The document summarizes autoantibody testing and interpretation in common connective tissue disorders. It discusses the discovery of autoantibodies, mechanisms of immune tolerance and autoimmunity. It provides an overview of systemic autoimmune diseases and their diagnostic criteria. It also explains antinuclear antibody testing methods, interpretation of results, and significance of a positive ANA. Specific autoantibodies associated with rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, Sjogren's syndrome and other diseases are also summarized.

1. AUTOANTIBODY TESTING AND
INTERPRETATION IN COMMON CONNECTIVE
TISSUE DISORDERS
Presented by: Dr.Mounika.R.N
Moderator: Dr. Parul Jain

2. CONTENTS
 Introduction
 Discovery of autoantibodies
 Mechanisms of Immune tolerance
 Mechanisms of Auto immunity
 Systemic Auto Immune diseases- Overview and criteria
 Antinuclear antibody testing and interpretation
 ANCA testing and interpretation

3. Introduction
 Autoantibodies are formed due to immune reactions against self antigens
 Evokes the specter of “Horror Autotoxicosis” a term coined by Paul Ehrlich
 Autoimmunity refers to the mere presence T cells or antibodies against self antigens
 This does NOT indicate an autoimmune disease

4. Discovery of auto-antibodies
 The first description of a pathogenic autoantibody was by Donath and Landsteiner in 1904
 They discovered the cause of Paroxysmal Cold Haemoglobinuria
 When RBCs were cooled down in an ice water bath- they were “sensitized” by a serum
factor(antibody)
 When the temperature was raised to body temperature, erythrocytes underwent lysis

5. Discovery of auto-antibodies
 The first detailed descriptions of experimental induction of pathogenic
autoantibodies was by Rose and Witebsky
 They produced autoimmune thyroiditis in rabbits with extracts of thyroid
glands
 Subsequently similar autoantibodies were demonstrated in the comparable
human disease, Hashimoto’s thyroiditis

6. Pathological Autoimmunity criteria
1. Presence of an immune reaction specific for some self antigen
2. Evidence that such a reaction is not secondary to tissue damage but is of
primary pathogenic significance( eg. Animal models or evidence of
transplacental transmission)
3. Absence of another well-defined cause of the disease

7. Mechanisms of Immune tolerance
CENTRAL TOLERANCE
1. Negative selection of self reactive T lymphocytes in Thymus
2. Receptor editing in B lymphocytes
INNATE MECHANISMS
1. PRRs are a simple way to distinguish foreign antigens from self-
antigens.
2. Rapid clearance of apoptotic cells

8. PERIPHERAL TOLERANCE
1. Anergy-Lymphocytes that recognize self antigens
are rendered functionally unresponsive
2. Suppression by regulatory T cells(IL 10 and TGF-β)
3. Deletion by apoptosis
Mechanisms of Immune tolerance

9. Mechanisms of Autoimmunity
EXOGENOUS
1. Molecular Mimicry – Rheumatic heart disease
2. Superantigenic stimulation- TSST1 in Kawasaki disease
ENDOGENOUS
1. Loss of immunologic privilege- Multiple Sclerosis, sympathetic ophthalmia
2. Alteration in self antigens- Rheumatoid arthritis (citrullinated peptides)
3. Defective clearance of apoptotic material – SLE
4. Defects in regulatory T cell function- IPEX syndrome (Immune Dysregulation
Polyendocrinopathy Enteropathy X linked)

10. Mechanisms of tissue injury by autoantibodies
1.Blocking or inactivation of Target Antigen:
 Myasthenia Gravis(Nicotinic Ach receptor)
 Antiphospholipid Antibody Syndrome(Phospholipid β2
glycoprotein complex)
 Insulin Resistant Diabetes Mellitus(Insulin Receptor)
2. Stimulating the target antigen
 Grave’s disease(TSH receptor)
 Granulomatosis with polyangiitis(proteinase 3)

11. Mechanisms of tissue injury by autoantibodies
3. Complement activation – Goodpasture’s Syndrome
4. Immune complex formation
 Systemic Lupus Erythematosus
 Rheumatoid Arthritis
5.Opsonization
 Auto immune haemolytic anemia
 Auto immune thrombocytopenic purpura

12. Mechanisms of tissue injury by autoantibodies
6.Antibody dependent cellular cytotoxicity
 Hashimoto’s Thyroiditis

13. Autoimmune diseases:
Kasper, D. L., Fauci, A. S., Hauser, S. L.,
Longo, D. L. 1., Jameson, J. L., & Loscalzo
J. (2018). Harrison's principles of internal
medicine (20th edition); Chapter 340; Pg

