Clinical, immunological, and genetic characterization of colombian patients with cutaneous recalcitrant warts

Abstract

ABSTRACT: Inborn errors of the immunity (IEI) are monogenic diseases that result in a predisposition to a whole spectrum of infectious diseases. In humans, cutaneous warts are caused by infection with Human Papillomavirus (HPV). Warts are relatively common with an incidence of ~10% in the general population and regress spontaneously. However, warts persisting over two years in some patients despite aggressive treatments with conventional therapies are called cutaneous recalcitrant warts (RW). RW can be present in patients with IEI but also in otherwise healthy individuals. The host defense against HPV relies on functional cellular immunity, including T cells, natural killer (NK) cells, and skin-intrinsic immunity. Therefore, in patients with RW, concern for an immune defect may be considered. Cutaneous RW has been documented in combination with a broad spectrum of infectious diseases in patients IEI such as severe combined immunodeficiency, common variable immunodeficiency, inborn errors of immunity with isolated or syndromic characteristics and NK deficiencies, and with acquired immunodeficiencies such as patients infected with Human Immunodeficiency Virus (HIV) and organ transplant recipient. Also, patients with epidermodysplasia verruciformis (EV) which is characterized by macules like tinea versicolor and Tree Man Syndrome that present manifestations as cutaneous horns presents specific genetic predispositions to b- and a-HPV infection respectively, but only very few are known about genetic susceptibility to RW, and to our knowledge, no studies are searching for monogenic defects associated with RW. Therefore, we hypothesized that susceptibility to cutaneous RW due to HPV in otherwise 6 young healthy individuals might be due to underlying genetic defects in the intrinsic and innate immunity. Aim: To describe the clinical, immunologic characteristics and genetic defects responsible for susceptibility to cutaneous recalcitrant warts (RW) in Colombian patients. Methodology: We conducted a descriptive study. In our cohort, we included otherwise healthy Colombian patients affected with cutaneous RW, negative for HIV infection, and without history of cancer, primary immunodeficiency or acquired immunodeficiency. First, we reviewed medical records, including the history of HPV infection and pharmacological treatments. We obtained pedigrees and collected blood samples and performed immunophenotyping. Finally, Whole Exome Sequencing (WES) was performed in the genomic DNA of several patients and some of their relatives and performed extensive in silico analysis to search for potential candidate genes. Results: We recruited 11 patients with ages between 9 to 34 years old (five males and six females), belonging to 11 families that fulfilled the inclusion criteria. We make the pedigrees for all families. Five patients have a family history of cervix HPV infections. Sequencing by WES was performed for 7 patients and 11 relatives, and after a deep analysis we obtained 7 candidate variants in PYGO2, CASP9, CCNA2, CCNB3, GLTSCR2, PABPC1 and CAD that we postulate can explain the clinical phenotype of RW in these patients. We found no candidate variants in genes that have been previously associated with IEIs in which RW has been described. Likewise, immunophenotyping of peripheral blood was performed in one patient, which was normal in percentages and numbers. Conclusions:

The presence of multiple affected individuals in different generations of the pedigrees, with no sex differences between affected individuals, suggests that susceptibility to cutaneous RW in our patients has a genetic component with an autosomal dominant inheritance pattern. The lack of candidate variants in genes previously associated with inborn errors of the immunity (IEI) in patients with which RW, suggest that our patients probably have a new genetic defect not previously described in the literature. The presence of variants in genes associated by connectome with genes previously associated with IEIs with presence of RW, in addition to the familial history of RW in the kindreds included in our study, supports the hypothesis that susceptibility to RW is the consequence of an IEI not previously described. The clinical characteristics of our cohort of otherwise healthy patients with RW supported by the normal numbers of leukocyte subpopulations in peripheral blood in one patient, in addition to familial history of RW in the kindreds of our cohort suggest that the underlying causes of RW in our patients are caused by deficiencies of components of the immune system that are specific against HPV infection.

RESUMEN: RESUMEN: Objetivo: Describir las características clínicas e inmunológicas y los defectos genéticos responsables de la susceptibilidad a verrugas recalcitrantes cutáneas (VR) en pacientes colombianos. Metodología: Nosotros realizamos un estudio descriptivo. En nuestra cohorte incluimos pacientes colombianos con diagnóstico de VR aparentemente sanos, negativos para infección por VIH y sin historial individual de cáncer. Primero, revisamos las historias clínicas de los pacientes incluyendo el historial de infecciones por VPH y tratamientos farmacológicos. También, obtuvimos los pedigríes de las familias, muestras de sangre y realizamos inmunofenotipificación. Finalmente, realizamos secuenciación completa del exoma (WES) en el ADN genómico de algunos pacientes y algunos de sus familiares y realizamos un análisis in sillico para buscar genes candidatos potenciales. Resultados: Nosotros captamos 11 pacientes con edades entre los 9 y 34 años (cinco hombres y seis mujeres), pertenecientes a 11 familias que cumplieron todos los criterios de inclusión. Cinco pacientes presentan historia familiar de infecciones por VPH cervical. Obtuvimos variantes candidatas de los datos de WES de 7 pacientes y 11 familiares que pueden explicar la relación entre la presencia de VR y un genotipo. Adicionalmente, en 11 uno de los pacientes las subpoblaciones de sangre periférica revelaron porcentajes y conteos normales. Conclusiones: - Las características clínicas de los pacientes, además de la historia familiar de verrugas resistentes a tratamientos y persistentes en el tiempo, así como, la presencia de subpoblaciones generales de leucocitos normales en sangre periférica sugieren que el defecto inmunológico responsable de esta susceptibilidad es especifico de la respuesta contra VPH. - La falta de variantes en genes previamente descritos en los que la susceptibilidad a VR está acompañada de otros fenotipos clínicos sugiere que estos pacientes presentan un defecto inmunológico no previamente descrito. - La presencia de múltiples miembros afectados en diferentes generaciones en los pedigríes, sin predilección de sexo entre los miembros afectados, sugiere que la susceptibilidad especifica a VR en nuestros pacientes presenta un componente genético con un patrón de herencia autosómico dominante. - La presencia de variantes en genes relacionados por conectividad con genes previamente reportados de susceptibilidad a VR acompañada por otros fenotipos clínicos, además de la historia familiar de VR en nuestros pacientes, soporta la hipótesis de que la susceptibilidad a VR es un error innato de la inmunidad no reportado previamente.