Loss-of-function mutations in filaggrin gene and malignant melanoma: a case-control study.

BACKGROUND: Loss-of-function mutations in filaggrin gene (FLG) have been suggested to increase the susceptibility of skin malignancies due to reduced levels of epidermal filaggrin and its degradation products, urocanic acid, which may be protective against ultraviolet irradiation. OBJECTIVE: We aimed to investigate the association between FLG mutation status and the occurrence of malignant melanoma (MM) in Danish adults. METHODS: The prevalence of FLG mutations in a sample of MM biopsies was compared with a FLG-genotyped cohort from two general population studies. Pearson's chi-squared and Fisher's exact tests were used to compare the two groups. RESULTS: A total of 867 MM biopsies and 9965 general population controls were genotyped, respectively. In the MM sample, two (0.23%) individuals were homozygous and 80 (9.4%) were heterozygous mutation carriers. In the general population controls, the prevalence of FLG mutations was 18 (0.18%) and 835 (8.4%) for homozygous and heterozygous mutations, respectively. Fisher's exact test and Pearson's chi-squared test yielded non-significant P-values when the groups were compared. CONCLUSION: FLG mutation was not associated with MM in the studied populations. This finding indicates that epidermal deficiency of filaggrin and its degradation products does not influence the risk of MM significantly.

Factor V Leiden is associated with increased sperm count.

STUDY QUESTION: Is the thrombophilia mutation factor V Leiden (FVL) associated with an increased total sperm count? SUMMARY ANSWER: Carriers of FVL have a higher total sperm count than non-FVL-carriers, which could not be explained by genetic linkage or by observations in a FVL-mouse model. WHAT IS KNOWN ALREADY: FVL has a high prevalence in Caucasians despite detrimental health effects. Carriers have been shown to have higher fecundity, which might partly explain this evolutionary paradox. STUDY DESIGN, SIZE, DURATION: We determined FVL status in two cohorts (Dutch, n = 627; Danish, n = 854) of consecutively included men without known causes for spermatogenic failure, and performed an individual patient data meta-analysis of these two cohorts together with one previously published (Dutch, n = 908) cohort. We explored possible biological underpinnings for the relation between sperm count and FVL, by use of a FVL-mouse model and investigations of genetic linkage. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were male partners of subfertile couples (two Dutch cohorts) and young men from the general population (Danish cohort): FVL carrier rate was 4.0%, 4.6% and 7.3%, respectively. There were differences in smoking, abstinence time and age between the cohorts. We corrected for these in the primary analysis, which consisted of a mixed linear effects model, also incorporating unobjectified population differences. In public haplotype data from subjects of European descent, we explored linkage disequilibrium of FVL with all known single nucleotide polymorphisms in a 1.5 MB region around the F5 gene with an R2 cutoff of 0.8. We sequenced exons of four candidate genes hypothesized to be linked to FVL in a subgroup of FVL carriers with extreme sperm count values. The animal studies consisted of never mated 15-18-week-old C57BL/J6 mice heterozygous and homozygous for FVL and wild-type mice. We compared spermatogenesis parameters (normalized internal genitalia weights, epididymis sperm content and sperm motility) between FVL and wild-type mice. MAIN RESULTS AND THE ROLE OF CHANCE: Human FVL carriers have a higher total sperm count than non-carriers, with an adjusted mean difference of 31 × 106 (95%CI 0.2-61.7; P = 0.048). Mice with the FVL mutation do not have increased spermatogenesis as compared to wildtype mice. None of the studied polymorphisms was in linkage disequilibrium, either in the public databases or in a subgroup of FVL carriers with extremely high sperm counts. LIMITATIONS, REASONS FOR CAUTION: The difference in total sperm count would benefit from confirmation in other cohorts. The finding of higher count in carriers was consistent however, with no heterogeneity between the cohorts. The lack of effect of murine FVL might suggest there is no direct causality. The exploratory efforts on genetic linkage do not rule out that the association is a reflection of FVL co-inheritance with a non-studied causative polymorphism. WIDER IMPLICATIONS OF THE FINDINGS: A high sperm count in FVL-carrying males contributes to understanding the high prevalence of this otherwise disadvantageous mutation. The findings might provide directions for future research on male fertility. STUDY FUNDING/COMPETING INTEREST(S): No conflicts of interest. Research was conducted with funding from the Netherlands Organisation for Scientific Research (NWO, VIDI innovative research grant 016.126.364 awarded to S. Middeldorp). The Danish cohort was supported by the Innovation Fund Denmark (InnovationsFonden, grant no. 14-2013-4), The Danish Ministry of Health and the Danish Environmental Protection Agency. TRIAL REGISTRATION NUMBER: Not applicable.