14. SYSTEMIC AUTOIMMUNE DISEASES
MULTIORGAN INVOLVEMENT:
1. Systemic Lupus Erythematosus
2. Systemic sclerosis
3. Sjogren’s syndrome
JOINT INVOLVEMENT(PREDOMINANTLY)
1. Rheumatoid Arthritis
MUSCLE INVOLVEMENT
1. Dermatomyositis
2. Polymyositis
ANCA ASSOCIATED VASCULITIS:
1. Granulomatosis with polyangiitis
2. Churg-Strauss syndrome
3. Microscopic Polyangiitis

15. Rheumatoid Arthritis
 It is a chronic inflammatory disease of unknown
etiology marked by a symmetric, peripheral
polyarthritis.
 RA often progresses to destruction of the articular
cartilage and ankylosis of the joints.

16. Classification criteria for Rheumatoid Arthritis
 A score of ≥6 fulfills
requirements for
definite RA.
Source: Kasper, D. L., Fauci, A. S.,
Hauser, S. L., Longo, D. L. 1.,
Jameson, J. L., & Loscalzo, J.
(2018). Harrison's principles of
internal medicine (20th edition.)
Chapter 351, Page 2530

17. Rheumatoid Factor:
 IgG antibody against Fc fragment of IgG immunoglobulin
 Earlier onset of RF is associated with more severe disease
 Shortcomings of RF
(1) Lack of specificity for RA and
(2)Unclear kinetic and mechanistic connection to pathogenesis
 Method of detection : ELISA
Anti Collagen II antibodies
 It is a joint specific antibody
 Present early in the disease
ANTIBODIES IN RHEUMATOID ARTHRITIS

18. Anti–Cyclic Citrullinated Peptide Antibodies
 Antigen: Citrullinated proteins in RA synovium (fibrinogen, collagen type II, vimentin)
 Clinical importance:
i. High specificity for the diagnosis of RA.
ii. Predictor of development of RA. (RA developed within 3 years in more than 90% of the
patients with undifferentiated arthritis who tested positive for anti-CCP)
iii. Associated with a more severe and destructive disease course
iv. Associated with RA-related interstitial lung disease (ILD) and cardiovascular disease
(CVD)
 Method of detection: ELISA
Antibodies in Rhuematoid Arthritis

19. Systemic Lupus Erythematosus
 An autoimmune disease involving multiple organs, characterized by a vast array of
autoantibodies
 It is typically a chronic, remitting and relapsing, often febrile, illness
 Injury to the skin, joints, kidney and serosal membranes is prominent

20. SLICC criteria
CLINICAL CRITERIA
1. Acute or subacute cutaneous lupus rash
2. Chronic cutaneous lupus
3. Non scarring alopecia
4. Oral or nasal ulcers
5. Joint disease( Synovitis in 2 or more joints OR tenderness
with 30 mins of morning stiffness in 2 or more joints)

21. 6. Serositis( Pleritis OR pericarditis)
7. Renal disorder(Persistent proteinuria >500mg/24 hours OR RBC casts)
8. Neurologic criteria( Seizures,psychosis, mononeuritis multiplex, myelitis OR
acute confusional state)
9. Hemolytic anemia
10. Leukopenia <4000/mm3 OR lymphopenia <1000/mm3
11. Thrombocytopenia < 100,000/mm3

22. Immunologic criteria
1. ANA level above laboratory reference range
2. Anti dsDNA above lab reference range
3. Anti Sm above lab reference range
4. Anti phospholipid antibody
5. Low complement level- Low C3, C4 OR low CH50
6. Positive Direct Coomb’s test
Any 4 out of 17 criteria should be fulfilled
including at least ONE clinical and ONE
Immunologic criteria
OR
Biopsy proven lupus nephritis with any anti
nuclear autoantibody (even if 4 criteria are not
fulfilled)
SPECIFICITY: 93%
SENSITIVITY: 92%
Source: Kasper, D. L., Fauci, A. S., Hauser, S. L.,
Longo, D. L. 1., Jameson, J. L., & Loscalzo, J.
(2018). Harrison's principles of internal
medicine (20th edition.); Chapter 349; Page 2518

