Homozygosity for a Rare Plec Variant Suggests a Contributory Role in Congenital Insensitivity to Pain.

Congenital insensitivity to pain is a rare human condition in which affected individuals do not experience pain throughout their lives. This study aimed to identify the molecular etiology of congenital insensitivity to pain in two Thai patients. Clinical, radiographic, histopathologic, immunohistochemical, and molecular studies were performed. Patients were found to have congenital insensitivity to pain, self-mutilation, acro-osteolysis, cornea scars, reduced temperature sensation, tooth agenesis, root maldevelopment, and underdeveloped maxilla and mandible. The skin biopsies revealed fewer axons, decreased vimentin expression, and absent neurofilament expression, indicating lack of dermal nerves. Whole exome and Sanger sequencing identified a rare homozygous variant c.4039C>T; p.Arg1347Cys in the plakin domain of Plec, a cytolinker protein. This p.Arg1347Cys variant is in the spectrin repeat 9 region of the plakin domain, a region not previously found to harbor pathogenic missense variants in other plectinopathies. The substitution with a cysteine is expected to decrease the stability of the spectrin repeat 9 unit of the plakin domain. Whole mount in situ hybridization and an immunohistochemical study suggested that Plec is important for the development of maxilla and mandible, cornea, and distal phalanges. Additionally, the presence of dental anomalies in these patients further supports the potential involvement of Plec in tooth development. This is the first report showing the association between the Plec variant and congenital insensitivity to pain in humans.

Rare Filaggrin Variants Are Associated with Pustular Skin Diseases in Asians.

Reactive pustular eruptions (RPEs) can manifest in a variety of conditions, including pustular psoriasis (PP) and adult-onset immunodeficiency syndrome due to anti-interferon-γ autoantibody (AOID). These RPEs can be attributed to different causes, one of which is genetic factors. However, the genetic basis for pustular skin diseases remains poorly understood. In our study, we conducted whole-exome sequencing on a cohort of 17 AOID patients with pustular reactions (AOID-PR) and 24 PP patients. We found that 76% and 58% of the AOID-PR and PP patients, respectively, carried rare genetic variations within the filaggrin (FLG) gene family. A total of 12 out of 21 SNPs on FLG had previously received clinical classifications, with only p.Ser2706Ter classified as pathogenic. In contrast, none of the FLG3 SNPs identified in this study had prior clinical classifications. Overall, these variations had not been previously documented in cases of pustular disorders, and two of them were entirely novel discoveries. Immunohistochemical analysis of skin biopsies revealed that FLG variants like p.Ser860Trp, p.Gly3903Ter, p.Gly2440Glu, and p.Glu2133Asp caused reductions in FLG levels similar to the pathogenic FLG p.Ser2706Ter. These results highlight rare FLG variants as potential novel genetic risk factors contributing to pustule formation in both AOID and PP.

Age-related EBV-associated B-cell lymphoproliferative disorders and other EBV + lymphoproliferative diseases: New insights into immune escape and immunodeficiency through staining with anti-PD-L1 antibody clone SP142.

Epstein-Barr virus (EBV) is prevalent among healthy individuals, and is implicated in numerous reactive and neoplastic processes in the immune system. The authors originally identified a series of senile or age-related EBV-associated B-cell lymphoproliferative disorders (LPD) bearing a resemblance to immunodeficiency-associated ones. These LPDs may be associated with immune senescence and are now incorporated into the revised 4th edition of 2017 WHO lymphoma classification as EBV-positive (EBV+) diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS). These EBV+ B-cells often have a Hodgkin/Reed-Sternberg (HRS)-like appearance and are shared beyond the diagnostic categories of mature B-cell neoplasms, mature T-cell neoplasms, classic Hodgkin lymphoma, and immunodeficiency-associated LPD. In addition, peculiar new diseases, such as EBV+ mucocutaneous ulcer and EBV+ DLBCL affecting the young, were recognized. On the other hand, lymphoma classification is now evolving in accord with deeper understanding of the biology of programmed death ligand 1 (PD-L1). Assessing PD-L1 positivity by staining with the anti-PD-L1 monoclonal antibody SP142 provides new insight by discriminating between immune evasion and senescence or immunodeficiency. The aim of the present review is to briefly summarize the diagnostic use of immunostaining with SP142 in malignant lymphomas and/or LPDs that feature tumor and nonmalignant large B-cells harboring EBV.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma arising in patient with a history of EBV-positive mucocutaneous ulcer and EBV-positive nodal polymorphous B-lymphoproliferative disorder.

