Immunodeficiency diseases

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Immunodeficiency diseases
Paediatrics teaching ppt

• Xinhua Hospital
• Shanghai Institute for Pediatric Research
• Tong-Xin Chen

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Development of Immune System
Development of IgG in Newborn Infant

• Up to normal adults level
• From mother mainly
• Achieve to 60 of adults level when 1 year
  old,and 100 of adults level when 6 years old
• IgG could be subdivided into IgG1?IgG2?IgG3 and
  IgG4
• Age dependent changes of serum IgG level
  synthesized by themselvesIgG1(5y)IgG3(10y)IgG2
  and IgG4(14y)

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• Cord blood IgG level IgG from mother(gt10 of
  IgG from mother )
• IgG from mother are catabolized gradually after
  born
• IgG from mother disappeared completely when 6
  months , serum IgG levels of 36 months infant
  are lowest ,especially IgG2 and IgG4

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Development of IgM in Newborn Infant

• IgM from mother can not pass placenta, serum IgM
  of fetuses synthesis when born lt200-300mg/L
• Normal neonatal IgM increase rapidly after born
  4-7 days,is likely to be associated with the
  response of IgM to intestinal bacteria
• If increasing,implicating neonates are stimulated
  by nonself antigen in uterus

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Development of IgA in Newborn Infant

• Can not pass placenta, serum IgA level achieve to
  20 of adults level when 1 year old,and 100 of
  adults level when 12 years old
• Cord blood IgA level 50mg/L,increasing of IgA
  implicates the possibility of infections in
  uterus
• IgA is detectable in tears and saliva of 2-3
  weeks neonate
• The biological function of IgA is defend against
  some local mucous infections

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Cellular Immunity of Newborn Infant

• Number of T lymphocytes are usually normal
• CD4T cells are relatively higher,CD4/CD8 up to
  34,consequently, are susceptible to infections
• Function of Th2 cells are relatively stronger,are
  susceptible to allergic diseases
• CD45RAT cells are more,CD45ROT cells are less
• Deficiency of Cytokine IFN-??IL-4,and so on

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Immunodeficiency diseases,ID

• A group of disorders characterized by an impaired
  ability to produce normal immune response. Most
  of these disorders are cased by mutations in
  genes involved in the development and function of
  immune organs, cells, and molecules.

• Primary and acquired

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Classification of Primary Immunodeficiency
Diseases(7 main Categories)

• Antibody or B cells deficiency(50)
• Combined immunodeficiency(20)
• Phagocytic dysfunction(18)
• Cellular or T cell deficiency (10)
• Complement deficiency (2)
• Immunodeficiency with other important
  characteristics
• Immunodeficiency with or acquired other
  congenital or hereditary diseases

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The incidence of PID

• Calculated by alive infants1/10000
• (Japan 1981 and Australia 1983)
• Hongkong report1/8000
• There is no statistics report in mainland so far
• According to the incidence of 1/10000,2500/250000
  00 nerborn infants every year in our
  country,cases add up to 38 ten thousands at
  least
• More than 100 cases in our hospital since 1970

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Clinical features

• Recurrent infection
• High risk of autoimmune diseases
• High risk of malignancy

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Infection

• Severe infection?
• Refractory infection ?
• Recurrent infection ?
• Opportunistic pathogens infection ?
• Recurrent diarrhea?

12
Children with immunodeficiency have higher risk
of autoimmune than normal(0.0114)
Autoimmunity diseases
Autoimmune disease suspicious Arthritis SLE,JRA
Thrombocytopenia ITP Neutropenia Crohns
desease SLE Hemolytic anemia
Immunodeficiency associated with autoimmune
X-Linked Agammaglobulinemia Selective IgA
Deficiency CVID Thymic hypoplasia Immunodeficiency
with hyperIgM Chronic granulomatosis Complement
deficiency Wiskott-Aldrich Syndrome
13

• Children with immunodeficiency have higher risk
  of cancer than normal(100300 fold)

Tumor
14
Primary immunodeficiency suspicious
History

• Tympanitis more than 8 times per year
• Severe nose sinusitis more than 2 times per year
• Pneumonia more than 2 times per year
• Deep infection in abnormal position more than 2
  times
• Recurrent infection in deep skin or viscera
• Infection eliminated with antibiotics by
  intravenous injection
• Rare or opportunistic pathogens infection
• Family PID history