23. Best screening test; repeated negative
tests make SLE unlikely
High titers are SLE-specific and in
some patients correlate with disease
activity,nephritis,vasculitis
More frequent in drug-induced
lupus than in SLE
Cutaneous and Neonatal SLE
Correlates with Neuropsychatric manifestations
Source: Kasper, D. L., Fauci, A. S., Hauser, S. L.,
Longo, D. L. 1., Jameson, J. L., & Loscalzo, J.
(2018). Harrison's principles of internal
medicine (20th edition.) Chapter 349, Page 2517

24. SYSTEMIC SCLEROSIS
 Disorder with multisystem involvement and
heterogeneous clinical manifestations
 Chronic course with a strong female predominance
(4.6:1)
 Distinguishing clinical hallmark- Scleroderma(Thickened
skin)
 Overtime fibrosis affects vascular beds and multiple
visceral organs

25. Clinical types of systemic sclerosis
Source: Kasper, D. L., Fauci, A. S., Hauser,
S. L., Longo, D. L. 1., Jameson, J. L., &
Loscalzo, J. (2018). Harrison's principles of
internal medicine (20th edition.); Chapter
353, Pg 2547

26. Diagnostic criteria for systemic sclerosis
Source: Kelley’s and Firestein’s
textbook of rheumatology 10th
edition; Chapter 84; Page 1427

27. Sjogren’s Syndrome
 Chronic, slowly progressive autoimmune disease
 Characterized by lymphocytic infiltration of the exocrine
glands resulting in xerostomia and dry eyes
 Middle-aged women (female-to-male ratio, 9:1) are
primarily
affected

28. Revised International classification criteria for Sjogren’s
syndrome
Source: Firestein, G. S., & Kelley, W. N. (2017). Kelley's
textbook of rheumatology, 10th edition; Chapter 84; Page 1427
ANY 4 out of 6 with either HPE
or serology being positive

29. Dermatomyositis and Polymyositis
 Group of inflammatory myopathies
 Myositis associated antibodies
1. Anti-PM-Scl 75- Polymyositis
2. Anti Mi2 - Dermatomyositis
 Myositis specific antibodies
1. Anti-synthetase autoantibodies- Polymyositis
2. Anti-helicase protein- Dermatomyositis
3. Anti-CADM- Dermatomyositis
4. Anti TTf1γ- Juvenile Dermatomyositis

30. Mixed Connective Tissue Disorder
 Prototypical overlap disease with features of lupus, rheumatoid
arthritis, scleroderma and inflammatory myositis
 Auto-antibodies associated
1. Anti U1-nRNP, U2-nRNP, U3-nRNP
2. Anti single stranded DNA

31. Antibody testing in
Connective Tissue
Disorders

32. Anti Nuclear Antibodies
 Autoantibodies to various nuclear antigens
 First formal description was in the bone marrow of an SLE patient- LE
cell
 Was later found to be attributed to Anti DNA antibody
 In 1951, Indirect immunofluorescence method was used for the very
first time to detect ANA

33. Methods of ANA testing
 Indirect Immunofluorescence
 Enzyme Linked Immunosorbent Assay
 Immunoblotting- EUROIMMUN
 Counter Immuno-electrophoresis- used for detecting extractable nuclear antigens like
anti-Sm, anti-SSA, anti-SSB
 Dot blot Assay- Qualitative
 Flowcytometry- Quantitative
 Multiplex Immunoassay

34. Advantages Disadvantages

35. Advantages Disadvantages

36. Significance of a positive ANA
Souce: Kumar Y, Bhatia A, Minz RW. Antinuclear antibodies and their
detection methods in diagnosis of connective tissue diseases: a
journey revisited. Diagnostic pathology. 2009 Dec;4(1):1.

37. ELISA for ANA
 The ELISA is an immunometric method for detecting and measuring
specific antibodies.
 Highly sensitive and rapid techniques
 Components: A substrate in which an antigen is fixed (typically a 96-well
microwell plate), the patient’s sera, washing solutions, and a detection
method in which an enzyme is linked to an antibody that detects the
antigen

38.  Newer Methods of ELISA
1. Capture ELISA
2. Probe ELISA
 These methods have increased sensitivity and specificity
ELISA for ANA

