The Fc-mediated effector functions of a potent SARS-CoV-2 neutralizing antibody, SC31, isolated from an early convalescent COVID-19 patient, are essential for the optimal therapeutic efficacy of the antibody

Although SARS-CoV-2-neutralizing antibodies are promising therapeutics against COVID-19, little is known about their mechanism(s) of action or effective dosing windows. We report the generation and development of SC31, a potent SARS-CoV-2 neutralizing antibody, isolated from a convalescent patient. Antibody-mediated neutralization occurs via an epitope within the receptor-binding domain of the SARS-CoV-2 Spike protein. SC31 exhibited potent anti-SARS-CoV-2 activities in multiple animal models. In SARS-CoV-2 infected K18-human ACE2 transgenic mice, treatment with SC31 greatly reduced viral loads and attenuated pro-inflammatory responses linked to the severity of COVID-19. Importantly, a comparison of the efficacies of SC31 and its Fc-null LALA variant revealed that the optimal therapeutic efficacy of SC31 requires Fc-mediated effector functions that promote IFNγ-driven anti-viral immune responses, in addition to its neutralization ability. A dose-dependent efficacy of SC31 was observed down to 5mg/kg when administered before viral-induced lung inflammatory responses. In addition, antibody-dependent enhancement was not observed even when infected mice were treated with SC31 at sub-therapeutic doses. In SARS-CoV-2-infected hamsters, SC31 treatment significantly prevented weight loss, reduced viral loads, and attenuated the histopathology of the lungs. In rhesus macaques, the therapeutic potential of SC31 was evidenced through the reduction of viral loads in both upper and lower respiratory tracts to undetectable levels. Together, the results of our preclinical studies demonstrated the therapeutic efficacy of SC31 in three different models and its potential as a COVID-19 therapeutic candidate.

Studies on B Cells in the Fruit-Eating Black Flying Fox (Pteropus alecto)

The ability of bats to act as reservoir for viruses that are highly pathogenic to humans suggests unique properties and functional characteristics of their immune system. However, the lack of bat specific reagents, in particular antibodies, has limited our knowledge of bat's immunity. Here, we report a panel of cross-reactive antibodies against MHC-II, NK1.1, CD3, CD21, CD27, and immunoglobulin (Ig), that allows flow cytometry analysis of B, T and NK cell populations in two different fruit-eating bat species namely, Pteropus alecto and E. spelaea. Results confirmed predominance of T cells in the spleen and blood of bats, as previously reported by us. However, the percentages of B cells in bone marrow and NK cells in spleen varied greatly between wild caught P. alecto bats and E. spelaea colony bats, which may reflect inherent differences of their immune system or different immune status. Other features of bat B cells were investigated. A significant increase in sIg⁺ B cell population was observed in the spleen and blood from LPS-injected bats but not from poly I:C-injected bats, supporting T-independent polyclonal B cell activation by LPS. Furthermore, using an in vitro calcium release assay, P. alecto B cells exhibited significant calcium release upon cross-linking of their B cell receptor. Together, this work contributes to improve our knowledge of bat adaptive immunity in particular B cells.

Priming with high and low respiratory allergen dose induces differential CD4+ T helper type 2 cells and IgE/IgG1 antibody responses in mice

Sensitization of allergic patients normally takes place over several years and is the result of repeated exposure to low levels of allergen. Most mouse asthma models use a high dose of allergen administered over a short period. We have investigated the role of dose in the immune response to an inhaled respiratory allergen (Blomia tropicalis). We observed the effect of priming dose on the allergic response in mice intranasally immunized with low (0·5 μg) and high (50 μg) doses of B. tropicalis extract and killed 1 day after the last challenge. For both doses of allergen, T helper type 2 (Th2) cells and Th2 cytokines were evident as well as eosinophilic inflammation accompanied by mucus hyper-secretion. By contrast, IgE and IgG1 antibody responses were normally only detected at high-dose priming. To investigate the mechanism for these effects, we found group 2 innate lymphoid cells (ILC2s) were increased 48 hr after challenge in the low-dose-treated but not the high-dose-treated mice. Furthermore, we determined whether repeated low-dose exposure with different priming protocols could induce an antibody response. Repeated low-dose exposure to 0·5 μg three times weekly for 4 weeks (cumulative 6 μg) had the same effect as a shorter high-dose exposure (cumulative 80 μg) and increasing cumulative dose induced antibody responses. These data indicate that low doses of allergen are sufficient to prime Th2 cells and ILC2s, but insufficient to induce antibody responses. Cumulative exposure to small amounts of allergen induces both Th2 and antibody responses and may better reflect natural sensitization.