Filaggrin loss-of-function mutations, atopic dermatitis and risk of actinic keratosis: results from two cross-sectional studies.

BACKGROUND: Common loss-of-function mutations in filaggrin gene (FLG) represent a strong genetic risk factor for atopic dermatitis (AD). Homozygous mutation carriers typically display ichthyosis vulgaris (IV) and many have concomitant AD. Previously, homozygous, but not heterozygous, filaggrin gene mutations have been associated with squamous cell carcinomas. OBJECTIVE: The first objective was to examine the association between FLG mutations and actinic keratosis (AK). The second objective was to investigate the occurrence of AK in patients with IV and AD, respectively. METHODS: FLG mutation status in patients with AK was compared with controls from the general population. Furthermore, based on nationwide data from Danish registers, we compared the risk of AK in patients with IV, AD and psoriasis, respectively. RESULTS: The prevalence of homozygous FLG mutations was significantly higher in the AK group (n = 4, 0.8%) in comparison with the control group (n = 18, 0.2%), whereas the prevalence of heterozygous FLG mutations was lower. In hospital registry data, patients with AD exhibited an increased risk of AK than did psoriasis controls (adjusted OR 1.46; [95% CI 1.12-1.90]), whereas no difference in risk was observed between patients with IV and AD. CONCLUSIONS: This study indicates an increased susceptibility to AK in individuals with homozygous, but not heterozygous, FLG mutations and in patients with AD compared to psoriasis. Whether a reduction or absence of epidermal filaggrin could contribute to the susceptibility to AK in patients with IV and AD is unknown and additional research is needed to further explore this relationship.

Randomized clinical trial of prevention of seroma formation after mastectomy by local methylprednisolone injection.

BACKGROUND: Seroma formation, the most prevalent postoperative complication after mastectomy, is an inflammatory process that is potentially preventable via local steroid administration. This study investigated the effect of local steroid administration on seroma formation. METHODS: This was a double-blind randomized placebo-controlled intervention study of a single dose of 80 mg methylprednisolone versus saline on seroma formation after mastectomy. Patients were further classified according to the surgical axillary procedure: mastectomy with sentinel lymph node biopsy (M + SLNB) or mastectomy with level I-II axillary lymph node dissection (M + ALND). Treatments were administered into the wound cavity via the drain orifice following removal of the drain on the first day after surgery. The primary endpoint was seroma formation; secondary endpoints included the frequency of side-effects and complications. RESULTS: A total of 212 women scheduled for mastectomy for primary breast cancer were included. After M + SLNB, 32 (46 per cent) of 69 women developed a seroma in the methylprednisolone group, compared with 52 (78 per cent) of 67 in the saline group (P < 0.001). The mean cumulative seroma volume in the intention-to-treat population for the first 10 and 30 days was significantly lower in the methylprednisolone group (24 ml versus 127 ml in the saline group, and 177 versus 328 ml respectively) (P < 0.001). After M + ALND, similar proportions of patients developed a seroma in the methylprednisolone (35 of 37, 95 per cent) and saline (34 of 36, 94 per cent) groups, and methylprednisolone administration had no significant effect on seroma formation. No differences in infection rate were observed. CONCLUSION: Methylprednisolone administered into the wound cavity on the first day after M + SLNB exerted a highly significant preventive effect against seroma formation during the next 30 days. This effect was not seen in the M + ALND group. Future studies may clarify whether higher or repeated methylprednisolone doses increase the efficacy.