39. Immunofluorescence Technique
 The gold standard screening test for ANA
 In vitro determination of auto antibodies(IgG, IgM and IgA) in serum or plasma
 Method – Indirect Immunoflourescence
 Substrate used - Hep-20-10 cell line and primate liver
Substrate
incubated
with 25 µl of
diluted
patient’s
serum
(1:100
dilution)
If positive-
Antibodies
IgA, IgM, IgG
attach to
the
correspondi
ngnuclear
antigen
The attached
antibodies
are stained
with
fluorescein
labelled anti
human
antibodies
Examine
under
fluorescence
microscope

40. Interpretation of IF results

41. ANA - Negative
NO Fluorescence

42. Nuclear homogenous or Diffuse
 Antigen association:
dsDNA, nucleosomes, histones
 Diseases associated :
1. SLE
Drug induced lupus
2. Juvenile idiopathic arthritis

43. Nuclear Dense Fine Speckled
 Antigen association:
DFS70 ( DenseFineSpeckled70)
 Diseases associated :
 Systemic sclerosis
 SLE

44. Nuclear Fine speckled
 Antigen association:
 SS-A/Ro
 SS-B/La
 Mi-2
 Diseases associated :
 Sjogren’s Syndrome
 Steven Johnson Syndrome
 SLE
 Dermatomyositis

45. Nuclear large coarse speckled
 Antigen association:
 hnRNP
 U1RNP
 Sm
 RNA polymerase III
 Diseases associated :
 Mixed Connective Tissue disease
 SLE
 Systemic Sclerosis

46. Multiple Nuclear Dots
 Antigen association:
 Sp-100
 PML(Pro Myelocytic Leukemia)Bodies
 Diseases associated :
 Primary Biliary Cirrhosis
 SARD(Systemic Autoimmune Rheumatic
Diseases)
 Dermatomyositis

47. Few nuclear Dots(1-6 dots)
 Antigen association:
 p80-coilin
 SMN( Survival Motor Neuron)
 Diseases associated :
 Asymptomatic individuals
 SLE
 SSc
 PM

48. Nuclear Envelope
Smooth
Antigen Associated:
Lamins A,B,C,
Antigen
Associated:Nuclear pore
complex proteins
Disease Associated:
SLE
SjS
Seronegative arthritis
Disease Associated:
Primary Biliary
Cholangitis
Punctate

49. Nucleolar
Homogenous Clumpy Punctate
Antigen associated:
PM/Scl-75
PM/Scl-100
Antigen Associated:
U3-snoRNP/fibrillarin
Antigen Associated:
RNA polymerase I
hUBF/NOR-90
Disease Associated: Systemic
Sclerosis

50. Nuclear Centromeric
Antigen association:
CENP- A and CENP-B
( Centromere protein A and
B)
Diseases associated :
Limited cutaneous
Systemic sclerosis
Primary Biliary cholangitis

51. DNA Topoisomerase I like pattern
Comprises of:
1. Consistent strong fine speckled staining of
condensed chromatin in mitotic cells
2. Strong staining of nucleolar organizing
region (NOR)
3. Weak cytoplasmic staining
4. Variable nucleolar staining or peri-
nucleolar staining.
Disease associated: Diffuse
cutaneous Systemic sclerosis

52. Limited
Cutaneous
SSc
Diffuse
Cutaneous
SSc
CENTROMERE
PROTEINS
TOPO-
ISOMERASE I
PM/SCL RNA
POLYMERASE
III
U3 RNP(
FIBRILLARIN)
Nuclear
coarse
speckle
d
Nucleola
r clumpy
Topo I
pattern
Centro
meric
Nucleola
r clumpy

53. Quick summary of the patterns

54. Immunoline Assay- ANA profile
 Indication: Positive ANA by Immunoflourescence method.
 A qualitative ELISA based in vitro assay for IgG, IgA and IgM
autoantibodies.
Test Strips coated
with parallel lines of
purified antigens are
placed in the empty
channel
Each channel is
filled with 1.5 ml
of sample buffer
Incubate for
5 min at
room temp
on a rocking
shaker
Add 1.5 ml of
diluted serum
sample(1:100)
and incubate for
30 mins at room
temp on a
rocking shaker
Aspirate off the
excess liquid and
wash 3 times with
1.5 ml of buffer
Add 1.5 ml
diluted
enzyme
conjugate
and
incubate for
30 mins
Add 1.5 ml of
substrate
solution and
incubate for
10 min at
room temp
Aspirate off the
liquid and wash
3 times with
1.5ml distilled
water
EVALUATE

