Potentially Malignant Oral Disorders and Cancer Transformation.

Cancer in the oral cavity is often preceded by precursor lesions. Nine oral mucosal disorders are known to have an increased risk of malignant transformation. The etiology varies from disorders caused by exogenous factors such as tobacco and autoimmune inflammation to idiopathic or inherited genetic aberrations. In this review, these potentially malignant disorders (PMDs) are described regarding clinical presentation and histopathological architecture. Special attention is paid to the underlying etiologies of PMDs and the potential pathways leading to cancer. The clinical perspective focuses on the importance of accurate and timely diagnosis.

Late Effects Screening Guidelines after Hematopoietic Cell Transplantation for Inherited Bone Marrow Failure Syndromes: Consensus Statement From the Second Pediatric Blood and Marrow Transplant Consortium International Conference on Late Effects After Pediatric HCT.

Patients with inherited bone marrow failure syndromes (IBMFS), such as Fanconi anemia (FA), dyskeratosis congenita (DC), or Diamond Blackfan anemia (DBA), can have hematologic manifestations cured through hematopoietic cell transplantation (HCT). Subsequent late effects seen in these patients arise from a combination of the underlying disease, the pre-HCT therapy, and the HCT process. During the international consensus conference sponsored by the Pediatric Blood and Marrow Transplant Consortium on late effects screening and recommendations following allogeneic hematopoietic cell transplantation for immune deficiency and nonmalignant hematologic diseases held in Minneapolis, Minnesota in May 2016, a half-day session was focused specifically on the unmet needs for these patients with IBMFS. This multidisciplinary group of experts in rare diseases and transplantation late effects has already published on the state of the science in this area, along with discussion of an agenda for future research. This companion article outlines consensus disease-specific long-term follow-up screening guidelines for patients with IMBFS.

Disceratose congênita - relato de caso e revisão de literatura / Dyskeratosis congenita - case report and literature review

A Disceratose Congênita (DC) é uma síndrome hereditária rara que exibe marcada heterogeneidade clínica e genética, constituindo-se em anormalidades cutaneomucosas, falência medular e predisposição ao câncer. Esta é caracterizada pela tríade de pigmentação reticulada da pele, distrofia ungueal e leucoplasia em mucosas. Alterações dentárias, gastrintestinais, geniturinárias, neurológicas, oftalmológicas, pulmonares e esqueléticas associadas têm sido relatadas. A falência medular é a principal causa de morte precoce e também é descrita predisposição para doenças malignas. Afeta principalmente homens e, reconhecem-se formas recessivas ligadas ao X, autossômicas dominantes e recessivas. Relata-se o caso de um paciente de 40 anos, sexo masculino, que há 7 evolui com quadro de anemia e necessidades transfusionais (sanguíneas). Investigadas causas hemofílica e carencial sem êxito. Mielograma com normocelularidade das linhagens; solicitada biópsia de medula óssea por suspeita de Disceratose Congênita, tendo em vista sintomatologia com presença da tríade da Disceratose Congênita: leucoplasia mucosa, distrofia ungueal, e áreas de hiperpigmentação reticular. Paciente progride sob acompanhamento no serviço hematológico do Hemocentro do Pará. Em função da raridade da doença, pouco mais de 500 casos relatados no mundo, da dificuldade de se chegar ao seu diagnóstico, e de sua gravidade, é de fundamental importância a difusão do conhecimento e ratifica-se a necessidade do acompanhamento médico multidisciplinar, de modo a permitir diagnóstico e tratamento precoce das possíveis complicações.