In silico analysis of the 5' region of the Vitamin D receptor gene: functional implications of evolutionary conservation

In recent years, the complexity of the 5' region of the Vitamin D receptor (VDR) gene has become apparent. Six exons, 1a-1f, lie upstream of the translation start codon in exon 2. Transcription has been reported beginning in exons 1f, 1a, 1d and 1c and alternative splicing can produce a large number of alternative mRNA transcripts. Exon 1d transcripts can code for two alternative proteins. This pattern of transcription produces several potential promoter regions. We have used a number of in silico tools to study the evolutionary conservation of the exon and promoter sequences of the 5' region. Those exons involved in the alternative VDR proteins, exons 1d and 1c, were well conserved from mouse and rat, unlike exons 1f, 1e and 1b which showed little homology. Exon 1a was also well conserved. Furthermore, 1a was shown to be within a strong CpG island and TraFac revealed a Sp1-MazR-Sp1-MazR cluster of transcription factor binding sites immediately upstream of exon 1a, a common motif in strong promoters. The promoter region upstream of 1f showed a highly conserved pattern of transcription factor binding sites and was also shown to be within a CpG island. No significant clusters of conserved sites were observed in the 1c promoter region, despite reports of 1c promoter activity.

Toxic epidermal necrolysis: current evidence, practical management and future directions

Toxic epidermal necrolysis (TEN) is a rare disorder characterized by extensive epidermal death. Almost all cases appear to be caused by an idiosyncratic drug reaction. Proposed pathogenic mechanisms are conflicting, and the evidence for the benefits of individual treatments is inadequate, and in some cases contradictory. The mortality rate remains high. We review the literature pertaining to the pathogenesis of TEN and drug reactions in general. The rationale for therapeutic interventions, together with reported evidence of efficacy, are considered. We present a composite model of TEN, based on previous work and suggested pathogeneses of TEN, mechanisms of drug reactions and reported cytotoxic lymphocyte (CTL) cytolytic pathways. In this system, TEN, like some other cutaneous drug eruptions, is an HLA class I-restricted, specific drug sensitivity, resulting in clonal expansion of CD8+ CTLs. Cytotoxicity is mediated by CTL granzyme and possibly death receptor (DR) ligand (DR-L), probably Fas ligand (FasL). Particular to TEN, there is then an amplification sequence involving further DR-L expression. FasL is likely to be particularly important but tumour necrosis factor (TNF) may well contribute, via the TNF receptor 1 (TNF-R1) death pathway. Alternatively, we suggest the possibility of upregulation of an antiapoptotic TNF-R1-nuclear factor kappaB pathway, which would proscribe treatments which downregulate this pathway. None of the published data on individual treatment efficacies is sufficiently strong to suggest a definitive single treatment. Currently a multifaceted regimen appears indicated, targeting various likely intermediary mechanisms, including elimination of residual drug, immunosuppression, inhibition of DR pathways, general antiapoptotic strategies, and aggressive supportive care. Particular attention has been directed at avoiding potential conflicts between different treatments and avoiding agents that theoretically might have a net proapoptotic rather than antiapoptotic effect. Nursing on a specialized unit is of paramount importance.