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Clinical features

• Growth development deficiency
• Lymph nodes or tonsil deficiency
• Skin changescapillary vessel expand, petechia
• Skin mildew, lupus erythematosus-like tetter
• Ataxia(A-T)
• Thrush after 1 year old
• Oral ulear

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Laboratory analysis

• Serum IgG,IgM,IgA(B cell function)
• CD3,CD4,CD8 (T cell subsets)
• CD19( number of B cell )
• CD56/16( NK cell )
• White blood cell count or nitroblue tetrazolium(
  NBT )test
• Complement

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• IgG subclasses(14)
• ThymusX -ray
• Cytokine IL-2,IL2R,IFN,IFNR
• Cell surface molecularCD18
• Gene analysisBTK ,CD40L,WASP

?
18
Common primary immunodeficiency diseases

• Combined immunodeficiency (14)
• Antibody or B cells deficiency (10)
• Cellular or T cell deficiency (9)
• Immunodeficiency with other important
  characteristics(3)
• Phagocytic dysfunction (12)
• Complement deficiency (16)
• Immunodeficiency with or acquired other
  congenital or hereditary diseases (41)

19

• X-linked agammaglobulinaemia
• Selective IgA deficiency
• Thymic hypoplasia
• Combined immunodeficiency

20

• X-linked agammaglobulinaemia ( XLA )
• Also named as Bruton disease(described in 1952)
• Discovered that the disease was associated with
  mutation of the gene coding pre B-cell
  cytoplasmic tyrosine kinase( btk)in1993
• Mutation lead to block in signal transduction of
  B cell development,block in maturation after the
  pre-B cell stage ,lead to decreaseing of mature
  B cell
• The patterns of mutations are diverse,more than
  118 cases are reported so far

21
Clinical features

• Male
• Onset during 46 months of age
• Recurrent Pyogenic bacterial infection
• Respiratorty tract infections are typical,as well
  as systemic infections

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Immunological characteristics

• Can hardly produce antibody,all kinds of Ig are
  markedly reduced
• IgG lt 2g/L ( lt200mg/dl )
• IgA lt0.02g/L ( lt2mg/dl )
• IgM lt0.1g/L ( lt10mg/dl )
• Circulating B cells are markedly
  decreased,usually less than 0.5 of total
  lymphocytes
• Numbers and function of T lymphocytes are normal
• Btk gene located on Xq21.3-22 is deficiency

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Alteration of T cell subsets
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Alteration of B cell and NK cell
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Mutation of Btk gene
62145-62155
cDNA mutation 989_999delTGACTCGGAGTinsGGTGGTATTCC
AAA Codon change MTRS286_289RWYSK Mother
status carrier
Exon10F
62155-62145
Exon10R
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Differential diagnosis
infantile transient hypogammaglobulinemia 12y no
rmal reduced normal unclear presence no
Characteristics Age IgM IgG IgA Molecular
deficiency B cell IgG replacement?
XLA congenital(gt6m) reduced absent/
reduced absent/ reduced BTK absent/ reduced yes
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Common Variable Immunodeficiency ( CVID)

• A heterogeneous group of diseases characterized
  by antibody defects
• Late-appearing immunodeficiency
• Immunological characteristics of CVID

• Antibody deficiency IgG lt2.5g/L ( lt250mg/dl )
• IgA usually is
  reduced
• IgM usually is
  reduced
• Circulating B cells usually are normal or
  decreased
• Cellular immunitynormal or help function
  deficiency

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Clinical manifestations

• Recurrent infection ( bacterial infection)with
  onset at any age, affects both males and females
• High risk of gastrointestinal infections,usually
  chronic giardiasis
• Lymphoma and gastric carcinoma occur with
  increased frequency
• Increased incidence of autoimmune
  disease(hemolytic anemia ?pernicious anemia?
  thrombocytopenia,et al)
• lymphoproliferation,splenomegalia,lymphoid
  hyperplasia

29

• X-linked agammaglobulinaemia
• Selective IgA deficiency
• Thymic hypoplasia
• Combined immunodeficiency

30

• IncidenceCaucasian1/5001500,Japanese1/18500,Chin
  ese1/500010000
• Associated with maladjustment of Th2 cell to B
  cell produce IgA
• Both males and females, often coincide in same
  family
• Mild form is asymptomatic
• Recurrent infections in infancy(respiratory
  ?intestinal and urinary infections )
• Be associated with autoimmune diseases?asthma and
  intestinal malabsorption