Dyskeratosis Congenita (DC) is a rare hereditary syndrome that shows marked clinical and genetic heterogeneity, like mucocutaneous abnormalities, bone marrow failure and predisposition to cancer. Dyskeratosis congenita triad is: abnormal skin pigmentation, nail dystrophy and mucosal leukoplakia. Dental, gastrointestinal, genitourinary, neurological, ophthalmic, pulmonary and skeletal disorders have been reported. The leading cause of early death and an additional predisposition to malignancy is bone marrow failure. Dyskeratosis congenita mainly affects men and recessive X-linked, autosomal dominant and recessive forms are recognized. We report the case of a 40-year-old male, 7 years evolving symptoms of anemia and transfusion requirements. Unsuccessfully research by deficiency causes and hemophilia were done. Normal cellular lineages myelogram. Patient progresses under supervision of Hemocenter of Pará (HEMOPA). Depending on the rarity of the disease, little more than 500 cases reported worldwide, the difficulty of arriving at a diagnosis, and its severity, is crucial to spreading knowledge and it confirms the need for a multidisciplinary approach, the to enable early diagnosis and treatment of possible complications.

Immune status of patients with inherited bone marrow failure syndromes.

Immune function abnormalities have been reported in patients with Fanconi anemia (FA), dyskeratosis congenita (DC) and, rarely, in Shwachman-Diamond syndrome (SDS), and Diamond-Blackfan anemia (DBA), but large systematic studies are lacking. We assessed immunological parameters in 118 patients with these syndromes and 202 unaffected relatives. We compared the results in patients with reference values, and with values in relatives after adjusting for age, sex, corticosteroid treatment, and severe bone marrow failure (BMF). Adult patients (≥18 years) with FA had significantly lower immunoglobulins (IgG, IgA and IgM), total lymphocytes, and CD4 T cells than reference values or adult relatives (P < 0.001); children with FA had normal values. Both children and adults with FA had lower B- and NK cells (P < 0.01) than relatives or reference values. Patients with DC had essentially normal immunoglobulins but lower total lymphocytes than reference values or relatives, and lower T-, B-, and NK-cells; these changes were more marked in children than adults (P < 0.01). Most patients with DBA and SDS had normal immunoglobulins and lymphocytes. Lymphoproliferative responses, serum cytokine levels, including tumor necrosis factor-α and interferon-γ, and cytokine levels in supernatants from phytohemagglutinin-stimulated cultures were similar across patient groups and relatives. Only patients with severe BMF, particularly those with FA and DC, had higher serum G-CSF and Flt3-ligand and lower RANTES levels compared with all other groups or relatives (P < 0.05). Overall, immune function abnormalities were seen mainly in adult patients with FA, which likely reflects their disease-related progression, and in children with DC, which may be a feature of early-onset severe disease phenotype.

Pneumococcal vaccine failure: can it be a primary immunodeficiency?

Vaccine failure is a rare condition and the need to investigate a primary immunodeficiency is controversial. We present the case of a 4-year-old boy, with complete antipneumococcal vaccination, who had necrotising pneumonia with pleural effusion and severe pancytopaenia with need for transfusion. A vaccine-serotype Streptococcus pneumoniae was isolated in the blood culture. On follow-up, detailed medical history, laboratory and genetic investigation led to the diagnosis of X linked dyskeratosis congenita. Dyskeratosis congenita is an inherited disorder that causes shortening or dysfunction of telomeres, affecting mainly rapidly dividing cells (particularly in the skin and haematopoietic system). It leads to bone marrow failure, combined immunodeficiency and predisposition to cancer. The confirmation of this diagnosis allows genetic counselling and medical monitoring of these patients, in order to detect early complications such as bone marrow aplasia or malignancies.

Neutrophil functions in patients with inherited bone marrow failure syndromes.

BACKGROUND: The inherited bone marrow failure syndromes (IBMFS) include Fanconi anemia, dyskeratosis congenita, Diamond-Blackfan anemia, and Shwachman-Diamond syndrome (SDS). Previous studies reported decreased neutrophil chemotaxis in patients with SDS; there are no reports of neutrophil function in other IBMFS. In this study we examined neutrophil respiratory burst function in IBMFS patients. PROCEDURE: Samples from 43 IBMFS patients and 61 healthy family members were collected, shipped, and analyzed within 24 hr. We also studied samples from 12 healthy control persons immediately after collection. Neutrophils were stimulated with phorbol 12-myristate acetate (PMA) and N-formyl-methyonyl-leucyl-phenylalanine (fMLP), and respiratory burst analyzed by reduction of dihydro-rhodamine and cytochrome c. RESULTS: There was no significant difference in the degree of fMLP or PMA-driven respiratory burst activity between each of the IBMFS subgroups and their respective family members. There was also no difference in respiratory burst activity between any IBMFS, pooled group of all healthy family members and healthy controls. CONCLUSIONS: Neutrophil respiratory burst activity from IBMFS patients does not differ from that of healthy family members and controls.