'Atrophic telogen effluvium' from cytotoxic drugs and a randomized controlled trial to investigate the possible protective effect of pretreatment with a topical vitamin D3 analogue in humans

BACKGROUND

Hair loss from cytotoxic drugs is classically ascribed to the loss of fractured hairs (anagen effluvium). Telogen hair loss has also been described but some authors have denied any effect on the hair cycle. There are conflicting reports on a protective effect of pretreatment with a vitamin D analogue on cytotoxic drug-induced hair loss in rodents.

OBJECTIVES

To investigate the process of cytotoxic hair loss and any protective effect on the hair of pretreatment with topical calcipotriol.

METHODS

Breast cancer patients who were about to receive cycles of chemotherapy with cyclophosphamide 600 mg m(-2), methotrexate 40 mg m(-2) and 5-fluorouracil 600 mg m(-2) were recruited and randomized to receive calcipotriol scalp solution 50 microg mL(-1) or vehicle. The solution was applied twice daily from 4 days prior to chemotherapy and continued for 14 days in each treatment cycle. Shed, plucked and cut hairs were sampled. Absolute shed rates, the proportion of major hair types, the presence of proximal hair shaft changes, regrowth (using the new anagen hair count) and hair density were assessed.

RESULTS

Ten patients receiving calcipotriol and 14 receiving vehicle completed three treatment cycles and nine from both groups completed six cycles. There was no detectable effect of calcipotriol on the proportion of patients experiencing minimal hair loss from chemotherapy, shed rates, plucked telogen and fractured hair counts, the morphology of shed and plucked hair, hair regrowth or hair density. Combining results of the treatment groups, there was a large variation in the impact of chemotherapy on hair loss, from total loss in five patients to no obvious loss in five. Excluding the latter, during chemotherapy shed telogen hairs (mean 81% of shed hairs) predominated over fractured (12%) and anagen hairs (6%) (P = 0.0002). The major pathological change was proximal hair shaft tapering, baseline mean 3% of shed hairs rising to 48% (P = 0.0005) during treatment, and there was a consequent decrease in normal telogen hairs, baseline mean 98% of all telogen hairs falling to 55% (P = 0.0005) during treatment. The pathological tapered telogen hairs had normal or small, sometimes diminutive, bulbs. Fracturing of hairs with diminutive bulbs produced typical 'exclamation mark' hairs.

CONCLUSIONS

The cardinal effects of cytotoxic drugs found in this study were tapering of the proximal hair shaft and premature entry of the follicle into telogen, conflicting with the conventional view that affected hair follicles continue in anagen. There was a resulting effluvium of a mixture of tapering telogen hairs and fractured hairs. As entry into telogen is an integral part of the process, cytotoxic hair loss may be regarded as a variant of the conventional 'telogen effluvium' and we propose the term 'atrophic telogen effluvium'. There was no obvious protective effect on the hair loss of prior treatment with topical calcipotriol.

Vitamin D receptor gene polymorphisms, particularly the novel A-1012G promoter polymorphism, are associated with vitamin D3 responsiveness and non-familial susceptibility in psoriasis

Psoriasis is a genetically determined disease characterized by hyperproliferation and disordered maturation of the epidermis. Th1 lymphocytes are implicated in its pathogenesis. The vitamin D receptor (VDR) is a candidate modifying gene, having immunosuppressive effects and being involved in anti-proliferative and pro-differentiation pathways in keratinocytes. There is suggestive evidence that the A allele of the A-1012G polymorphism is associated with down-regulation of the Th1 response, via GATA-3. The F and T alleles of Fok1 and Taq1 have been associated with increased VDR activity. The present study aimed to test the hypothesis that the A allele of A-1012G is protective for occurrence and severity of psoriasis and enhances therapeutic response to vitamin D analogues and that these effects would be additive to those of Fok1 and Taq1. The study group comprised 206 psoriasis patients who had received topical calcipotriol treatment and 80 controls. There was no significant linkage disequilibrium between any pair of the three polymorphic sites (P=0.3-0.8). The A, F and T alleles were positively associated with calcipotriol response: AA genotype (compared to AG/GG), odds ratio (OR)=2.18 (P=0.04); TT, OR=1.97 (P=0.03); AAFF genotype combination, OR=4.11 (P=0.03); AATT, OR=5.64 (P=0.005); and FFTT, OR=3.22 (P=0.01). Comparing patients without, to patients with, a family history of psoriasis, the A allele was under represented (P=0.01) and the AAFF genotype combination even more so (compared to residual genotypes) (OR=0.24; P=0.005). AAFF was also under-represented in patients without a family history compared to controls (OR=0.31; P=0.04). There were no associations of family history with Fok1 and Taq1. There were no associations of severity of psoriasis with any polymorphism. In conclusion, the A-1012G, Fok1 and Taq1 VDR polymorphisms were associated with response to calcipotriol. A-1012G and Fok1 were associated with susceptibility to non-familial psoriasis.