31

• Serum IgA less than 0.05g/L,IgM?IgG normal or
  increased
• sIgA markedly reduced
• Serum IgA could increase to normal level in some
  cases
• Should not be treated with IVIG,since capable of
  forming anti-IgA antibodys subsequent allergy

32

• X-linked agammaglobulinaemia
• Selective IgA deficiency
• Thymic hypoplasia
• Combined immunodeficiency

33

• Thymic hypoplasia also is called DiGeorge
  syndrome(1964?)
• It is known now that 8090 Digeorge syndrome
  have minor deletion of gene located at 22q11
• Minor deletion of gene located at 22q11 included
  a group of disease,now called CATCH22 syndrome

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CATCH 22
Cardiac defects Abnormal facies Thymus
hypoplasia Cleft palate Hypocalcemia
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Clinical features
Thymus hypoplasia
Parathyroid hypoplasia
?-?pharyngeal arch hypoplasia
?-?pharyngeal arch hypoplasia
Cardiac defects
Abnormal facies
T cell reduced
Hypocalcemia
Recurrent infections(virus infections )
Cleft palate ?short philtrum and low-set ears
Tetralogy of Fallot and aorta abnormal(eg.arcus
aortae break off)
Tetany
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Laboratory analysis

• Number of peripheral blood lymphocytes
  reduced(lt1000?/mm2)
• CD3T cell markedly reduced
• Serum Ig normal or reduced,whereas IgE increased
• Serum calcium reduced , serum phosphorus
  increased , parathyroidhormone reduced
• Chest radiograph thymus absence

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DiGeorge syndrome
Boy 14months Bronchopneumonia Congenital heart
disease Immunodeficiency Hypocalcemia Nearside
facial paralysis
38
Normal Thymus
Thymus shadow of infant(lt6m) is visible
,usuallygt10g If invisible(lt 4g ),implicated
thymus hypoplasia
39
DiGeorge syndrome Thymus absence
40

• X-linked agammaglobulinaemia
• Selective IgA deficiency
• Thymic hypoplasia
• Combined immunodeficiency

41

• A group of diseases,occurs both males and females
  in autosomal recessive SCID,only males in
  X-linked recessive SCID
• Recurrent infections with fungi, bacteria, virus,
  mycobacterium, protozoa
• Typical features chronic diarrhea?pneumonia and
  persistent fungal infections (especially thrush)
• Sometimes morbilliform rash is the only symptom
  of SCID in neonatal period ,may caused by GVHR
• Usually succumb to overwhelming infection whithin
  the first year of life

42
Severe combined immunodeficiency ( SCID) T-
BNK-Ig-

• Approximately 5060 SCID are X-linked forms
  ,the most common genetics alteration is mutation
  of receptor ?c of IL-2?IL-4?IL-7?IL-9 and IL-15
• Autosomal recessive SCID usually have JAK3 gene
  deficiency,JAK3 coded a tyrosine protein kinase
  which is associated with signal transduction
  initiated by ?c

43
T- B-NKIg-

• Autosomal recessive SCID may have mutations of
  RAG-1 and RAG-2,affects antigen receptor on T?B
  cells surface
• In addition, approximately 50 autosomal
  recessive SCID have adenosine deaminase
  (ADA)deficiency

44
Boy ,8months Recurrent pneumonia?thrush One of
his uncle died at 6months unknown cause T-BNK-Ig
?
Figure 8 photo of a patient with SCID candida
albicans in the mouth
45
Boy ,4.5months Fever ,pneumonia,hepatosplenomegaly
,Have abscess after inoculating BCG vaccine 3
months ,rash and diarrhea after transfusion
Figure 8-2 photo of a patient with SCID GVHD
and BCG vaccination
46
Alteration of T cell subsets
47
Alteration of B cell and NK cell
48
Molecular Diagnosis of X-SCID in Patient 1 IL2RG
gene PCR direct sequencing
487bp deletion

• Deletion mutation from intron 6 to 7 including
  exon 7 and 2 primer site (IVS6-71 to
  IVS7-11del487)
• Predicted frameshift start at arginine 285 with
  stop codon (TAA)created at position 342,
  predicted premature termination (R285fsX342)

?
Patient 1 deletion between Intron 6 and intron 7
?
?
Deletion in patient
Deletion in patient
?
?
IVS6-17
IVS7-11
Normal control Intron 6
Normal control Intron 7
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Carrier diagnosis in IL2RG deletion (XSCID)
Patient 1PCR-agarose gel electrophoresis