Filaggrin loss-of-function mutations and incident cancer: a population-based study.

BACKGROUND: Loss-of-function mutations in the filaggrin gene (FLG) could have opposing effects on cancer risk, as mutations are associated with both 10% higher serum vitamin D levels, which may protect against cancer, and with impaired skin barrier function, which may lead to higher cancer susceptibility. OBJECTIVES: To investigate the association of the FLG genotype and cancer types in four population-based cohorts. METHODS: A total of 13,376 individuals were genotyped for FLG mutations. Information on cancer was obtained from the Danish Cancer Registry. Persons with a history of cancer at baseline were excluded from prospective analyses. RESULTS: There were 1339 incident cancers (median follow-up 11·4 years). The hazard ratios (HRs) and 95% confidence intervals (CIs) for FLG mutation carriers vs. wild types were: for any cancer (HR 0·95, 95% CI 0·78-1·16), any cancer excluding nonmelanoma skin cancer (NMSC) (HR 1·05, 95% CI 0·84-1·31), head and neck cancer (HR 1·72, 95% CI 0·71-4·15), colorectal cancer (HR 0·82, 95% CI 0·44-1·52), bronchus and lung cancer (HR 1·34, 95% CI 0·77-2·33), breast cancer (HR 0·58, 95% CI 0·30-1·14), uterine cancer (HR 0·42, 95% CI 0·06-3·10), prostate cancer (HR 1·09, 95% CI 0·61-1·94), urinary cancer (HR 1·30, 95% CI 0·51-3·29), malignant melanoma (HR 1·03, 95% CI 0·41-2·58) and NMSC (HR 0·70, 95% CI 0·47-1·05). Among participants aged over 60 years at baseline, we found statistically significant lower risks of all cancers and NMSC among FLG mutation carriers. CONCLUSIONS: The only significant associations between FLG loss-of-function mutations and cancer were in subgroup analyses.

An elevated pro-inflammatory cytokine profile in multiple chemical sensitivity.

BACKGROUND: Multiple chemical sensitivity (MCS) is a medically unexplained condition characterized by reports of recurrent unspecific symptoms attributed to exposure to low levels of common volatile chemicals. The etiology of MCS is poorly understood, but dysregulation of the immune system has been proposed as part of the pathophysiology. OBJECTIVE: To compare plasma levels of cytokines in Danish MCS individuals with a healthy, sex- and age-matched control group. METHOD: Blood samples were obtained from 150 un-exposed MCS individuals and from 148 age- and sex-matched healthy controls. Plasma concentrations of 14 cytokines, chemokines and growth and allergen-specific IgE were measured. All participants completed a questionnaire including questions on MCS, psychological distress, morbidities and medication use at the time of the study. RESULTS: Plasma levels of interleukin-1ß, -2, -4, and -6 were significantly (P<0.001) increased in the MCS group compared with controls, tumor necrosis factor-α was borderline significantly (P=0.05) increased and interleukin-13 was significantly decreased (P<0.001). CONCLUSION: MCS individuals displayed a distinct systemic immune mediator profile with increased levels of pro-inflammatory cytokines and interleukin-2 and inverse regulation of Th2 associated cytokines interleukin-4 and interleukin-13 suggestive of low-grade systemic inflammation, along with a deviating Th2-associated cytokine response not involving IgE-mediated mechanisms.

The association between null mutations in the filaggrin gene and contact sensitization to nickel and other chemicals in the general population.