A novel polymorphism in the 1A promoter region of the vitamin D receptor is associated with altered susceptibilty and prognosis in malignant melanoma

The association of Taq 1 and Fok 1 restriction fragment length polymorphisms of the vitamin D receptor with occurrence and outcome of malignant melanoma (MM), as predicted by tumour (Breslow) thickness, has been reported previously. We now report a novel adenine–guanine substitution −1012 bp relative to the exon 1a transcription start site (A-1012G), found following screening by single-stranded conformational polymorphism of this promoter region. There was a total of 191 MM cases , which were stratified according to conventional Breslow thickness groups, cases being randomly selected from each group to form a distribution corresponding to the known distribution of Breslow thickness in our area, and this population (n=176) was compared to 80 controls. The A allele was over-represented in MM patients and, with GG as reference, odds ratio (OR) for AG was 2.5, 95% confidence interval (CI) 1.1–5.7, (P=0.03) and AA 3.3, CI 1.4–8.1, (P=0.007). The outcome was known in 171 of 191 patients and the A allele was related to the development of metastasis, the Kaplan–Meier estimates of the probability of metastasis at 5 years being: GG 0%; AG 9%, CI 4–16%; AA 21%, CI 12–36%; (P=0.008), and to thicker Breslow thickness groups (P=0.04). The effect on metastasis was independent of tumour thickness and A-1012G may have predictive potential, additional to Breslow thickness. Neither the Fok 1 nor Taq 1 variants (f and t) were significantly related to the development of metastasis, although there was a strong relationship of fftt with the thickest Breslow thickness group (P=0.005). There was an interaction between the A-1012G and Fok 1 polymorphisms (P=0.025) and the Fok 1 variant enhanced the effect of the A allele of the A-1012G polymorphism on metastasis, the probability of metastasis for AAff at 5 years follow-up being 57%, CI 24–92%.

Fatal toxic epidermal necrolysis: A complication of vancomycin treatment for an infected hip arthroplasty

The incidence of MRSA or MRSE type infections involving hip prostheses is increasing. Treatment often involves removal of the prosthesis followed by a defined period of antibiotic treatment, prior to insertion of a second prosthesis. Vancomycin is often used in this setting. We report a fatal case of toxic epidermal necrolysis (TEN) in a patient receiving vancomycin following a first stage revision hip replacement. With the increasing use of vancomycin in revision arthroplasty cases, knowledge of this rare but commonly fatal side effect is important so that if it occurs, rapid and appropriate treatment may be commenced. (Hip International 2004; 14: 58-61).

Adaptive immunity to nontypeable Haemophilus influenzae

Nontypeable Haemophilus influenzae (NTHi) colonizes the upper respiratory tract of most healthy people and is also a major cause of infection in chronic obstructive lung disease. The immune response to this bacterium has not been well characterized. We tested the hypothesis that recurrent airway infection with NTHi may be associated with nonclearing adaptive immunity. Study subjects were healthy control subjects and patients with idiopathic bronchiectasis who had severe chronic infection with H. influenzae. We established that all subjects in both groups had detectable antibody to NTHi, suggesting that most normal people have developed an adaptive immune response. To characterize the nature of the immune response, we measured antigen-specific production of T helper cell cytokines and CD40 ligand by flow cytometry and immunoglobulin subclass levels in peripheral blood. We found that normal control subjects made Th1 response to NTHi with distinct CD40 ligand production. In contrast, subjects with bronchiectasis had predominant production of Th2 cytokines, decreased expression of CD40 ligand, and different immunoglobulin G subclass production. Therefore, chronic infection with NTHi in bronchiectasis is associated with a change in adaptive immunity that may be important in the pathogenesis of bronchial infection.

