DOCK8

We aimed to describe the clinical, immunological, and genetic features of patients with DOCK8 deficiency (DOCK8-Def) in a tertiary care center for children.

Retrospective chart review of patients' clinical, immunological, and genetic characteristics with DOCK8-Def. Genetic analysis was performed with targeted- or whole-exome sequencing; we also assessed DOCK8 protein expression and a lymphoproliferation assay and analyzed survival by the Kaplan-Meier method.

We described 11 patients from 8 unrelated kindreds. The median age at symptoms' onset was 10 months (range 1-54 months). The median follow-up time was 53.4 months (4.8-118.8). All patients presented eczema and recurrent sinopulmonary and cutaneous infections. Besides those symptoms, the most frequent manifestations were bronchiectases (8/11), food allergies (6/11), and severe infections (6/11). Infrequent characteristics were detection of CMV in bronchial lavage, C. parvum-driven sclerosing cholangitis, Takayasu vasculitis, neurological syndromes, pulmonary tuberculosis, and lymphomatoid granulomatosis.

DOCK8-Def has a broad spectrum of manifestations, including allergy, autoimmunity, inflammation, infection, and cancer. The hallmark of this inborn error of immunity is IEI-associated eczema with eosinophilia and increased IgE. Here, we report six new mutations causing human DOCK8 deficiency and symptoms previously unrecognized to occur in DOCK8-Def. Therefore, an early diagnosis of DOCK8-Def is essential to facilitate an adequate treatment such as HSCT.

DOCK8-deficient patients have severe eczema, elevated IgE and eosinophilia, features of Atopic Dermatitis (AD).

To understand the mechanisms of eczema in DOCK8 deficiency.

Skin biopsies were characterized for histology, immuno-fluorescence microscopy, and gene expression. Skin barrier function was measured by trans-epidermal water loss. Allergic skin inflammation was elicited in mice by epicutaneous (EC) sensitization with ovalbumin (OVA) or cutaneous application of S. aureus.

Skin lesions of DOCK8-deficient patients exhibited type-2 inflammation and the patients' skin was colonized by S. aureus, like in AD. Unlike in AD, DOCK8-deficient patients had a reduced FOXP3:CD4 ratio in their skin lesions, and their skin barrier function was intrinsically intact. Dock8^-/- mice exhibited reduced numbers of cutaneous T regulatory cells (Tregs) and a normal skin barrier. Dock8^-/- mice and mice with an inducible Dock8 deletion in Tregs exhibited increased allergic skin inflammation following EC sensitization with OVA. DOCK8 was shown to be important for Treg stability at sites of allergic inflammation and for the generation, survival, and suppressive activity of inducible Tregs (iTregs). Adoptive transfer of wild-type, but not DOCK8-deficient, OVA-specific iTregs suppressed allergic inflammation in OVA-sensitized skin of Dock8^-/- mice. These mice developed severe allergic skin inflammation and elevated serum IgE levels following topical exposure to S. aureus. Both were attenuated following adoptive transfer of WT but not DOCK8 deficient Tregs CONCLUSION: Treg cell dysfunction increases susceptibility to allergic skin inflammation in DOCK8 deficiency and synergizes with cutaneous exposure to S. aureus to drive eczema in DOCK8 deficiency.

There have been exceedingly few reports of epidermodysplasia verruciformis (EV) or EV-like lesions in the vulva. We describe the first observation of vulvar lesions displaying synchronous EV-like histology and conventional high-grade squamous intraepithelial lesion (HSIL), a finding hitherto unreported in medical literature.

To describe this novel vulvar lesion with hybrid features of HSIL and EV, attempt to confirm the hypothesis of coinfection with α and β human papillomavirus (α-HPV and β-HPV) genotypes, and describe relevant underlying genetic mutations.

Cases were retrospectively selected from our institutional archive. Detailed review of clinical information, histologic examination, and whole genome sequencing (WGS) were performed.

Five samples from 4 different patients were included. Three of 4 patients had a history of either iatrogenic immune suppression or prior immune deficiency, and all 3 featured classic HSIL and EV changes within the same lesion. One patient had no history of immune disorders, presented with EV-like changes and multinucleated atypia of the vulva, and was the sole patient without conventional HSIL. By WGS, several uniquely mappable reads pointed toward infection with multiple HPV genotypes, including both α-HPVs and β-HPVs. Mutations in genes implicated in cell-mediated immunity, such as DOCK8, CARMIL2, MST1, and others, were also found.

We provide the first description of vulvar lesions harboring simultaneous HSIL and EV features in the English-language literature, a phenomenon explained by coinfection with α-HPV and β-HPV genotypes. The finding of EV-like changes in a vulvar specimen should prompt assessment of the patient's immune status.