55. • Quantitative evaluation of 14 different Nuclear Antigens can be
performed
• Analysis of the strips is automated and done using EUROLineScan
programme
• Interpretation:
An intense dark band at the line of the corresponding antigen appears
if the serum sample contains specific antibodies.
This is interpreted by the software programme and displayed as a
positive result
Immunoline Assay- ANA profile

57. Interpretation of intensity of positivity by clinicians:
• For clinical diagnosis, the clinical symptoms and further findings should always
be taken into account alongside the serological result
• A negative serological result DOES NOT exclude the presence of disease

58. Upcoming methods for ANA testing
ANTIGEN MICROARRAY:
 A nanotechnology technique
 Pre-synthesized antigens are printed on polystyrene and incubated with serum
samples
 Then horseradish peroxidase-conjugated secondary antibodies and
chemiluminescent substrates are added
 Result: Light signals produced are captured by a charge-coupled device
camera based chip reader.
 Antibodies are quantified by use of calibration curves

59. Advantages:
 complete automation
 consistent performance
 cost-effectiveness
 More precise measurement of antibody levels

61. ANCA ASSOCIATED VASCULITIS
• Group of small vessel vasculitis(small intraparenchymal arteries,
arterioles,
capillaries, and venules)
• Characterized by necrotizing vasculitis with few or no immune
deposits
• Another common feature- Necrotizing crescentric glomerulonephritis
with no or very few immune deposits

63. Granulomatosis with polyangiitis
 Previously known as Wegener’s granulomatosis.
 Characterized by involvement of the upper and lower respiratory
tracts together with glomerulonephritis
 The histopathologic hallmarks are necrotizing vasculitis of small
arteries and veins with granuloma formation(either intravascular or
extravascular)
 Male to female ratio is 1:1

64. Churg Strauss Syndrome(EGPA)
 Characterized by Asthma, peripheral and tissue eosinophilia, extravascular and vascular
granuloma formation
 Clinically presents as severe asthmatic attacks with pulmonary infiltrates.
 Mononeuritis multiplex is the second most common manifestation to (72% of patients)
 Allergic rhinitis and sinusitis (61% of patients) is an early symptom

65. Microscopic polyangiitis
 Necrotizing vasculitis with few or no immune complexes affecting
small vessels
 Glomerulonephritis is very common and pulmonary capillaritis often
occurs
 Present with features similar to Wegener’s
 However, the vasculitis is not characterized by granuloma formation
 The diagnosis is based on histologic evidence of vasculitis or pauci
immune glomerulonephritis in a patient with compatible clinical
features of multisystem disease.

66. Diagnostic Criteria for GPA(ACR criteria)
1.Abnormal urinary sediment (red blood cell casts or >5 red blood cells/high-power field)
2. Abnormal findings on a chest radiograph (e.g.nodules, cavities, or fixed infiltrates)
3. Oral ulcers or nasal discharge
4. Biopsy findings of granulomatous inflammation
2 OR MORE OUT OF 4
Source: Firestein, G. S., & Kelley, W. N.
(2017). Kelley's textbook of rheumatology,
10th edition; chapter 89; Page 1541

67. Diagnostic Criteria for EGPA(ACR criteria)
1.Asthma
2. Eosinophilia greater than 10% on white blood cell
count differential
3. Mononeuropathy (including multiplex) or polyneuropathy
4. Non fixed pulmonary infiltrates on a chest
radiograph
5. Paranasal sinus abnormality
6. A biopsy specimen containing a blood vessel with extravascular eosinophils
4 OR MORE OUT OF 6 Source: Firestein, G. S., & Kelley, W. N.
(2017). Kelley's textbook of rheumatolo
10th edition; chapter 89; Page 1541

68. Diagnosis of ANCA associated vasculitis
 The roles of laboratory tests and biopsy vary with the clinical setting
 The presence of positive ANCA does NOT establish the diagnosis of AAV
 Biopsy should be performed to establish the diagnosis along with
clinical manifestations

69. Role of ANCA in diagnosis of vasculitis
 At present there are no validated diagnostic criteria for ANCA
associated vasculitis.
 ANCA detection was included as part of a consensus methodology
developed in 2007
 The combined potential pathogenic role of these autoantibodies and
the good test performances of the ANCA-assays, formed the basis for
incorporating ANCAs into nomenclature criteria

70. ANCA is diagnostic of AAV in these settings
Firestein, G. S., & Kelley, W. N. (2017). Kelley's textbook
of rheumatology, 10th edition, Chap 89; Pg 1542