Comparison of diagnostic accuracy for cutaneous malignant melanoma between general dermatology, plastic surgery and pigmented lesion clinics

BACKGROUND

Since the 1980s there have been dedicated pigmented lesion clinics (PLCs) in the U.K. Important considerations when comparing the efficacy of the PLC with other referral clinics include diagnostic accuracy.

OBJECTIVES

To compare the false-negative rate of clinical diagnosis (FNR) in the PLC with that in the other clinics of primary referral of malignant melanoma (MM) in the same geographical area. We have previously shown that certain clinical features are risk factors for diagnostic failure of MM. A further aim of this study was to correct for any differences in frequency of these factors in the melanoma populations between clinics and to estimate the false-positive diagnostic rate (FPR) in the PLC.

METHODS

To compare the FNR between clinics, the case notes of all patients presenting with histologically proven cutaneous MM in Leicestershire between 1987 and 1997 were examined retrospectively. A false-negative diagnosis was defined as documentation of another diagnosis and/or evidence in the case notes that the diagnosis was not considered to be MM. The FNR was estimated as the number of false-negative clinical diagnoses/number of true-positive histological diagnoses. To estimate the diagnostic FPR, which was defined as the number of false-positive clinical diagnoses of MM/total number of positive clinical diagnoses, in the PLC, the outcome of 500 consecutive patients attending the PLC was surveyed.

RESULTS

The case notes of 731 patients were available, of whom approximately two-thirds initially attended the PLC, one-fifth the General Dermatology clinics (D) and the remainder were divided approximately equally (one-twentieth each) between Plastic Surgery clinics (P), other clinics (O) and the surgery of the general practitioner (GP). The last was regarded as the primary referral clinic if the lesion were excised there prior to any referral. The FNR was lowest for the PLC, at 10%, compared with 29% (D), 19% (P), 55% (O) and 54% (GP) (P < 0.0001). Lesions with risk factors for diagnostic failure were under-represented in the PLC (P < 0.0001), the mean frequencies of the risk factors being 20% (PLC), 25% (D), 22% (P), 31% (O) and 30% (GP). Differences were not large but still could partially explain the lower FNR of the PLC. However, when the FNR was estimated for lesions exhibiting each of these risk factors, the PLC was found to have the lowest rate in every case (PLC vs. all clinics combined, P = 0.04 to P < 0.0001). The mean FNR for the risk factors combined was 18% (PLC), 45% (D), 50% (P), 68% (O) and 71% (GP). Also on logistic multivariable analysis of the PLC vs. all the other clinics on FNR and the above factors, the higher FNR of the other clinics retained significance (odds ratio 5.9, P < 0.0001). In the 500 patients surveyed separately in the PLC, the MM pick-up rate on biopsy was 32% and the diagnostic FPR was 41%.

CONCLUSIONS

The FNR of MM was lower in the PLC than in the other clinics, while the pick-up rate for MM on biopsy and the FPR were acceptably low.

A follow-up study to investigate the efficacy of initial treatment of lentigo maligna with surgical excision