• Causative gene IL2RG in X-chromosome
• PCR amplified for each exon for sequencing
• No PCR product for amplification of exon 6, 7 and
  8
• Suspected large deletion, try other primer pairs
  combination
• Deletion mutation including exon 7 and 2 primer
  site found (IVS6-71 to IVS7-11del487)
• Mother diagnosed as heterozygous carrier by PCR
  directly

50
Hyper IgM syndrome ( HIGM)
TCD40L-BIgM?IgG?

• Four types,most common type is X-linked form
  (Hyper IgM syndrome type?)
• Approximately 70,caused by mutations of the
  CD40L gene
• Diagnosis CD40L expression on T cell reduced in
  vitro lymphocyte cultivation

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T-B cell interaction
Infections
IgM
Isotype switching
IgG IgA IgE
Extracellular pathogens
CD40
MHC-Ag
TCR
CD40L
cytokine
IL-2 IFN-?
Introcellular pathogens
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CD40L
patient
control
Fig1. CD40 ligand expression induced by PMAIM in
paitent with HIGM
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CD40 ligand gene mutations identified in this
study
11319492-11319495
Exon5 cDNA mutation ? 672-675delCTCA Codon
change ? L205fsX240 Mother status ?
not carrier
11319495-11319494
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Laboratory features of some primary Tcell
immunodeficiency
Phenotype
Serum Ig
Circulating lymphocyte
Immunodeficiency SCID X-linked or JAK3
deficiency RAG-1 or RAG-2 deficiency Omenns
syndrome ADA deficiency ZAP-70 deficiency
?nake lymphocyte syndrome Combined T cell and B
cell deficiency PNP deficiency
Ataxia-telangiectasia Wiskott-Aldrich
Syndrome Selective T cell deficiency DiGeorge
Syndrome
T - - ? - - ? ? ?
CD4 - - ? - ? - ? ? ?
CD8 - - ? - - - ? ?
B ? - - -
NK - - -
IgG - - - - - ? IgG2 ?
IgM ? - ? - ?
IgA - - - - ? ? ?
IgE - - ? - - ? - ? ?
Total number ? ? ? - ? ? ? ?
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Wiskott Aldrich Syndrome Patient Photo
thrombocytopenic purpura
eczema
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Ataxia-telangiectasia Patient Photo
Conjunctiva telangiectasia
Appearance of this patient
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Treatment
General management

• Strengthen publicizing and nursing,prevent
  infections
• Antibiotics
• Specific treatmentthrombocyte for WAS,calcium
  and Vit D for thymic hypoplasia
• Avoid live vaccines to patients with T cell
  deficiency
• Avoid fresh blood productions transfusion to
  patients with T cell deficiency in case of
  GVHR,if necessary,should be treated by
  ray(20003000rad)
• Screen CMV strictly in blood productions,
  avoiding CMV infections

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Specific treatment to immunodeficiency

• B cell deficiency IVIG
• T cell deficiency Thymic hormones , stem cell
  transplantation
• Phagocytic dysfunction stem cell transplantation
• Complement deficiency Replacement therapy
  plasma
• Gene therapy ADA,SCID (11cases)

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Replacement therapy

• IVIG replacement therapy
• 80 patients have different degree IgG or other
  antibodys deficiency
• 400mg/kg/m
• Serum IgG should be increased more than 5g/L in
  principle
• Side effectanaphylaxis?blood transmitted
  diseases

?
60

• Enzyme replacement
• ADA-PEG1530u/ug 12/week,subcutaneous
  injection
• Washing erythrocytes for PNP?ADA

• Cytokine
• IL-2 for SCID

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Immune reconstitution

• Bone marrow transplantation
• Allogenetic homozygote bone marrow
  transplantation (HLA completely matching)
• Allogenetic hemizygote bone marrow
  transplantation (HLA half matching)
• Unrelated donor bone marrow transplantation

62

• Stem cell transplantation (pure stem cell CD34)
• Cord blood stem cell transplantation
• Peripheral blood stem cell transplantation

• Thymus transplantation
• lt16week fetal thymus transplantation
• Apply to cellular immunity deficiency,mostly
  thymic hypoplasia

?
63
Gene therapy

• Mutant gene
• Clone ? identify location of mutation
• Gene transformation
• Target gene fragment stem cell
  genome of patients
• Transgenic cell mitosis,
• gene transformation fragment replicate

insert
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Effect of gene therapy
PNP MHC II CGD XLA
ADA XL-SCID (11cases)
ZAP70 JAK3 LAD
WAS
bad bad bad uncertainty
good good good good good good
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Thank you!