71. Anti Neutrophil Cytoplasmic Antibody
 Initially discovered in 1959 in patients with chronic inflammatory disorders
 Its association with vasculitis was discovered in 1982.
 Antibodies directed against certain proteins in the cytoplasmic granules of neutrophils
and monocytes.
 These autoantibodies are present in a high percentage of patients with certain types of
vasculitis.
 There are two major categories of ANCA based on different targets for the antibodies:
- MPO ANCA
- PR3 ANCA

72. PR3- ANCA MPO-ANCA
TARGET ANTIGEN Proteinase 3
(Serine protease
present in
neutrophil
azurophilic
granules)
Myeloperoxidase
Others: Elastase,
cathepsin G,
lactoferrin,
lysozyme, and
bactericidal/
permeability-
increasing protein
IF PATTERN Granular
cytoplasmic
staining
Perinuclear staining
ASSOCIATED
VASCULITIS
Granulomatosis
with poly angiitis
Microscopic
polyangiitis and
Churg Strauss
syndrome

76. Methods of laboratory testing of ANCA
 Indirect immunofluorescence
 Enzyme linked immunoassay
 Fluorescent-enzyme immunoassays
 Chemiluminescent immunoassays

77. Indirect Immunofluorescence for ANCA
 A screening test for ANCA
 In vitro determination of auto antibodies(IgG, IgM and IgA) in serum or plasma
 Method – Indirect Immunoflourescence
 Substrate used - Ethanol fixed granulocytes, Formalin fixed granulocytes, Hep-2 cells+
ethanol fixed granulocytes

78. C-ANCA
Classic granular
cytoplasmic
fluorescence with
central or
interlobular
accentuation.
Ethanol fixed Formalin fixed
Diseases associated
Granulomatosis with
polyangiitis

79. Ethanol fixed Formalin fixed
P-ANCA
Perinuclear
fluorescence,
with or without
nuclear
extension
Diseases associated: EGPA
MPA
IBD

80. Atypical C- ANCA
Ethanol Fixed Formalin Fixed

81. ATYPICAL pANCA
Diseases:
SLE
Rhematoid arthritis
PSC
Autoimmune hepatitis
Ethanol Fixed Formalin fixed

82. In Conclusion
 Role of pathologists in auto immune diseases lies in accurate interpretation and reporting
of autoantibody tests which
1. Helps the clinician make an accurate and confirmatory diagnosis of patients presenting
with classical symptoms
2. Helps in narrowing down differential diagnoses when clinical presentation is atypical( a
negative ANA makes SLE unlikely)
3. Predicts particular organ involvement before it occurs as in SLE( anti dsDNA and anti SSA)
4. Predicts disease severity as in Anti CCP in Rheumatoid arthritis
Overall outcome of the above being a better and more holistic approach to patient care.

83. References
 Firestein, G. S., & Kelley, W. N. (2017). Kelley's textbook of rheumatology, 10th edition
 Kasper, D. L., Fauci, A. S., Hauser, S. L., Longo, D. L. 1., Jameson, J. L., & Loscalzo, J.
(2018) Harrison's principles of internal medicine (20th edition.)
 Bossuyt X, Tervaert JW, Arimura Y, Blockmans D, Flores-Suárez LF, Guillevin L, Hellmich
B, Jayne D, Jennette JC, Kallenberg CG, Moiseev S. Position paper: Revised 2017
international consensus on testing of ANCAs in granulomatosis with polyangiitis and
microscopic polyangiitis. Nature Reviews Rheumatology. 2017 Nov;13(11):683.
 Kumar Y, Bhatia A, Minz RW. Antinuclear antibodies and their detection methods in
diagnosis of connective tissue diseases: a journey revisited. Diagnostic pathology. 2009
Dec;4(1):1.

84. References
 Rowley M, Whittingham S. The role of pathogenic autoantibodies in
autoimmunity. Antibodies. 2015 Nov 10;4(4):314-53.
 Castro C, Gourley M. Diagnostic testing and interpretation of tests for
autoimmunity. Journal of Allergy and Clinical Immunology. 2010 Feb
1;125(2):S238-47.
 Joshi V, Rao A. Approach to ANCA Interpretation.
 Lin MW, Silvestrini RA, Culican S, Campbell D, Fulcher DA. A dual-fixed
neutrophil substrate improves interpretation of antineutrophil cytoplasmic
antibodies by indirect immunofluorescence. American journal of clinical
pathology. 2014 Sep 1;142(3):325-30.

85. THANK YOU