Recurrence rates following conventional surgery for lentigo maligna (LM) are reported to be between 7% and 15%. However, the studies are few, contain small numbers of patients and have relatively short follow-up. The principle aim of this study was to determine the efficacy of conventional surgery for LM in a large unbiased sample of all LM presenting in a defined geographical area. All LM cases occurring in Leicestershire between 1987 and 1996 were identified. Data were gathered from case notes, general practitioners and the Office for National Statistics (for any mortality data) and patients were invited to attend for examination. There were 89 evaluable patients treated with primary excision, representing the largest reported series to date. There was a false positive rate for diagnostic biopsy for LM (when the correct diagnosis was lentigo maligna melanoma, LMM) of 5% (95% confidence interval, CI: 1% to 14%). The initial excision was histologically incomplete in 9% (4% to 17%) of cases. In completely excised lesions (n=81) the observed recurrence rate was 20% (CI: 12% to 30%) at a mean follow-up of 42 months, which is similar to previous reports. However, Kaplan-Meier analysis yielded an estimated probability of recurrence of 31% (CI: 19% to 50%); time to relapse was up to 66 months. The age and sex of the patient and the site of the lesion were not associated with outcome, but, surprisingly, smaller lesions were associated with incomplete excision and recurrence. Fifteen current lesions were excised with similar success rates: the incomplete re-excision rate was 7% (CI: 0.2% to 32%) and the recurrence rate was 31% (CI: 12% to 83%) at 28 months. The estimated rate of transformation to LMM after initial surgical treatment was 1.5% (CI: 0.3% to 8%), and LMM was not the cause of death in any patient. These recurrence rates following complete primary excision and re-excision following recurrence were high compared with general expectations, which is largely the result of the method of analysis and the long follow-up. The high rate calls into question the accuracy of the routine histological assessment of clearance. The development of LMM was rare following surgery.

Safety and efficacy of combined high-dose treatment with calcipotriol ointment and solution in patients with psoriasis

BACKGROUND

In the vast majority of psoriatic patients, psoriatic lesions are localised on the body as well as on the scalp. Therefore, safety data on the combined use of calcipotriol in lotion and calcipotriol in ointment are needed.

OBJECTIVE

This study investigated the effect of high-dose treatment with a combination of calcipotriol ointment and scalp solution on calcium metabolism, indices of bone turnover and PASI in patients with extensive psoriasis.

METHODS

Following a 2-week wash-out period, 88 patients were randomised to 4 weeks of treatment with either calcipotriol ointment/scalp solution (80-100 g/week and 30-50 ml/week, respectively; n = 41) or with a dithranol/tar regimen (n = 47). Patients were seen at weeks 1, 2 and 4 during treatment and 1 week following cessation of treatment.

RESULTS

No significant differences at the end of treatment were found between the 2 groups with respect to 24-hour urinary excretion of calcium (expressed as calcium/creatinine ratio), phosphate or pyridinoline, serum concentrations of calcium (albumin corrected), creatinine, phosphate, parathyroid hormone, 25-hydroxyvitamin D(3), 1,25-dihydroxyvitamin D(3), osteocalcin, alkaline phosphatase (total and bone-specific iso-enzymes) or 1-collagen telopeptide. At the end of treatment, the psoriasis area and severity index had decreased by 57.4% in the calcipotriol group and by 36.1% in the dithranol/tar group (p = 0.004). Investigators' and patients' assessments of overall efficacy also favoured treatment with calcipotriol (p < 0.001).

CONCLUSION

The combined use of calcipotriol ointment/scalp solution did not affect the indices of calcium metabolism or bone turnover and was significantly more effective than dithranol/tar in reducing disease severity and extent in patients with extensive psoriasis.

Vitamin D and systemic cancer: is this relevant to malignant melanoma?