Dyskeratosis congenita and the DNA damage response.

Dyskeratosis congenita (DC) is a heterogeneous bone marrow failure disorder with known mutations in components of telomerase and telomere shelterin. Recent work in a mouse model with a dyskerin mutation has implicated an increased DNA damage response as part of the cellular pathology, while mouse models with Terc and Tert mutations displayed a normal response. To clarify how these contradictory results might apply to DC pathology in humans, we studied the cellular phenotype in primary cells from DC patients of several genetic subtypes, focussing on T lymphocytes to remain close to the haematopoietic system. We observed novel cell cycle abnormalities in conjunction with impaired growth and an increase in apoptosis. Using flow cytometry and confocal microscopy we examined induction of the DNA damage proteins γ-H2AX and 53BP1 and the cell cycle protein TP53 (p53). We found an increase in damage foci at telomeres in lymphocytes and an increase in the basal level of DNA damage in fibroblasts, but crucially no increased response to DNA damaging agents in either cell type. As the response to induced DNA damage was normal and levels of global DNA damage were inconsistent between cell types, DNA damage may contribute differently to the pathology in different tissues.

Dyskeratosis congenita: a combined immunodeficiency with broad clinical spectrum--a single-center pediatric experience.

BACKGROUND: Dyskeratosis Congenita (DKC) is a syndrome characterized by immunodeficiency, bone marrow failure, somatic abnormalities, and cancer predisposition resulting from defective telomere maintenance. The immunologic features of DKC remain under diagnosed and under treated despite the fact that immunodeficiency is a major cause of premature mortality in DKC. METHODS: This study undertook a retrospective review of 7 DKC patients diagnosed at the Children's Hospital of Philadelphia. In parallel, we reviewed previously reported immunologic findings in DKC patients. RESULTS: Immunologic abnormalities (lymphopenia, low B-cell numbers, hypogammaglobulinemia, and decreased T-cell function) were the most frequent laboratory findings at initial presentation, preceding the development of significant anemia or thrombocytopenia. Recurrent sinopulmonary or opportunistic infections were present in 6/7 patients. Infant-onset patients had more severe immunologic and somatic features (particularly severe enteropathy). CONCLUSION: In DKC, development of immunologic abnormalities can precede bone marrow failure, highlighting the importance of proper immunodeficiency management to minimize morbidity and premature mortality in this disease.

Dyskeratosis congenita.

Dyskeratosis congenita (DC) is an inheritable bone marrow failure syndrome characterized by reticulated hyperpigmentation, dystrophic nails and oral leukoplakia. Another name for the condition is Zinsser-Cole-Engman syndrome. Hematologic manifestations usually do not appear in childhood but later in early adulthood. Patients are also prone to carcinomas, particularly of the head and neck. The disease has X-linked or autosomal dominant/recessive inheritance. Early childhood variants (Hoyeraal-Hreidarsson syndrome) are associated with immunological abnormalities in the form of low T- and B-cell numbers. Four genes, namely DKC1 (codes for dyskerin), TERC and TERT (code for telomerase) and NOP10, have been implicated in the pathogenesis; the short telomeres provide a marker for genetic linkage studies. Androgens, with or without granulocyte colony stimulating factor, have been tried in the treatment of the conditions with variable results. Stem cell transplantation from matched sibling donor is currently the treatment of choice. It requires modified nonmyeloablative conditioning protocols, since the patients with DC are prone to pulmonary and hepatic complications.

Exogenous TERC alone can enhance proliferative potential, telomerase activity and telomere length in lymphocytes from dyskeratosis congenita patients.

