Transcript Immunodeficiency

Paediatrics teaching ppt
Immunodeficiency diseases
Xinhua Hospital
Shanghai Institute for Pediatric Research
Tong-Xin Chen
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 themselves：IgG1(5y)；IgG3(10y)；
IgG2 and IgG4(14y)
 Cord blood IgG level ≥ IgG from mother(>10% of IgG
from mother )
 IgG from mother are catabolized gradually after born
 IgG from mother disappeared completely when 6
months , serum IgG levels of 3~6 months infant are
lowest ，especially IgG2 and IgG4
Development of IgM in Newborn Infant
 IgM from mother can not pass placenta, serum IgM
of fetuses synthesis when born <200-300mg/L
 Normal neonatal IgM increase rapidly after born 47 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
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
Cellular Immunity of Newborn Infant
 Number of T lymphocytes are usually normal
 CD4+T cells are relatively higher，CD4/CD8 up to
3~4，consequently, are susceptible to infections
 Function of Th2 cells are relatively stronger,are
susceptible to allergic diseases
 CD45RA+T cells are more，CD45RO+T cells are
less
 Deficiency of Cytokine ：IFN-γ、IL-4，and so on
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
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
The incidence of PID
 Calculated by alive infants：1/10000
（Japan 1981 and Australia 1983）
 Hongkong report：1/8000
 There is no statistics report in mainland
so far
 According to the incidence of 1/10000，
2500/25000000 nerborn infants every year
in our country，cases add up to 3~8 ten
thousands at least
 More than 100 cases in our hospital since
1970
Clinical features

Recurrent infection

High risk of autoimmune diseases

High risk of malignancy
Infection
 Severe infection、
 Refractory infection 、
 Recurrent infection 、
 Opportunistic pathogens infection 、
 Recurrent diarrhea、
Autoimmunity
diseases
Children with
immunodeficiency have
higher risk of autoimmune
than normal(0.01%~14%)
Immunodeficiency
associated with autoimmune
Autoimmune disease suspicious
X-Linked Agammaglobulinemia
Selective IgA Deficiency
CVID
Thymic hypoplasia
Immunodeficiency with hyperIgM
Chronic granulomatosis
Complement deficiency
Wiskott-Aldrich Syndrome
Arthritis
SLE，JRA
Thrombocytopenia
ITP
Neutropenia
Crohn’s desease
SLE
Hemolytic anemia
Tumor
Children with immunodeficiency
have higher risk of cancer than
normal(100~300 fold)
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
Clinical features
 Growth development deficiency
 Lymph nodes or tonsil deficiency
 Skin changes:capillary vessel expand, petechia
 Skin mildew, lupus erythematosus-like tetter
 Ataxia(A-T)
 Thrush after 1 year old
 Oral ulear
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
 IgG subclasses（1~4）
 Thymus：X -ray
 Cytokine： IL-2，IL2R，IFN，IFNR
 Cell surface molecular：CD18
 Gene analysis：BTK ，CD40L，WASP

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）

X-linked agammaglobulinaemia

Selective IgA deficiency

Thymic hypoplasia

Combined immunodeficiency
 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
Clinical features
 Male
 Onset during 4~6 months of age
 Recurrent Pyogenic bacterial infection
 Respiratorty tract infections are typical，
as well as systemic infections
Immunological characteristics：
 Can hardly produce antibody，all kinds of Ig are
markedly reduced
IgG < 2g/L ( <200mg/dl )
IgA <0.02g/L ( <2mg/dl )
IgM <0.1g/L ( <10mg/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
Alteration of T cell subsets
Alteration of B cell and NK cell
Mutation of Btk gene
cDNA mutation:
62145-62155
Exon10F
989_999delTGA
CTCGGAGTins
GGTGGTATTC
CAAA
Codon change:
MTRS286_289R
WYSK
Mother status:
carrier
62155-62145
Exon10
R
Differential diagnosis ：
Characteristics
Age
IgM
IgG
IgA
XLA
infantile transient
hypogammaglobulinemia
congenital（＞6m）
1~2y
normal
reduced
normal
unclear
presence
no
reduced
absent/ reduced
absent/ reduced
Molecular deficiency BTK
absent/ reduced
B cell
IgG replacement?yes
Common Variable Immunodeficiency （ CVID）
 A heterogeneous group of diseases
characterized by antibody defects
 Late-appearing immunodeficiency
 Immunological characteristics of CVID
• Antibody deficiency IgG <2.5g/L ( <250mg/dl )
IgA usually is reduced
IgM usually is reduced
• Circulating B cells usually are normal or decreased
• Cellular immunity：normal or help function deficiency
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

X-linked agammaglobulinaemia

Selective IgA deficiency

Thymic hypoplasia

Combined immunodeficiency
 Incidence：Caucasian1/500~1500，Japanese1/18500，
Chinese1/5000~10000
 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
 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

