folds; and two antiparallel carboxy-terminal helices are

located across the amino-terminal of the β-barrel.

StructureStructure

There are 2 isoforms of ADA: ADA1 and ADA2.

ADA1 is found in most body cells,

particularly lymphocytes and macrophages.ADA2

was first found in human spleen and in tissues

including the macrophage.

ADA2 is found predominantly in the human

plasma and serum, and exists solely as a

homodimer. In tubercular effusion we detect

ADA2.

Biological FunctionBiological Function

ADA is considered one of the key enzymes of

purine metabolism. Primarily, ADA in human

is involved in the development and

maintenance of the immune system.

However, ADA association has also been

observed with epithelial cell differentiation,

neurotransmission, and gestation

maintenance.

Clinical significanceClinical significance

Adenosine deaminase (ADA) is an endogenous tissue enzyme which is released into the serum in patients with different types of malignancies and infections, including viral hepatitis, infectious mononucleosis, typhoid fever, and tuberculosis.

In pleural fluid, elevated ADA levels are very commonly

associated with tuberculosis.

In CSF, ADA is elevated in cases of tuberculous

meningitis.

Clinical significanceClinical significance

Adenosine deaminase (ADA) deficiency

typically causes severe combined

immunodeficiency (SCID) in infants who

present with growth failure, opportunistic

infections, lymphopenia, and defective

cellular and humoral immune function.

Value of Adenosine Deaminase (ADA) Activity in Value of Adenosine Deaminase (ADA) Activity in Tubercular SerositisTubercular Serositis

Tuberculosis is one of the oldest and commonest

infectious diseases which usually affects lung but

extra pulmonary tuberculosis is also common, of

which serosal tuberculosis is one.

The diagnosis of extra pulmonary tuberculosis

requires investigation of pleural fluid

biochemistry, cytology and pleural biopsy.

Value of Adenosine Deaminase (ADA) Activity in Value of Adenosine Deaminase (ADA) Activity in Tubercular SerositisTubercular Serositis

Positivity for AFB and Histopathological study of pleura is

very low and culture is very time consuming. ELISA, PCR &

Interferon are very expensive tests.

Adenosine deaminase has been proposed to be a useful

surrogate marker for tuberculosis in pleural, pericardial and

peritoneal fluids.

The ADA assay principle is based on the detection of either

hydrogen peroxide or ammonia after enzymatic deamination

of adenosine to inosine by ADA.

VALUE OF ADENOSINE DEAMINASE (ADA) VALUE OF ADENOSINE DEAMINASE (ADA) ACTIVITY IN TUBERCULAR SEROSITISACTIVITY IN TUBERCULAR SEROSITIS

The increase in the ADA activity in patients with TB may indicate the cellular

immune response and T lymphocyte activation in the disease.

T lymphocytes have ADA level 10 to 12

times higher than B lymphocytes. ADA activity

varies depending on the proliferative status and

maturity of cells.

Adenosine Deaminase (ADA) Adenosine Deaminase (ADA) Level in Tubercular Pleural Level in Tubercular Pleural EffusionEffusion

Pleural effusion is a common chest problem,

yet it is difficult to establish the aetiological

diagnosis in as many as 20% cases in spite

of good history, thorough clinical, radiological,

full examination of aspirated fluid and pleural

biopsy1. So as a simple, rapid and reliable

diagnostic test we need ADA to establish the

aetiology of pleural effusion.

Adenosine Deaminase (ADA) Level in Tubercular Adenosine Deaminase (ADA) Level in Tubercular Pleural EffusionPleural Effusion

In a journal of Lung India, an official

publication of Indian chest society ,it has

been concluded that If 36 IU/L is taken as

cut of limit the sensitivity and specificity of

ADA for tuberculosis is 100 % and 77.7 %.

More than 100 IU/L was exclusively seen in

tubercular pleural effusion.


According to Southeast Asian J Trop Med Public

Health Study, the lowest cutoff value for enzyme

activity in pleural fluid of patients with TB was 45

IU/l and the sensitivity and specificity for diagnosis

were 76.10% and 100%, respectively.

Therefore, the measurement of ADA in tubercular

pleural effusion has a utility in the diagnosis of

tuberculosis when other clinical and laboratory tests

are negative.


In European Respiratory Journal, it has been stated that in tuberculous exudates, with diagnostic thresholds of 47IU/L.

Sensitivities of ADA, for tuberculosis were 100%.

Their specificities 91% and Their efficiencies 93%.

