A rare CTSC mutation in Papillon-Lefèvre Syndrome results in abolished serine protease activity and reduced NET formation but otherwise normal neutrophil function.

Papillon-Lefèvre Syndrome (PLS) is an autosomal recessive monogenic disease caused by loss-of-function mutations in the CTSC gene, thus preventing the synthesis of the protease Cathepsin C (CTSC) in a proteolytically active form. CTSC is responsible for the activation of the pro-forms of the neutrophil serine proteases (NSPs; Elastase, Proteinase 3 and Cathepsin G), suggesting its involvement in a variety of neutrophil functions. In PLS neutrophils, the lack of CTSC protease activity leads to inactivity of the NSPs. Clinically, PLS is characterized by an early, typically pre-pubertal, onset of severe periodontal pathology and palmoplantar hyperkeratosis. However, PLS is not considered an immune deficiency as patients do not typically suffer from recurrent and severe (bacterial and fungal) infections. In this study we investigated an unusual CTSC mutation in two siblings with PLS, a 503A>G substitution in exon 4 of the CTSC gene, expected to result in an amino acid replacement from tyrosine to cysteine at position 168 of the CTSC protein. Both patients bearing this mutation presented with pronounced periodontal pathology. The characteristics and functions of neutrophils from patients homozygous for the 503A>G CTSC mutation were compared to another previously described PLS mutation (755A>T), and a small cohort of healthy volunteers. Neutrophil lysates from patients with the 503A>G substitution lacked CTSC protein and did not display any CTSC or NSP activity, yet neutrophil counts, morphology, priming, chemotaxis, radical production, and regulation of apoptosis were without any overt signs of alteration. However, NET formation upon PMA-stimulation was found to be severely depressed, but not abolished, in PLS neutrophils.

Cathepsin C inhibitors as anti-inflammatory drug discovery: Challenges and opportunities.

Cathepsin C, an important lysosomal cysteine protease, mediates the maturation process of neutrophil serine proteases, and participates in the inflammation and immune regulation process associated with polymorphonuclear neutrophils. Therefore, cathepsin C is considered to be an attractive target for treating inflammatory diseases. With INS1007 (trade name: brensocatib) being granted a breakthrough drug designation by FDA for the treatment of Adult Non-cystic Fibrosis Bronchiectasis and Coronavirus Disease 2019, the development of cathepsin C inhibitor will attract attentions from medicinal chemists in the future soon. Here, we summarized the research results of cathepsin C as a therapeutic target, focusing on the development of cathepsin C inhibitor, and provided guidance and reference opinions for the upcoming development boom of cathepsin C inhibitor.

Clinical and molecular analysis in Papillon-Lefèvre syndrome.

Papillon-Lefèvre syndrome (PLS; MIM#245000) is a rare recessive autosomal disorder characterized by palmar and plantar hyperkeratosis, and aggressively progressing periodontitis leading to premature loss of deciduous and permanent teeth. PLS is caused by loss-of-function mutations in the CTSC gene, which encodes cathepsin C. PLS clinical expressivity is highly variable and no consistent genotype-phenotype correlation has been demonstrated yet. Here we report the clinical and genetic features of five PLS patients presenting a severe periodontal breakdown in primary and permanent dentition, hyperkeratosis over palms and soles, and recurrent sinusitis and/or tonsillitis. Mutation analysis revealed two novel homozygous recessive mutations (c.947T>C and c.1010G>C) and one previous described homozygous recessive mutation (c.901G>A), with parents carrying them in heterozygous, in three families (four patients). The fourth family presented with the CTSC c.628C>T mutation in heterozygous, which was inherited maternally. Patient carrying the CTSC c.628C>T mutation featured classical PLS phenotype, but no PLS clinical characteristics were found in his carrier mother. All mutations were found to affect directly (c.901G>A, c.947T>C, and c.1010G>C) or indirectly (c.628C>T, which induces a premature termination) the heavy chain of the cathepsin C, the region responsible for activation of the lysosomal protease. Together, these findings indicate that both homozygous and heterozygous mutations in the cathepsin C heavy chain domain may lead to classical PLS phenotype, suggesting roles for epistasis or gene-environment interactions on determination of PLS phenotypes.

Characterization of neutrophil function in Papillon-Lefèvre syndrome.

