The skin microbiome in X-linked recessive ichthyosis and autosomal recessive congenital ichthyosis

Recruitment & Eligibility

Status: Pending

Sex: Not specified

Target Recruitment: 80

Inclusion Criteria

Patient group:
Patients >= 16 years old with a clinically and via Sanger, molecular inversion
probes and/or whole exome sequencing genetically confirmed form of:
- X-linked recessive ichthyosis: with a mutation in or deletion of the STS gene.
- autosomal recessive congenital ichthyosis: with mutations in the ABCA12,
ALOX12B, ALOXE3, CERS3, CYP4F22, LIPN, NIPAL4, PNPLA1, SDR9C7, SLC27A4,
SULT2B1, ST14 or TGM1 gene.

Control groups:
Skin microbiome data from healthy individuals and patients with AD and/or IV >=
18 and <= 65 years old, who gave consent to use their data for future scientific
research.
These subjects were already recruited in another study approved by the CMO
region Arnhem-Nijmegen (registration number NL41569.091.12). Dr. P.L.J.M.
Zeeuwen, who is part of our research team, was one of the principal
investigators. This previous study compared skin microbiome data between
healthy individuals, atopic dermatitis and ichthyosis vulgaris (published in
Zeeuwen et al., 2016). The goal of our current study is in line with the
consent given by these subjects, as we will use these data to compare to the
obtained skin microbiome data from our patients with X-linked recessive
ichthyosis and autosomal recessive congenital ichthyosis.

Exclusion Criteria

- Body Mass Index greater than or equal to 35 or less than or equal to 18.
- Use of any of the following drugs within the last 6 months:
o systemic antibiotics (intravenous, intramuscular, or oral);
o oral, intravenous, intramuscular, nasal or inhaled corticosteroids;
o cytokines;
o methotrexate or immunosuppressive cytotoxic agents;
o large doses of commercial probiotics consumed (greater than or equal to 108
CFU or organisms per day) - includes tablets, capsules, lozenges, chewing gum
or powders in which probiotic is a primary component. Ordinary dietary
components such as fermented beverages/milks, yogurts, foods do not apply.
- Use of topical antibiotics, antifungal or topical steroids within the
previous 7 days.
- Any confirmed or suspected condition/state of immunosuppression or
immunodeficiency (primary or acquired) including HIV infection
- History of active uncontrolled gastrointestinal disorders or diseases
including:
o inflammatory bowel disease (IBD) including ulcerative colitis
(mild-moderate-severe), Crohn's disease (mild-moderate-severe), or
indeterminate colitis;
o irritable bowel syndrome (IBS) (moderate-severe);
o persistent, infectious gastroenteritis, colitis or gastritis, persistent or
chronic diarrhea of unknown etiology, Clostridium difficile infection
(recurrent) or Helicobacter pylori infection (untreated);
o chronic constipation.
- Female who is pregnant or lactating.

Study & Design

Study Type: Observational non invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The main endpoint will be to create an overview of the relative presence of the<br /><br>different bacterial genera in affected and non-affected skin of patients with<br /><br>XRI and ARCI.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>The secondary parameters are:<br /><br>1) Overview of the different bacterial genera in XRI and ARCI, and in different<br /><br>clinical phenotypes of ARCI.<br /><br><br /><br>(2) Skin microbiota composition of XRI and ARCI patients compared with healthy<br /><br>individuals and patients with AE and/or IV.<br /><br><br /><br>(3) Identification and isolation of specific clinical XRI and ARCI bacterial<br /><br>species for future follow-up studies regarding the pathogenesis of ichthyosis.</p><br>