Adenosine Deaminase (ADA) Level in Tubercular Adenosine Deaminase (ADA) Level in Tubercular Pleural EffusPleural Effusionion

According to American College of Chest Physicians journal CHEST, Specificity is 97% and sensitivity 100% when a value of more than 45 U/L is considered.

In another article of the same journal it is stated that The reliability of the early diagnosis of pleural tuberculosis has been greatly improved by the use of adenosine deaminase (ADA) .

Adenosine Deaminase (ADA) Adenosine Deaminase (ADA) Level in Tubercular Pleural Level in Tubercular Pleural EffusionEffusion

Determination of the ADA level in the

suspected pleural fluid appears to be the

most promising marker because of the ease,

rapidity, and cost-effectiveness of the ADA

assay . Sensitivity and specificity of elevated

level of ADA in the tuberculous pleural fluid

ranges from 91 to 100% .


In Bangladesh a research regarding ADA as a

diagnostic tool was done by Department of

Medicine, National Institute of Disease of the

Chest and Hospital, Dhaka

Department of Clinical Biochemistry, Lab

Medicine, Apollo Hospital, Dhaka, Bangladesh

Department of Respiratory Medicine, Dhaka

Medical College, Dhaka


This study has clearly shown that ADA levels

are significantly high in patients with

tubercular pleural effusion (68.7±37.0U/L)

compared to that (28.6±8.3 U/L) in non

tuberculous group.

Sensitivity (94%) and specificity (88%) of the

test in tubercular pleural effusions when cut

off value set at 40U/L.

Value of adenosine deaminase (ADA) in ascitic Value of adenosine deaminase (ADA) in ascitic fluid for the diagnosis of tuberculous peritonitisfluid for the diagnosis of tuberculous peritonitis

Tuberculous peritonitis remains a diagnostic

challenge for clinicians.

Many studies have done for assessing the

usefulness of adenosine deaminase (ADA) in

ascites for the diagnosis of tuberculous

peritonitis.

However, the overall diagnostic accuracy of ADA

for tuberculous peritonitis is given here

according to some authentic clinical research.


According to a study result published in

Pubmed done on 2006 ADA levels showed

high sensitivity (100%) and specificity (97%)

using cut-off values from 36 to 40 IU/L.

Optimal cut-off point was determined at 39

IU/L.


Another study in Sao Paolo in 1995 shows cut-off value of >

31 U/l, the sensitivity, specificity and positive and negative

predictive values were 100%, 92%, 72% and 100%,

respectively.

They conclude that ADA determination in ascitic fluid is a

useful and reliable screening test for diagnosing tuberculous

ascites.

Values of ADA higher than 31 U/l indicate more invasive

methods to confirm the diagnosis of tuberculosis.


In European pub Med central journal Department of

Gastroenterology, M.L.N. Medical College, Uttar

Pradesh, India published that At a cut-off value

of greater than 33 U/L, the sensitivity, specificity,

positive and negative predictive value, and the

overall diagnostic accuracy for

diagnosing tuberculous ascites were

100%,96.6%,95%, 100% and 98% respectively.


Another article in The Lancet Journal reviewed

ADA an asset for distinguishing tuberculosis from

other causes of ascites.

The mean ADA activity was 45 U/L for patients

with Tuberculous ascites and 36.7 U/L in those

with other causes of ascites like alcoholic

cirrhosis, cryptogenic cirrhosis, malignant

disorders, pancreatitis and miscellaneous

causes.


In this study ADA has a sensitivity of

100% and specificity of 96%. These

studies suggest that the ascitic fluid

adenosine deaminase activity may be

used to identify patients in whom the

diagnosis of abdominal tuberculosis may

be pursued.


Science Direct journal published their abstract

which was almost same.

A cut-off level of 30 U/L for the diagnosis of

tuberculous peritonitis was found to yield the best

results; corresponding sensitivity and specificity was

94% and 92%, respectively.

No statistically significant difference in ADA activity

was observed when tuberculous ascites occurred in

the absence or presence of cirrhosis.

Diagnostic value of adenosine deaminase in Diagnostic value of adenosine deaminase in cerebrospinal fluid for tuberculous meningitiscerebrospinal fluid for tuberculous meningitis

The diagnosis of TBM is complicated as it causes

various clinical manifestations, which overlap with

those of other chronic diseases of the central

nervous system (CNS) such as viral and pyogenic

meningitis.

The initiation of anti TB medication in suspected

TBM patients can often be delayed because of a

lack of confidence in the presently available

laboratory tests .


