1. Skin signs of primary immunodeficiencies – how to find the genes to check
Monika Ettinger*, Julia Schreml**, Kornelia Wirsching***,
Mark Berneburg*, Stephan Schreml*
* Department of Dermatology, University Clinic Regensburg
** Institute of Human Genetics, University Hospital of Cologne
*** Department of Otorhinolaryngology, University Medical Center, Regensburg

2. Monika Ettinger, M.D., Ph.D.

3. Introduction What’s already known?
Primary immunodeficiencies (PIDs) are a heterogeneous group of rare diseases (4:100,000)
Due to defects in immune system development and/or function
Increase susceptibility to infection
About 50% have cutaneous manifestations
Allergic or atopic skin manifestations- very common and often severe

4. Diagnostic criteria Suspect PIDs if: ≥ 8 new ear infections in 1 year
≥ 2 serious sinus infections in 1 year
≥ 2 months on antibiotics with little effect
≥ 2 pneumonias in 1 year
Failure of an infant to gain weight or grow normally
Recurrent, deep skin or organ abscesses
Persistent thrush in mouth or elsewhere on skin after age 1
Intravenous antibiotics required to clear infections
≥ 2 deep seated infections
Family history of PIDs

5. Introduction >300 genetically distinct diseases
Classify according to pathogenesis
International Union of Immunological Sciences: 9 major categories

6. Objective
To provide a diagnostic framework for suspected PIDs based on cutaneous signs

7. Example: IL-10 receptor deficiency
Psoriasis- or eczema-like skin lesions
Hair anomalies (hypertrichosis)
Abscesses

8. Framework- how to find genes to check
Cutaneous manifestation
Primary immunodeficiencies
(PID)
Gene
Laboratory work up
Hair anomaly
(Silvery hair)
Chediak-Higashi-Syndrome
 photophobia, nystagmus
LYST
Neutropenia, hypergammaglobulinemia, peroxidise positive giant inclusion bodies in neutrophils
(Bamboo hair)
Comel-Netherton-SyndromTrichorrhexisinvaginata
SPINK5
High serum IgE levels, eosinophilia, hypercomplementemia, NK cell lymphocytopenia
(Silvery grey hair)
Griscelli-syndrome type 2
RAB27A
Mild neutropenia
(Folliculitis)
IL-10-defects
IL10, IL10RA/B
Elevated inflammatory markers, leukocytosis
(White hair)
Hermansky Pudlak syndrome type 2
AP3B1
Pronounced neutropenia and thrombocytopenia

9. Framework- how to find genes to check
Cutaneous manifestation
Primary immunodeficiencies
(PID)
Gene
Laboratory work up
Psoriasis-like skin lesion
IL10R-defects
IL10RA/B
Elevated inflammatory markers, leukocytosis
ICF-syndrome = immunodeficiency, centromer-instability and facial anomaly
DNMT38, ZBTB24
Serum levels of IgG, IgM, IgE, and/or IgA are low
LIG4-syndrome
LIG4
Nijmegen breakage Syndrome
NBS1
Low serum levels of IgG, IgA, lymphopenia
SCID with microcephaly, growth retardation and sensitivity to radiation
NHEJ1