Dyskeratosis congenita (DC) is an inherited multi-system disorder characterised by muco-cutaneous abnormalities, bone marrow failure and a predisposition to malignancy. Bone marrow failure is the principal cause of mortality and is thought to be the result of premature cell death in the haematopoietic compartment because DC cells age prematurely and tend to have short telomeres. DC is genetically heterogeneous and patients have mutations in genes that encode components of the telomerase complex (DKC1, TERC, TERT, NOP10 and NHP2), and telomere shelterin complex (TINF2), both important in telomere maintenance. Here, we transduced primary T lymphocytes and B lymphocyte lines established from patients with TERC and DKC1 mutations with wild type TERC-bearing lentiviral vectors. We found that transduction with exogenous TERC alone was capable of increasing telomerase activity in mutant T lymphocytes and B lymphocyte lines and improved the survival and thus overall growth of B-lymphocyte lines over a prolonged period, regardless of their disease mutation. Telomeres in TERC-treated lines were longer than in the untreated cultures. This is the first study of its kind in DC lymphocytes and the first to demonstrate that transduction with TERC alone can improve cell survival and telomere length without the need for exogenous TERT.

Intensive immunosuppression therapy for aplastic anemia associated with dyskeratosis congenita: report of a case.

Dyskeratosis congenita (DC) is a very rare inherited disorder characterized by skin pigmentation, nail dystrophy, and mucosal leukoplakia. It is also associated with a variety of noncutaneous abnormalities, such as fatal pulmonary complications, malignancy, and bone marrow failure. We report the case of a 32-year-old man with DC associated with severe aplastic anemia (SAA). The traditional treatment of DC-associated SAA is allogeneic hematopoietic stem cell transplantation (HSCT). However, in this case, an HLA-matched donor was not available. Therefore our patient was given intensive immunosuppressive therapy with antilymphocyte globulin (ALG) and cyclosporine A (CsA). The hemogram findings improved after the treatment, but the patient died of pulmonary complications after being in stable condition for 6 months. The results support the possible use of intensive immunosuppression with ALG and CsA for DC-associated SAA as an alternative treatment for patients who are not eligible for HSCT.

Association of immune abnormalities with telomere shortening in autosomal-dominant dyskeratosis congenita.

Dyskeratosis congenita (DC) is an inherited bone marrow failure disorder characterized by abnormal skin pigmentation and nail dystrophy. We have recently described, in 10 members of a large 3-generation family, an autosomal-dominant form of DC (AD DC) that is due to a mutation in the gene-encoding human telomerase RNA (TERC), resulting in telomere shortening. In studying the immunologic consequences of TERC mutations, severe B lymphopenia and decreased immunoglobulin M (IgM) levels were noted. T cells were found to overexpress senescent markers, including CD57 and Fas receptor, and were moderately reduced in cell number. To determine whether these in vivo findings were related to cellular replicative defects, short-term cultures of AD DC lymphocytes were established to measure proliferation, mitoses, and apoptosis. AD DC lymphocytes displayed a markedly reduced proliferative capacity and increased basal apoptotic rate. Finally, telomere shortening was most prominent in third-generation subjects, and there appeared to be a correlation between telomere length and in vivo and in vitro immune findings. In summary, the observed lymphopenia and hypogammaglobulinemia in AD DC is likely a consequence of replicative failure and premature senescence of lymphocytes, supporting a role of telomerase activity in immune homeostasis.

Enhanced telomere shortening in transformed lymphoblasts from patients with X linked dyskeratosis.

AIM: Dyskeratosis congenita (DC) is characterised by the failure of those tissues that are rapidly dividing in the adult, particularly the skin, mucosae, and haemopoietic system. The X linked form of the disease is caused by mutations of the DKC1 gene, which encodes dyskerin, a protein that is necessary for the function of telomerase. Cultured DC lymphoblastoid cells are characterised by a reduced expansion of the cell population because of the progressive increase in apoptosis compared with the number of cell divisions. This report aimed to verify whether this is caused by a defect in telomerase function. METHODS: Variations in telomere length over time were evaluated in two cultured lymphoblastoid cell lines derived from patients with X linked DC and control cells derived from a non-affected individual. In addition, the effect of inhibiting poly (ADP-ribose) polymerase (PARP), which is involved in the cellular response to excessive telomere shortening, was assessed. One DC cell line and the control cells were treated with the specific PARP inhibitor 1,5-dihydroxyquinoline (IQ). RESULTS: In DC cells the increase in cell death was associated with progressive telomere shortening, and this was not seen in the control cells. Treatment with IQ delayed the increase of apoptosis in DC cells. CONCLUSIONS: These observations indicate that the reduced expansion that characterises cultured cells obtained from patients with X linked DC is caused by premature telomere shortening.