According to Oxford journal of infectious disease the

sensitivity of CSF ADA for diagnosing tuberculous

meningitis was 10.05 and specificity 99% .

A significant rise in levels of enzyme was observed

during the first 10 days of therapy, was followed by a

gradual decline, and reached normal values after three

to four months of treatment.

The test proved to be a simple and reliable method for

early diagnosis and follow-up of tuberculous meningitis.


In a research of Biochemistry Research Laboratory,

Central India Institute of Medical Sciences,

demonstrated that ADA activity in the CSF of TBM

patients, using a cutoff value 11.39 U/L/min, can be

useful for the early differential diagnosis of TBM.

This test can be performed in any pathology

laboratory where more sophisticated methods are

not available. The sensitivity of the test for positive

diagnosis was 82% and the specificity was 83%


Department of Internal Medicine, Division of

Infectious Diseases, Asan Medical Centre, Ulsan

University College of Medicine, South Korea

studied an adenosine deaminase (ADA) activity in

the cerebrospinal fluid (CSF) and the result was

ADA activity >15 U/l could be a strong indication of

tuberculous meningitis and determination of CSF

ADA can aid in the early differential diagnosis of

tuberculous meningitis.


The Journal of Tropical Medicine and Hygiene

reported Cerebrospinal fluid adenosine

deaminase levels differentiate

tuberculous meningitis cases from those

with aseptic meningitis being higher than

4 U/L in all and higher than 6 U/L in 90%

cases of tuberculous meningitis.

The Use of Adenosine Deaminase as Diagnostic The Use of Adenosine Deaminase as Diagnostic Tools for Tuberculous PericarditisTools for Tuberculous Pericarditis

Traditional diagnostic tests for pericardial tuberculosis

(TB) are insensitive and often require long culture

periods, and this has led to more emphasis being placed

on biochemical tests such as the pericardial adenosine

deaminase (ADA) test.

The median ADA level in the tuberculous group was 71.7

U/L (range, 10.3 to 303.6 U/L), which was significantly

higher than that in any other group like malignancy, non

tuberculous infections ,other effusions, and effusions of

uncertain origin.

The Use of Adenosine Deaminase as Diagnostic The Use of Adenosine Deaminase as Diagnostic Tools for Tuberculous PericarditisTools for Tuberculous Pericarditis

According to Europian Heart Journal, there was a

positive correlation between high adenosine

deaminase values and the development of

constrictive pericarditis. In this study, two patients

required pericardectomy. Therefore, the

adenosine deaminase value is a significant

prognostic indicator for the development of

constrictive pericarditis in tuberculous

pericarditis.

Diagnostic Value of Adenosine Deaminase in Diagnostic Value of Adenosine Deaminase in Tuberculosis With HIV CoinfectionTuberculosis With HIV Coinfection

The global incidence of tuberculosis (TB)

has sharply increased, particularly in

areas where HIV and TB are both

prevalent. Tuberculous pleuritis (TBpl)

has been noted to be more common in

patients coinfected with HIV and TB than

in patients without HIV infection.


Production of the enzyme Adenosine Deaminase in

pleural fluid reflects the presence of activated T

lymphocytes and monocytes. Therefore, it is

expected that ADA will be lower in HIV co-infected

patients and/or other immunocompromised patients

with low blood CD4 counts.

ADA analysis is a sensitive marker of tuberculous

pleuritis even in HIV patients with very low CD4

counts in a high TB endemic region.


According to CHEST journal the best cutoff at 60 U/L,

yielding measures for sensitivity (0.95), specificity (0.96),

positive predictive values (PPVs; 0.96), and negative

predictive values (0.95). the diagnostic value of ADAPF

is independent of HIV serologic status.

According to PLOS ONE journal the cut-off value of ADA

30 U/L, the overall sensitivity, specificity, positive

likelihood ratio, and negative likelihood ratio of ADA was

94%, 95%, 19, and 0.06 respectively.


The mean CD4 cell counts among TB pleuritis

patients were 29 and 153 cells/microL in patients

with CD4 <50 cells/microL and >50 cells/microL,

(p<0.05) respectively.

The corresponding mean ADA values for these

patients were 76 U/L and 72 U/L respectively

(p>0.5). There was no correlation between ADA

values and CD4 cell counts (r = −0.120, p =

0.369).


Even at CD4 counts of less than 10cells/microL,

the ADA values were still above the cut-off. they

also did not find any correlation between ADA

values and CD4 cell counts in another cohort of

South African HIV infected TB pleuritis patients .