10. IL-10/IL-10 R defect
Psoriasis/eczema-like skin lesions, hair anomaly, abscesses
Check table – based on solitary or combined skin manifestations
Laboratory investigations (basic and specific)
Gene analysis: IL-10/IL-10 R defect
1.  Mutations in IL-10 and IL-10 receptor have been reported in patients with inflammatory bowel disease. 
2.  Patients have severe early onset inflammatory bowel disease during the first year of life.  
3.  Complications include anal fissures and fistulae as well as abscess formation.  Patients commonly require surgical interventions including partial or total colectomy. 
4.  Inflammation is typically unresponsive to immunosuppressive therapies (corticosteroids, methotrexate, anti-TNFalpha).
5.  IL-10 is a critical anti-inflammatory cytokine secreted by immune cells, epithelial cells, and keratinocytes.  IL-10 acts to limit secretion of pro-inflammatory cytokines including TNF-alpha, IL-1, IL-6, and IL-12. 
6.  IL-10 and IL-10 receptor gene sequencing can confirm the diagnosis. 
7.  Hematopoietic stem cell transplantation (HSCT) has been successful in a small number of patients with IL-10 and IL-10 receptor deficiency.   
 OVERVIEW
      IL-10 is a critical anti-inflammatory cytokine secreted by immune cells (monocytes, macrophages, dendritic cells, T cells, and B cells), epithelial cells, keratinocytes, and mast cells.  IL-10 acts to limit secretion of pro-inflammatory cytokines including TNF-alpha, IL-1, IL-6, and IL-12.  The inhibition of pro-inflammatory cytokines prevents excessive immune responses that result in tissue damage.  
     Mutations in IL-10 and IL-10 receptor have been reported in patients with severe early onset intractable inflammatory bowel disease.  Biopsies reveal inflammatory infiltrates, ulcerations and abscesses.   Complications include anal fissures and fistulae as well as abscess formation.  Patients commonly require surgical interventions including partial or total colectomy. 
     The differential diagnosis for early onset enteropathy also includes Wiskott-Aldrich Syndrome (WAS), chronic granulomatous diasease, NEMO deficiency, XIAP deficiency, IPEX syndrome, CD25 deficiency, STAT1 (gain of function) mutations, omen syndrome, and dyskeratosis congenita.  
EVALUATION
Step 1:  Immune Evaluation
-CBC with Differential -IgG, IgM, IgA, IgE -Specific antibody responses to vaccine antigens -Lymphocyte flow cytometry (including naïve/memory T cells) -DHR assay
-A CBC with differential can help screen for Wiskott-Aldrich Syndrome (WAS) (thrombocytopenia and small platelet size).  Patients with Omenn, WAS, IPEX can have eosinophilia.  
-IgG, IgA, IgM, IgE levels are typically normal in patients with IL-10/IL-10R deficiency. Elevated IgE can be present in Omenn syndrome, WAS and IPEX. 
-Specific antibody responses can be reduced in WAS, NEMO deficiency. 
-T cell lymphocytopenia can be present in WAS, CD25 deficiency.  Patients with dyskeratosis congenita typically have a T+B-NK- phenotype.  Patients with Omenn syndrome can have normal or elevated T cells (due to oligoclonal expansion) but the T cells have a memory (CD45RO) phenotype rather than a naïve (CD45RA) phenotype. 
-A DHR assay is an excellent screen for chronic granulomatous disease. 
Step 2:  IL-10R Functional Screen
-A functional screen for IL-10R can be performed by stimulation with IL-10 followed by measurement of STAT3 phosphorylation.  
-This test is commercially available through Seattle Children’s Immunology Diagnostic Laboratory
Step 3:  IL-10R Gene Sequencing -IL-10R gene sequencing (IL10RA/IL10RB) -Genetic testing for IL10RA and IL10RB mutations is commercially available through Seattle Children’s Immunology Diagnostic Laboratory
 MANAGEMENT
           Patients with IL10 and IL10R gene mutations are unresponsive to immunosuppressive therapies (corticosteroids, methotrexate, anti-TNFalpha). Hematopoietic stem cell transplantation (HSCT) has been successful in a small number of patients with IL-10 and IL-10 receptor deficiency, suggesting this may be a viable treatment options for patients with refractory disease.    
OMIM
OMIM
AR, 11q23.3
AR, 21q22.11
IL10RA
IL10RB

11. Laboratory tests for PID
Part of the immune system
Basic lab work
Specific lab work
B-cells/antibodies
meaurement of immunoglobulin levels
(IgG, IgA, IgM)
- measurement of specific antibodies upon immunization with vaccines with protein antigens (tetanus, diphteria) and/or carbohydrate antigens (Pneumovax, HiB) prior and four weeks after immunization, flow cytometry (B- cells)
- immunoglobulin production by cultured
lymphocytes
- genetics
T-cells
- Complete blood count (CBC)
- total blood (absolute)
lymphocyte count (normally
3/4 T-cells)
- response (proliferation, interferon production) of cultured T-cells to stimuli (mitogens: phytohemaglutinin = PHA, antigens: tetanus toxoid, candida antigen)
- Flow cytometry (T-cells)
Neutrophils
- white blood cell counts (WBC)
with differentials
- blood smear (abnormalities in
neutrophil structure)
- oxidative burst measurement (reactive oxygen species production = ROS) via
nitroblue tetrazolium test (NBT) or flow cytometry with dihydrorhodamine 123 (DHR)
Complement system
total hemolytic complement assay (CH50)
- levels of specific complements
- alternate complement pathway test (AH50) and mannan-binding pathway analysis
Innate Immunity
NK-cell counts
- NK-cell activity
- toll-like receptor (TLR) expression

12. Discussion What does this review add?
We provide a framework on how to diagnose a PID and find the genes based on solitary or combined cutaneous manifestations

13. Conclusions PIDs are heterogeneous group of rare diseases
50% associated with cutaneous manifestations
Cutaneous signs can guide the physician in finding the relevant diseases/genes to check for in patients with suspected PIDs

14. Research Team

15. Call for correspondence
Why not join the debate on this article through our correspondence section?
Rapid responses should not exceed 350 words, four references and one figure
Further details can be found here: here