Elderly patients with Epstein-Barr virus (EBV) infection are at increased risk for developing B-cell lymphoproliferative disorder (B-LPD) due to immunosenescence. Here, we describe a case of a 75-year-old man who developed an EBV-positive (EBV+) mucocutaneous ulcer (EBVMCU) in the gingiva with spontaneous regression. Eighteen months after regression, he had a cervical lymph node enlargement that was diagnosed as EBV+ nodal polymorphous B-LPD, Ann Arbor stage IA. Clinicians decided to observe his clinical course without any treatment. Fourteen months later, the patient developed EBV-positive diffuse large B-cell lymphoma (DLBCL), Ann Arbor stage IIA, and received six courses of age-adjusted dose chemotherapy and achieved a complete remission. No evidence of a clonal relationship was found among these three lesions by standard polymerase chain reaction (PCR) analysis for immunoglobulin heavy chain. However, they all had expression of PD-L1 in the EBV+ large B-cells and Hodgkin Reed-Sternberg-like cells. This is the first case report of a PD-L1-positive (PD-L1+) EBVMCU and the development of multiple EBV-driven B-LPDs in the setting of immunosenescence within a 32-month period.

Comparison of Epstein-Barr virus-positive mucocutaneous ulcer associated with treated lymphoma or methotrexate in Japan.

AIMS: The aim of the present study was to compare treated lymphoma-associated Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) and methotrexate (MTX)-associated EBVMCU. METHODS AND RESULTS: Of a series of 15 Japanese patients (11 women, four men; median age 74 years, range 35-84 years), seven received MTX for the treatment of autoimmune disease and eight developed EBVMCU after treatment of malignant lymphoma [diffuse large B-cell lymphoma (n = 4) without EBV association, adult T-cell leukaemia/lymphoma (n = 2), angioimmunoblastic T-cell lymphoma (n = 1), and follicular lymphoma (n = 1)]. Ulcers were observed in the oral cavity (n = 11), gastrointestinal tract (n = 2), and skin (n = 2). All were histologically characterised by a mixture of EBV-positive large B-cell proliferation and Hodgkin/Reed-Sternberg-like cells on a polymorphous background. A total of 46% (6/13) had monoclonal immunoglobulin heavy chain gene rearrangement, but none had clonal T-cell receptor gene rearrangement. Spontaneous regression occurred in 13 of 15 cases (87%); the other two cases (13%) achieved complete remission after treatment. Of two patients in the treated lymphoma-associated subgroup, one developed multiple new ulcerative lesions on previously unaffected skin, and the other had a relapse of EBVMCU in the oral cavity. No significant clinicopathological differences were found between the subgroups. Notably, none of the patients died from EBVMCU. However, the treated lymphoma-associated subgroup had lower overall survival (P = 0.004) and a shorter follow-up period (P = 0.003) than the MTX-associated subgroup, owing to death from non-associated causes. CONCLUSIONS: Treated lymphoma-associated EBVMCU, which is an indolent and self-limited condition, must be recognised to avoid misdiagnosing it as a relapse of malignant lymphoma during treatment.

Anaplastic variant of diffuse large B-cell lymphoma with hallmark cell appearance: Two cases highlighting a broad diversity in the diagnostics.

The anaplastic variant of diffuse large B-cell lymphoma (A-DLBCL) is morphologically defined but remains an enigmatic disease in its clinicopathologic distinctiveness. Here, we report two cases involving Japanese women aged 59 years, both with A-DLBCL with the hallmark cell appearance and both indistinguishable from common and giant cell-rich patterns, respectively, of anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma. Case 1 was immunohistochemically positive for CD20, CD79a and OCT-2 but not for the other pan-B-cell markers, CD30 and ALK. Case 2 showed CD20 and CD30 positivity for 50% and 20% of tumor cells in addition to strong expression of p53 and MYC. Both were positive for fascin without Epstein-Barr virus association. Our cases provide additional support for the earlier reports that A-DLBCL exhibits clinicopathologic features distinct from ordinal diffuse large B-cell lymphoma (DLBCL), and documented its broader morphologic diversity than previously recognized. They also shed light on the unique feature of absent expression of pan-B-cell markers except for CD20 and CD79a, suggesting that A-DLBCL may biologically mimic a gray zone or intermediate lymphoma between DLBCL and classic Hodgkin lymphoma.