This may be due to higher immune activation in

HIV positive patients with very low CD4 counts .


One explanation could be that the

isoenzyme ADA-2 which contributes

significantly to total ADA in diagnosing TPE

is found mainly in the monocytes which are

not significantly affected in HIV patients

compared to CD4 T-lymphocytes.

Serum and synovial fluid adenosine deaminase Serum and synovial fluid adenosine deaminase activity in patients with rheumatoid arthritis, activity in patients with rheumatoid arthritis, osteoarthritis, and reactive arthritis.osteoarthritis, and reactive arthritis.

A Research article of Eular journal assessed the value of

joint fluid ADA level in the diagnosis of synovial swellings.

Increased activity was found in the synovial fluid taken

from patients with rheumatoid disease and reactive

arthritis, though values were less raised in the later.

Synovial fluid taken from patients with osteoarthritis did not

show significantly raised adenosine deaminase activity as

compared with that of normal controls

Serum adenosine deaminase activity in patients Serum adenosine deaminase activity in patients with systemic lupus erythematosuswith systemic lupus erythematosus

In Systemic lupus erythematosus (SLE) Although

most infections are caused by Gram-positive or

Gram-negative bacteria, there is an increase in the

incidence of Mycobacterium tuberculosis and other

opportunistic infections.

SLE and tuberculosis (TB) interact in complicated

ways - they may have similar presentation and may

mimic each other.

Serum adenosine deaminase activity in Serum adenosine deaminase activity in patients with systemic lupus patients with systemic lupus erythematosuserythematosus

Higher prevalence of tuberculous infections in

SLE is attributed to multiple immune

abnormalities that occur in these patients as well

as to immunosuppressive therapy.

High doses of corticosteroids are also a major

risk factor. Also, uncontrolled hyperactivity of the

immune system actually makes SLE patients an

immunocompromised host.


Resistance to MTB, which is mediated by cellular

immunity, is deficient in SLE patients both due to the

nature of the disease and the immunosuppressive

therapy.

A Spanish study found that the incidence of TB was six-

fold higher in the SLE group compared to the general

population.

Similarly, Hong Kong reported a five- to 15-fold higher

risk and from India, a 10-60-fold higher risk was

reported.


Confirmation of clinical suspicion of TB is

hindered by several factors.

TB presenting in a miliary pattern or with

mediastinal lymphadenopathy, or as extra-

pulmonary disease, poses a great diagnostic

challenge because these presentations may

point to a bacterial etiology or to other

diseases such as lymphomas.

Serum adenosine deaminase activity in Serum adenosine deaminase activity in patients with systemic lupus patients with systemic lupus erythematosuserythematosus

Also, extrapulmonary TB usually presents with

symptoms like persistent fever, arthralgia, arthritis,

anemia and pleural and pericardial effusion, which are

common in other diseases and may mimic SLE flares as

well.

Because extrapulmonary involvement is more common

in SLE patients, it often requires tissue and body fluid

analysis for diagnosing TB and thus may take a longer

period to establish definitive diagnosis.


Estimation of ADA levels in body fluids is a

valuable tool in establishing total TB. ADA

levels ≥42 IU/L are considered to be highly

suggestive of TB, with one study reporting a

sensitivity of 100%.

..Serum adenosine deaminase activity and its Serum adenosine deaminase activity and its isoenzyme pattern in patients with systemic lupus isoenzyme pattern in patients with systemic lupus erythematosuserythematosus

Department of Connective Tissue Biochemistry,

University of Camerino, Italy. Published their

study in EUROPE PUBMED CENTRAL

JOURNAL about relation of ADA and SLE.

According to their study Serum tADA activity

was significantly increased in patients compared

to healthy controls (mean +/- SD; 476.9 +/- 145.3

vs 254.0 +/- 98.9 ncat/L, p < 0.001).

Serum adenosine deaminase activity and Serum adenosine deaminase activity and its isoenzyme pattern in patients with its isoenzyme pattern in patients with systemic lupus erythematosussystemic lupus erythematosus The isoenzyme analyses showed that the

increased total ADA activity in the patients

was mainly due to increased ADA2 activity

(371.3 +/- 154.8 vs 214.2 +/- 47.9 ncat/L in

healthy controls, p < 0.001). The mean

values for ADA1 activity in the patients (64.6

+/- 37.9 ncat/L) and healthy controls (69.2 +/-

26.9 ncat/L) were similar.