Papillon-Lefévre syndrome is a rare, inherited, autosomal-recessive disease, characterized by palmoplantar keratosis and severe prepubertal periodontitis, leading to premature loss of all teeth. Papillon-Lefévre syndrome is caused by a mutation in the cathepsin C gene, resulting in complete loss of activity and subsequent failure to activate immune response proteins. Periodontitis in Papillon-Lefévre syndrome is thought to arise from failure to eliminate periodontal pathogens as a result of cathepsin C deficiency, although mechanistic pathways remain to be elucidated. The aim of this study was to characterize comprehensively neutrophil function in Papillon-Lefévre syndrome. Peripheral blood neutrophils were isolated from 5 patients with Papillon-Lefévre syndrome, alongside matched healthy control subjects. For directional chemotactic accuracy, neutrophils were exposed to the chemoattractants MIP-1α and fMLP and tracked by real-time videomicroscopy. Reactive oxygen species generation was measured by chemiluminescence. Neutrophil extracellular trap formation was assayed fluorometrically, and proinflammatory cytokine release was measured following overnight culture of neutrophils with relevant stimuli. Neutrophil serine protease deficiencies resulted in a reduced ability of neutrophils to chemotax efficiently and an inability to generate neutrophil extracellular traps. Neutrophil extracellular trap-bound proteins were also absent in Papillon-Lefévre syndrome, and Papillon-Lefévre syndrome neutrophils released higher levels of proinflammatory cytokines in unstimulated and stimulated conditions, and plasma cytokines were elevated. Notably, neutrophil chemoattractants MIP-1α and CXCL8 were elevated in Papillon-Lefévre syndrome neutrophils, as was reactive oxygen species formation. We propose that relentless recruitment and accumulation of hyperactive/reactive neutrophils (cytokines, reactive oxygen species) with increased tissue transit times into periodontal tissues, alongside a reduced antimicrobial capacity, create a locally destructive chronic inflammatory cycle in Papillon-Lefévre syndrome.

Papillon-Lèfevre syndrome with palmoplantar keratoderma and periodontitis, a rare cause of pyrexia of unknown origin: a case report.

INTRODUCTION: Papillon-Lefèvre Syndrome is a rare autosomal recessive disorder characterized by diffuse, transgradient palmoplantar keratoderma, destructive periodontitis beginning in childhood, premature loss of primary teeth, and frequent cutaneous and systemic pyogenic infections. Pyogenic liver abscess is an uncommon presentation of the disease present in this case. CASE PRESENTATION: A 16-year-old Punjabi, Pakistani boy presented to the outpatient department of a tertiary-care hospital of Lahore with high-grade fever of 2 months duration. He had been treated for a pyogenic liver abscess 2 years back with antibiotics followed by incision and drainage. He had poor orodental hygiene, palmoplantar keratoderma and periodontitis. His parents had history of consanguinity. His brother and two cousins had similar skin lesions and were edentulous. An orthopentogram showed atrophy of the alveolar bone. He was treated with broad-spectrum antibiotics, and antipyretics for systemic infection. Multivitamins, topical steroids, topical keratolytics and emollients were used for his dermatological issues. CONCLUSIONS: Our patient was successfully treated. His fever settled and his skin lesions improved with antibiotics, topical steroids and keratolytics. He was sent home and was asked to return for follow-up on a monthly basis.

Multiple cerebral abscesses in Papillon-Lefèvre syndrome.

Papillon-Lefèvre syndrome is characterised by palmoplantar keratoderma, periodontitis and pyogenic infections. We describe the first case of brain abscess in a child with this syndrome. We highlight the importance of recognising any associated diagnosis, however rare or apparently irrelevant, in an acutely and critically ill child.

Isolation and characterization of dental pulp stem cells from a patient with Papillon-Lefèvre syndrome.