[Zinsser-Engman-Cole syndrome (dyskeratosis congenita) with severe sicca syndrome, panuveitis and corneal perforation--a case report]. / Zinsser-Engman-Cole-Syndrom (Dyskeratosis congenita) mit schwerem Sicca-Syndrom, Panuveitis und Hornhautperforation--eine Kasuistik.

BACKGROUND: Zinsser-Engman-Cole syndrome (Z.E.C.) is a very rare type of ectodermal dysplasia, inherited in X-linked recessive manner and characterised by poikiloderma, nail dystrophy, lingual leucoplakia, bone marrow hypoplasia, hyperkeratosis and hyperhidrosis of planta and palms, dental anomalies and caries, premature grey hair. PATIENT AND METHODS: We report on a 46-year-old man who presented with occlusion of lacrimal puncta, trichiasis, severe dry eye, recurrent corneal ulceration and perforation, uveitis. HLA typing, flow cytometry of peripheral lymphocytes, bone marrow biopsy, conjunctival biopsy and extensive laboratory evaluation towards autoimmune and infectious diseases were performed. RESULTS: CD4+ T cells fraction was decreased, CD8+ and CD3+ HLA DR+ elevated. The patient was HLA-B27 positive. Laboratory studies revealed increased erythrocyte sedimentation rate and C-reactive protein level, hypochromic and hypoplastic anaemia, negative serum titers of antibodies to Epstein-Barr virus, HIV, HTLV-I, toxoplasma gondii and treponema pallidum, repeated titers to cytomegalovirus, herpes simplex and herpes zoster viruses--IgM negative, IgG positive. Corneal perforation was treated with amniotic membrane transplantation and corneal transplantation. CONCLUSION: The defect in cell-mediated immune mechanisms in Z.E.C. syndrome explains the corneal perforation, sicca syndrome and uveitis, first reported in this syndrome.

Analysis of epitope-tagged forms of the dyskeratosis congenital protein (dyskerin): identification of a nuclear localization signal.

The X-linked form of the bone marrow failure syndrome Dyskeratosis congenital is caused by mutations in dyskerin, a 514 amino acid protein that is presumed to play a role in ribosome biogenesis. Here we report that dyskerin tagged with the human immunoglobulin epitope localizes to nuclei of transfected HeLa and COS-1 cells. A carboxyl-terminal domain consisting of amino acids 467-475 and encoding KKEKKKSKK is both necessary and sufficient to mediate nuclear entry. Immunoglobulin-tagged dyskerin did not interact with the Fanconi anemia group A protein, FANCA. These results suggest a nuclear role for dyskerin. Moreover, hematopoietic failure observed in both Dyskeratosis congenital and the most common type of Fanconi anemia is unlikely to have a common mechanism resulting from abnormal physical interactions between the respective gene products of these disorders.

Dyskeratosis congenita: multisystemic disorder with special consideration of immunologic aspects. A review of the literature.

Dyskeratosis congenita (DC) is a rare, predominantly X-linked multisystemic disorder. It demonstrates a wide spectrum of clinical manifestations and typically presents with dermatologic symptoms during the first decade of life. This review of the literature points out the importance of hematologic and immunologic alterations in defining the course and prognosis of the disease process. Pancytopenia as well as the humoral and cellular disturbances in immunologic functions associated with this disease complex may lead to severe infections that represent the main cause of death. The pathogenesis of DC is still unclear and a curative therapy is presently lacking. Recent reports suggest that a beneficial effect may be observed in the administration of hematopoietic growth factors (G-CSF, GM-CSF) for patients with DC and neutropenia.