BACKGROUND: It was recently shown that filaggrin gene (FLG) null mutations are positively associated with nickel sensitization. We have hypothesized that histidine-rich filaggrin proteins in the epidermis chelate nickel ions and prevent their skin penetration and exposure to Langerhans cells. Furthermore, we have proposed that the low degree of genetic predisposition to nickel sensitization found by a Danish twin study was explained by a high prevalence of ear piercing among participants resulting in 'bypassing' of the filaggrin proteins. OBJECTIVES: To investigate the association between FLG null mutations and (nickel) contact sensitization. METHODS: A random sample of 3335 adults from the general population in Denmark was patch tested and genotyped for R501X and 2282del4 in the FLG gene. RESULTS: The combined carrier frequency of FLG null mutations was 8·1%. Nickel, fragrance and contact sensitization to at least one allergen were not associated with FLG null mutations. A crude analysis on women who did not have ear piercings revealed a positive association between FLG null mutations and nickel sensitization [8·3% vs. 2·4%; odds ratio (OR) 3·71, 95% confidence interval (CI) 0·73-18·96] as well as between FLG null mutations and allergic nickel dermatitis (8·3% vs. 1·3%; OR 6·75, 95% CI 1·17-38·91). FLG mutation status and atopic dermatitis were positively associated with neomycin or ethylenediamine sensitization. CONCLUSIONS: This study suggests that FLG null mutations may be a risk factor for the development of nickel sensitization. However, ear piercing was a much stronger risk factor in our general population and we could therefore identify a positive association only in women without ear piercings. Contact sensitization to specific chemicals is related to treatment exposure.

Surface immunoglobulin on B lymphocytes as a potential target for specific peptide ligands in chronic lymphocytic leukaemia.

With the aim of producing unique targets for malignant cells we have identified peptide ligands for the clonal surface immunoglobulin isolated from the B cells of a chronic lymphocytic leukaemia (CLL) patient. The peptides were identified from random-peptide phage-display libraries. The obtained ligands bound specifically to the surface of the target lymphocytes as well as to clonal immunoglobulin in lysate from the same cells. Peptide-based antigen mimotopes may have a future use in targeted therapy of CLL and other B-cell-derived malignancies displaying surface immunoglobulin.

Identification of patient-specific peptides for detection of M-proteins and myeloma cells.

We have taken advantage of the selection power of phage display technology to define specific peptide mimotopes that recognize individual M-proteins, isolated from patients with multiple myeloma. Preferred amino acid motifs of phages binding to M-proteins were identified in 6/9 patients investigated. Chemically synthesized peptides, corresponding to the phage-displayed peptide inserts, were used to verify the specificity of binding in competition assays. The peptides were able to bind to the M-proteins, as well as the myeloma cells, with high sensitivity and specificity. Employing simple immunological techniques, < 0.01 g/l of M-protein could be quantified, suggesting a novel way for monitoring minimal residual disease in the production of guidelines for adjusting or reintroducing conventional chemotherapy. The peptide mimotopes defined by this technology may be useful as tumour-specific targeting agents and as a tool for purging cells in autologous bone marrow transplantation.

Gastricsin-mediated proteolytic degradation of human seminal fluid proteins at pH levels found in the human vagina.

The proteolytic degradation of human seminal fluid proteins at acidic conditions has been investigated. Upon acidification to the pH level of the human vagina, autoproteolysis of most seminal fluid proteins occurred after 30 minute of incubation at 37 degrees C. The degradation was unaffected by inhibitors of serine, thiol, or metallo proteases, whereas pepstatin prevented any proteolysis. The proteins in seminal fluid depleted of the aspartic protease progastricsin did not degrade upon acidification. Readdition of the progastricsin restored the autoproteolytic ability of seminal fluid. Prostate-specific antigen, prostatic acid phosphatase, and Zn-alpha 2-glycoprotein are quickly degraded; albumin, transferrin, and lactoferrin are degraded more slowly. The low molecular weight fragments of semenogelin I and II and especially beta-microseminoprotein are somewhat resistant to proteolysis. These observations strongly suggest that the aspartic protease progastricsin is responsible for the autoproteolysis of seminal fluid proteins under acidic conditions. This suggests that the function of the enzyme is to degrade seminal fluid proteins deposited in the vagina; this in turn may decrease the antigenic load in the vagina and prevent immuno-infertility.