Immunohistochemistry-based investigation of MYC, BCL2, and Ki-67 protein expression and their clinical impact in diffuse large B-cell lymphoma in upper Northern Thailand.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive type of non-Hodgkin lymphoma (NHL) that accounts for approximately 25-40% of all NHL cases. The objective of this study was to investigate the protein expression, clinical impact, and prognostic role of MYC, BCL2, and Ki-67 in Thai DLBCL patients. A retrospective analysis was conducted on 100 DLBCL patients diagnosed between January 2018 and December 2019. Immunohistochemistry was used to assess the expression of MYC, BCL2, and Ki-67. The study revealed a significant association between extranodal involvement and positive cases of MYC and BCL2. MYC expressions were associated with Ki-67 expression, while BCL2 positivity was associated with the non-germinal center B-cell (non-GCB) subtype. However, there were no significant differences in the three-year overall survival (OS) and three-year progression-free survival (PFS) rates when using cut-off points of ≥ 40% for MYC, ≥ 50% for BCL2, and ≥ 70% for Ki-67. Notably, DLBCL cases with co-expression of MYC and BCL2 exhibited significantly inferior three-year OS compared to other cases (0% vs. 53%; p = 0.020). Multivariate analysis identified age ≥ 60 years and Eastern Cooperative Oncology Group (ECOG) performance status as independent prognostic factors. In conclusion, MYC, BCL2, and Ki-67 expression can serve as prognostic biomarkers; however, their prognostic value may vary based on the specific cut-off values used. Therefore, determining the appropriate threshold for each biomarker based on individual laboratory analyses and clinical outcomes is crucial.

Comparative immunohistochemical analysis of inflammatory cytokines in distinct subtypes of Sweet syndrome.

Background: A dysregulated immune response has been implicated in Sweet syndrome (SS) pathogenesis; however, cytokine profiles across different conditions associated with SS - including adult-onset immunodeficiency (AOID) due to anti-interferon (IFN)-γ autoantibodies - remain unknown. Objective: To investigate alterations in inflammatory cytokines in skin lesions of distinct subtypes of SS. Methods: Skin biopsies were collected from 42 AOID- and 52 non-AOID-associated SS patients and 18 healthy controls. The comparative immunohistochemical study was conducted using monoclonal antibodies against interleukin (IL)-1ß, IL-6, IL-17, IFN-γ, and tumor necrosis factor-α on paraffin-embedded sections. The quantitative percentage positivity and intensity were calculated using computer-based image analysis. Results: The results showed stronger and more diffuse dermal immunoreactivity for IFN-γ and IL-17 in the AOID-associated (p < 0.001 and p < 0.001, respectively) and non-AOID-associated SS (p < 0.001 and p < 0.001, respectively) groups. However, no significant differences in the levels of these two cytokines were observed between the AOID- and non-AOID-associated SS groups. Increased expression of IFN-γ together with IL-17 was also noted in almost all subtypes among non-AOID-associated SS. Conclusions: These results demonstrate that IFN-γ and IL-17 are implicated in immunopathology of all SS subtypes, including AOID-associated SS, despite the presence of anti-IFN-γ autoantibodies.

SERPINB3, Adult-Onset Immunodeficiency, and Generalized Pustular Psoriasis.

BACKGROUND: Generalized pustular psoriasis (GPP; MIM 614204) is a rare and severe pustular autoinflammatory skin disease in which acute generalized erythema and scaling develop with numerous sterile pustules. GPP shares skin manifestations, especially pustular skin reaction, with adult-onset immunodeficiency (AOID) with anti-interferon-γ autoantibodies, an autoimmune disease. METHODS: Clinical examinations and whole-exome sequencing (WES) were performed on 32 patients with pustular psoriasis phenotypes and 21 patients with AOID with pustular skin reaction. Immunohistochemical and histopathological studies were performed. RESULTS: WES identified three Thai patients presenting with similar pustular phenotypes-two with a diagnosis of AOID and the other with GPP. A heterozygous missense variant chr18:g.61325778C>A NM_006919.2: c.438G>T; NP_008850.1: p.Lys146Asn; rs193238900 in SERPINB3 was identified in two patients: one with GPP and the other with AOID. The other patient who had AOID carried a heterozygous missense variant chr18:g.61323147T>C NM_006919.2: c.917A>G; NP_008850.1: p.Asp306Gly in SERPINB3. Immunohistochemical studies showed overexpression of SERPINA1 and SERPINB3, a hallmark of psoriatic skin lesions. CONCLUSIONS: Genetic variants in SERPINB3 are associated with GPP and AOID with pustular skin reaction. The skin of patients with GPP and AOID carrying SERPINB3 mutations showed overexpression of SERPINB3 and SERPINA1. Clinically and genetically, GPP and AOID appear to share pathogenetic mechanisms.