Serum adenosine deaminase activity and its Serum adenosine deaminase activity and its isoenzyme pattern in patients with systemic lupus isoenzyme pattern in patients with systemic lupus erythematosuserythematosus

A strong correlation was found between

serum ADA activity and disease activity as

measured by ECLAM (Spearman's rank

correlation coefficient 0.74, p < 0.0001, linear

regression coefficient 0.68, p < 0.01). Total

serum ADA activity (tADA) was measured

spectrophotometricall

summarysummary

ADA Level in tuberculous pleural effusion ranged from

35-160 U/L with a mean level of 100U/L and sensitivity

and specificity of 100%.

ADA level in tuberculous peritoneal effusion ranged

from 30-135 U/L with a mean level of 92U/L and

sensitivity and specificity of 100% and 95%.

ADA level in tubercular pericardial effusion ranged from

63-117 U/L with a mean level of 90U/L and sensitivity

and specificity of 100% and 83.3% respectively.

Table 1. ADA level in serosal fluidTable 1. ADA level in serosal fluid..

Type Range (U/L) Mean (U/L)

Pleural Fluid

Tuberculous 35-160 100

Non-tuberculous

5-33 18

Peritoneal Fluid


Non-tuberculous

1-28 12

Pericardial Fluid


Non-tuberculous

1.5-29 15.33

Table 2.Table 2. Correlation of ada results with bacteriological Correlation of ada results with bacteriological results in pleural fluid, histopathology of biopsized pleural results in pleural fluid, histopathology of biopsized pleural tissue and mt test among tuberculous pleural effusion tissue and mt test among tuberculous pleural effusion cases, n = 62cases, n = 62

ADA in pleural fluid

M/E for AFBPositive

Culture forM. TBPositive

Biopsy forGranulomaPositive

Tuberculin TestPositive

ADA Positive

6(10.34) 12(20.68) 27(46.55) 42(72.41)

ADA Negative

n=4

0(0.00) 2(50.00) 0(0.00) 0(0.00)

Totaln=62

6(9.62) 14(22.50) 27(43.54) 42(67.74)

Table 3.Table 3. Comparison of Sensitivity, Specificity, Positive predictive Comparison of Sensitivity, Specificity, Positive predictive value, Negative predictive value and Accuracy of ADA assay with value, Negative predictive value and Accuracy of ADA assay with every parameter studied for diagnosis of TPEevery parameter studied for diagnosis of TPE

ADAlevel

test Pleural biopsy

Pleural fluidculture forM.TB

Pl eural fluidAFB

Sputumculture for

SputumAFB

Sensitivity 0.94 0.68 0.44 0.23 0.10 0.15 0.10

Specificity 0.88 0.93 1.00 1.00 1.00 1.00 1.00

PPV 0.92 0.93 1.00 1.00 1.00 1.00 1.00

NPV 0.90 0.66 0.54 0.46 0.42 0.69 0.68 Accuracy 0.90 0.78 0.66 0.53 0.46 0.71 0.69

Table 4.Table 4. ADA results in pleural fluid among the ADA results in pleural fluid among the nontubercular pleural effusion cases, N = 41nontubercular pleural effusion cases, N = 41

Non Tuberculous

Cases

Number of cases

ADA Positive ADA Negative

Malignant n=30 3(10.0) 27(90.0)

Pneumonia n=8 1(12.5) 7(87.5)

Rheumatoid Arthritis

n=1 1(100) 0(0.00)

Nephrotic Syndrome

n=1 0(0.00) 1(100)

Congestive Cardiac Failure

n=1 0(0.00) 1(100)

Total n-41 5(12.20) 36(87.80)

Table 5. The mean ADA values in the Table 5. The mean ADA values in the different diagnostic category.different diagnostic category.

Case Mean ADA (U/L) +SD

Malignancy (N-26)* 12.9 +13.1

Congestive Heart Failure (N-12)

7.16 + 6.2

Streptococcus Pneumoniae Infection (N-1)

11

KlebsiellaPneumoniae Empyema (N-1)

200

TotalTB Peuritis (N-197) 71.2 + 39.6

SD-Standard Deviation*Kaposi’s Sarcoma is the only malignancy with the ADA of 73 above the cut off

referencesreferences Pub Med.gov European PubMed Central CHEST journal Research Gate Lung India European Respiratory Journal BioMed Central Journal of Internal Medicine (JIM) PLOS ONE Science Direct Journal The Eular Journal SAGE Journal

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An update in ada as a diagnostic tool.pptx new

Health & Medicine

Transcript of An update in ada as a diagnostic tool.pptx new