INTRODUCTION: Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder characterized by immune dysregulation because of a mutation in cathepsin c gene, resulting in hyperkeratosis of the palms, soles, elbows, and knees combined with premature loss of the primary and permanent dentitions. Periodontal tissue abnormalities in PLS patients were reported previously. However, less is known about dental pulp tissue derived cells of PLS patients. This study aimed to show stem cell potential of PLS dental pulp stem cells (DPSCs) and provide new evidence regarding the pathophysiology of the disease. METHODS: DPSCs were characterized by using flow cytometry and immunocytochemistry. They were also induced to differentiate into adipogenic, osteogenic, chondrogenic, odontogenic, and myogenic cells. RESULTS: The results revealed that PLS DPSCs are stained positive for mesenchymal stem cells surface markers CD29, CD73, CD90, CD105, and CD166. PLS DPSCs were able to differentiate into adipogenic, osteogenic, chondrogenic, and odontogenic cell types properly. PLS DPSCs expressed embryonic stem cell markers Oct4, Sox2, cMYc, and Klf4 and showed similar proliferation rate compared with DPSCs isolated from healthy young controls. Interestingly, it was found that unlike the healthy DPSCs, PLS DPSCs are not able to form myotubes with correct morphology. CONCLUSIONS: These data are being reported for the first time; therefore, they might provide new insights to the pathology of the disease. Our results suggest that the PLS DPSCs might be an autologous stem cell source for PLS patients for cellular therapy of alveolar bone defects and other dental tissue abnormalities observed in PLS.

Neutral lipid storage disease with unusual presentation: report of three cases.

Neutral lipid storage disease is a nonlysosomal multisystemic triglyceride storage disease. It is characterized by leukocyte vacuolization (Jordans' anomaly), variable systemic involvement, and ichthyosis. Two of our patients presented with congenital ichthyosis. Lipid vacuoles were demonstrated in granulocytes and monocytes and in basal keratinocytes on skin biopsy. They were diagnosed as Chanarin Dorfman syndrome. In contrast to these cases, the third case presented with progressive symmetric erythrokeratoderma without ichthyosis. Lipid vacuoles were demonstrated in blood cells on peripheral smear and in basal keratinocytes. Only screening of peripheral smear led to the correct diagnosis.

Papillon-Lefevre syndrome.

Papillon-Lefevre syndrome is a very rare syndrome of autosomal recessive inheritance characterized by palmoplanter hyperkeratosis of the skin and severe periodontal disease extending to destruction of the alveolar bone surrounding deciduous and permanent teeth as they erupt leading to precocious loss of dentition. Although the exact pathogenesis of this syndrome is still unknown immunologic, microbiologic, and genetic bases have been proposed. Here we report a case of Papillon-Lefevre syndrome. The patient had generalized plaque accumulation along with halitosis, mobile teeth with periodontal pocket with pus exudation. Blood & biochemical report was within normal limit with a low CD3+ and CD4+.

Cutaneous paraneoplasia.

Paraneoplasias are frequently the first sign of a subjacent malignant tumor. Although relatively rare, they need to be recognized by dermatologists to make an early diagnosis and improve the prognosis related especially to the neoplasia. This contribution presents the morphologic aspects and the differential diagnosis of the main paraneoplasias, which include acanthosis nigricans, tripe palms, Leser-Trélat sign, acquired ichthyosis, acquired hypertrichosis lanuginosa, pityriasis rotunda, erythema gyratum repens, palmo-plantar keratoderma, Bazex syndrome, and dermatomyositis, hoping to contribute to the familiarity of dermatologists with the identification and early diagnosis of this group.

Haim Munk syndrome and Papillon Lefevre syndrome--allelic mutations in cathepsin C with variation in phenotype.

Papillon-Lefevre syndrome and Haim Munk syndrome are palmoplantar keratodermas associated with premature periodontal destruction. The additional findings of Haim Munk Syndrome include onychogryphosis, arachnodactyly, acral osteolysis and pes planus. Both are associated with mutations in the lysosomal protease cathepsin C. We describe a patient with phenotype for Haim Munk Syndrome and genetic analysis revealed a homozygous point mutation in exon 1 of the gene encoding cathepsin C.

Evidence for a founder mutation in the cathepsin C gene in three families with Papillon-Lefèvre syndrome.

BACKGROUND: Papillon-Lefèvre syndrome (PLS; OMIM 245000) is a rare autosomal recessive disorder. Clinically, PLS is characterized by hyperkeratosis involving the palms, soles, elbows and knees which is followed later on by periodontitis, destruction of alveolar bone and loss of primary and permanent teeth. The condition is caused by mutations in the cathepsin C (CTSC) gene. METHODS: We analyzed the DNA of members from 3 consanguineous families for mutations in the CTSC gene by direct sequencing analysis. We then performed haplotype analysis. RESULTS: We identified an identical recurrent missense mutation, R272P, in all 3 families. Microsatellite marker analysis around the CTSC gene revealed the same haplotype on the mutation-carrying allele in all 3 families. CONCLUSION: The presence of this common mutation in families from 2 different geographical areas provides evidence for a founder effect for CTSC mutations in PLS.