Loss of Function TGFBR2 Variant as a Contributing Factor in Generalized Pustular Psoriasis and Adult-Onset Immunodeficiency.

BACKGROUND: Generalized pustular psoriasis (GPP; MIM 614204) is a rare multisystemic autoinflammatory disease, characterized by episodes of acute generalized erythema and scaling developed with the spread of numerous sterile pustules. Adult-onset immunodeficiency syndrome (AOID) with anti-interferon-γ autoantibodies is an immunodeficiency disorder associated with disruptive IFN-γ signaling. METHODS: Clinical examination and whole exome sequencing (WES) were performed on 32 patients with pustular psoriasis phenotypes and 21 patients with AOID with pustular skin reaction. Histopathological and immunohistochemical studies were performed. RESULTS: WES identified four Thai patients presenting with similar pustular phenotypes-two with a diagnosis of GPP and the other two with AOID-who were found to carry the same rare TGFBR2 frameshift mutation c.458del; p.Lys153SerfsTer35, which is predicted to result in a marked loss of functional TGFBR2 protein. The immunohistochemical studied showed overexpression of IL1B, IL6, IL17, IL23, IFNG, and KRT17, a hallmark of psoriatic skin lesions. Abnormal TGFB1 expression was observed in the pustular skin lesion of an AOID patient, suggesting disruption to TGFß signaling is associated with the hyperproliferation of the psoriatic epidermis. CONCLUSIONS: This study implicates disruptive TGFBR2-mediated signaling, via a shared truncating variant, c.458del; p.Lys153SerfsTer35, as a "predisposing risk factor" for GPP and AOID.

Localised nasopharyngeal amyloidosis: the importance of postoperative follow-up.

Localised nasopharyngeal amyloidosis is rare. Findings on physical examination and invasive pattern on CT scan can be misleading as it can resemble nasopharyngeal carcinoma. A 64-year-old man presented with left aural fullness for 6 months. The physical examination showed straw-coloured fluid in the left middle ear and irregular reddish mass at the left side of the nasopharynx. The CT scan showed a lobulated heterogeneous mass at the left side of the nasopharynx involving the left Eustachian tube opening. Pathology report was amyloidosis, thus, surgery was done. After a year, there were new foci of amyloidosis at the right side of the nasopharynx, and a repeat surgery was performed. Two years later, the systemic amyloidosis with underlying IgG4-related disease was suspected due to multiple organ involvement. Surgery is the treatment for localised amyloidosis with compressive symptoms. Close follow-up is important after surgical excision due to its recurrence and progression to systemic amyloidosis.

Leishmania (Mundinia) orientalis n. sp. (Trypanosomatidae), a parasite from Thailand responsible for localised cutaneous leishmaniasis.

BACKGROUND: Leishmaniasis is an emerging disease in Thailand with an unknown incidence or prevalence. Although the number of properly characterized and clinically confirmed cases is about 20, it is suspected that this low number masks a potentially high prevalence, with clinical disease typically manifesting itself against an immunocompromised background, but with a substantial number of subclinical or cured cases of infection. To date leishmaniasis in Thailand has been mainly ascribed to two taxa within the recently erected subgenus Mundinia Shaw, Camargo & Teixeira, 2016, Leishmania (Mundinia) martiniquensis Desbois, Pratlong & Dedet, 2014 and a species that has not been formally described prior to this study. RESULTS: A case of simple cutaneous leishmaniasis was diagnosed in a patient from Nan Province, Thailand. Molecular analysis of parasites derived from a biopsy sample revealed this to be a new species of Leishmania Ross, 1908, which has been named as Leishmania (Mundinia) orientalis Bates & Jariyapan n. sp. A formal description is provided, and this new taxon supercedes some isolates from the invalid taxon "Leishmania siamensis". A summary of all known cases of leishmaniasis with a corrected species identification is provided. CONCLUSIONS: Three species of parasites are now known to cause leishmaniasis is Thailand, L. martiniquensis and L. orientalis n. sp. in the subgenus Mundinia, which contains the type-species Leishmania enriettii Muniz & Medina, 1948, and a single case of Leishmania infantum Nicolle, 1908. This study now enables epidemiological and other investigations into the biology of these unusual parasites to be conducted. It is recommended that the use of the taxonomically invalid name "L. siamensis" should be discontinued.