X-linked agammaglobulinaemia

Selective IgA deficiency

Thymic hypoplasia

Combined immunodeficiency
 Thymic hypoplasia also is called DiGeorge
syndrome（1964年）
 It is known now that 80%~90% 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
CATCH 22
Cardiac defects
Abnormal facies
Thymus hypoplasia
Cleft palate
Hypocalcemia
Clinical features：
Thymus
hypoplasia
T cell
reduced
Recurrent
infections
（virus
infections ）
Parathyroid
hypoplasia
Hypocalcemia
Tetany
Ⅲ-Ⅳpharyngeal
arch hypoplasia
Cardiac
defects
Tetralogy of Fallot
and aorta abnormal
（eg.arcus aortae
break off）
Ⅰ-Ⅱpharyngeal
arch hypoplasia
Abnormal
facies
Cleft palate 、
short philtrum
and low-set
ears
Laboratory analysis ：
 Number of peripheral blood lymphocytes reduced
（<1000个/mm2）
 CD3+T cell markedly reduced
 Serum Ig normal or reduced，whereas IgE
increased
 Serum calcium reduced ， serum phosphorus
increased ， parathyroidhormone reduced
 Chest radiograph: thymus absence
DiGeorge syndrome:
Boy
14months
Bronchopneumonia
Congenital heart disease
Immunodeficiency
Hypocalcemia
Nearside facial paralysis
Normal Thymus
Thymus shadow of
infant(<6m) is
visible ，
usually>10g
If invisible(< 4g )，
implicated thymus
hypoplasia
DiGeorge syndrome
Thymus absence

X-linked agammaglobulinaemia

Selective IgA deficiency

Thymic hypoplasia

Combined immunodeficiency
 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
Severe combined immunodeficiency （ SCID）
T- B+NK-Ig Approximately 50%~60% 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
T- B-NK+Ig 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
Boy ，8months
Recurrent pneumonia、thrush
One of his uncle died at 6months
unknown cause
T-B+NK-Ig ↓
Figure 8 photo of a patient with SCID : candida albicans
in the mouth
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
Alteration of T cell subsets
Alteration of B cell and NK cell
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
Carrier diagnosis in IL2RG deletion (XSCID) – Patient 1
PCR-agarose gel electrophoresis
Normal
Mother
Patient
-ve control
Normal
Mother
Patient
-ve control
Causative gene: IL2RG in Xchromosome





Primer Pair
Exon 6F/8R
Primer Pair
Exon 5F/8R
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
Hyper IgM syndrome （ HIGM）
T+CD40L-B+IgM↑IgG↓
 Four types，most common type is X-linked
form (Hyper IgM syndrome typeⅠ)
 Approximately 70%，caused by mutations of
the CD40L gene
 Diagnosis: CD40L expression on T cell
reduced in vitro lymphocyte cultivation
T-B cell interaction
IgM
Isotype
switching
B cell
CD40
CD40L
Infections
MHC-Ag
IgG
IgA
IgE
Extracellular
pathogens
IL-2
IFN-γ
Introcellular
pathogens
TCR
cytokine
T cell
CD40L
patient
control
Fig1. CD40 ligand expression induced by PMA+IM in paitent with
HIGM
CD40 ligand gene mutations identified in
11319492-11319495
this study
Exon5
cDNA mutation:
 672-675delCTCA
Codon change:
 L205fsX240
Mother status:
 not carrier
11319495-11319494
Laboratory features of some primary Tcell immunodeficiency
Phenotype
Circulating lymphocyte
Serum Ig
Immunodeficiency
Total number T CD4 CD8 B
SCID
X-linked or JAK3 deficiency
↓
- ↑
RAG-1 or RAG-2 deficiency
↓
- Omenn‘s syndrome
↓
↓ ↓
↓
ADA deficiency
- ZAP-70 deficiency
+
+ +
+
Ⅱnake lymphocyte syndrome
+
+ ↓
+ +
Combined T cell and B cell deficiency
PNP deficiency
↓
- +
Ataxia-telangiectasia
↓
↓ ↓
+ +
Wiskott-Aldrich Syndrome
↓
↓ ↓
↓ +
Selective T cell deficiency
DiGeorge Syndrome
↓
↓ ↓
↓ +
NK IgG IgM IgA
IgE
+
+
+
+
↓
↓
↓
+
±
+
↓
↑
↓
+
+
±
IgG2 ↓
+
±
+
↓
±
↓
↑
↓
↑
+
+
+
+
+
Wiskott Aldrich Syndrome Patient Photo
thrombocytopenic purpura
eczema
Ataxia-telangiectasia Patient Photo
Appearance of this patient
Conjunctiva telangiectasia
Treatment ：
General management
 Strengthen publicizing and nursing，prevent infections
 Antibiotics
 Specific treatment：thrombocyte 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（2000~3000rad）
 Screen CMV strictly in blood productions， avoiding CMV
infections
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）
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 effect:anaphylaxis、blood transmitted
diseases

Enzyme replacement ：
 ADA-PEG：15~30u/ug
subcutaneous injection
1~2/week，
 Washing erythrocytes for PNP、ADA
Cytokine：
 IL-2 for SCID
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
Stem cell transplantation （pure stem cell
CD34+）
 Cord blood stem cell transplantation
 Peripheral blood stem cell transplantation
Thymus transplantation
 <16week fetal thymus transplantation
 Apply to cellular immunity deficiency，
mostly thymic hypoplasia

Gene therapy

Mutant gene
Clone  identify location of mutation

Gene transformation
Target gene fragment
insert
stem cell genome of
patients

Transgenic cell mitosis，
gene transformation fragment replicate
Effect of gene therapy：
ADA
good
PNP
bad
XL-SCID （11cases）
good
MHC II
bad
ZAP70
good
good
good
CGD
bad
XLA
uncertainty
JAK3
LAD
WAS
good