1,25-dihydroxyvitamin D3[1,25(OH)2D3] is a well-known potent regulator of cell growth and differentiation and there is recent evidence of an effect on cell death, tumour invasion and angiogenesis, which makes it a candidate agent for cancer regulation. The classical synthetic pathway of 1,25(OH)2D3 involves 25- and 1 alpha-hydroxylation of vitamin D3, in the liver and kidney, respectively, of absorbed or skin-synthesized vitamin D3. There is recent focus on the importance in growth control of local metabolism of 1,25(OH)2D3, which is a function of local tissue synthetic hydroxylases and particularly the principal catabolizing enzyme, 24-hydroxylase. The classical signalling pathway of 1,25(OH)2D3 employs the vitamin D nuclear receptor (VDR), which is a transcription factor for 1,25(OH)2D3 target genes. Effects of this pathway include inhibition of cellular growth and invasion. Cytoplasmic signalling pathways are increasingly being recognized, which similarly may regulate growth and differentiation but also apoptosis. 1,25(OH)2D3 has a major inhibitory effect on the G1/S checkpoint of the cell cycle by upregulating the cyclin dependent kinase inhibitors p27 and p21, and by inhibiting cyclin D1. Indirect mechanisms include upregulation of transforming growth factor-beta and downregulation of the epidermal growth factor receptor. 1,25(OH)2D3 may induce apoptosis either indirectly through effects on the insulin-like growth receptor and tumour necrosis factor-alpha or more directly via the Bcl-2 family system, the ceramide pathway, the death receptors (e.g. Fas) and the stress-activated protein kinase pathways (Jun N terminal kinase and p38). Inhibition of tumour invasion and metastasis potential has been demonstrated and mechanisms include inhibition of serine proteinases, metalloproteinases and angiogenesis. The lines of evidence for an effect of vitamin D3 in systemic cancer are the laboratory demonstration of relevant effects on cellular growth, differentiation, apoptosis, malignant cell invasion and metastasis; epidemiological findings of an association of the occurrence and outcome of cancers with derangements of vitamin D3/1,25(OH)2D3 and the association of functional polymorphisms of the VDR with the occurrence of certain cancers. In addition, vitamin D3 analogues are being developed as cancer chemotherapy agents. There is accumulating evidence that the vitamin D3/1,25(OH)2D3/VDR axis is similarly important in malignant melanoma (MM). MM cells express the VDR, and the antiproliferative and prodifferentiation effects of 1,25(OH)2D3 have been shown in cultured melanocytes, MM cells and MM xenografts. Recently, an inhibitory effect on the spread of MM cells has been demonstrated, low serum levels of 1,25(OH)2D3 have been reported in MM patients and the VDR polymorphisms have been shown to be associated with both the occurrence and outcome of MM. The relationship between solar irradiation and MM is more complex than for the systemic cancers. As in other cancers, there is evidence of a protective effect of vitamin D3 in MM, but ultraviolet radiation, which is a principal source of vitamin D3, is mutagenic. Further work is necessary on the influence of serum vitamin D3 levels on the occurrence and prognosis of MM, the effects of sun protection measures on serum vitamin D3 levels in temperate climates and epidemiological studies on geographical factors and skin type on the prognosis of MM. Meanwhile, it would seem mandatory to ensure an adequate vitamin D3 status if sun exposure were seriously curtailed, certainly in relation to carcinoma of breast, prostate and colon and probably also MM.

The importance of accurate dosage of topical agents: a method of estimating involved area and application to calcipotriol treatment failures

Little attention is given to accurate dosage of topical medication which is a potential source of side-effects and treatment failure. There are studies on the dosage for 'sparing' application relevant to topical steroids but not for 'liberal' application. Though calcipotriol is a first line topical treatment for psoriasis, approximately one-third of patients do not respond adequately. The aims of the present study were to define liberal dosage, to develop a method of calculation of area of involved skin and to evaluate the efficacy of calcipotriol in optimized liberal dosages, based on preliminary studies, in calcipotriol treatment failures. Weight/unit area of ointment and cream base, constituting liberal application, was determined in six normal volunteers. The area of psoriatic involvement in 24 calcipotriol non-responders was estimated by a 'fill-up' method and a modified 'hand' method. The results of the two methods were similar (Pearson correlation coefficient 0.68, P < 0.0001) but the 'hand' method proved easier in use and was the preferred method for the rest of the study. The patients applied calcipotriol at their accustomed rates for at least 2 weeks and then at the calculated liberal rates, using cream in the morning and ointment at night, for 4 weeks. The efficacy measures were Psoriasis Area and Severity Index (PASI) (primary measure), a four-point efficacy score and a visual analogue scale. As a result of the preliminary study and the actual amounts used by the patients in the psoriasis treatment study reported below, liberal application has been defined as 50 g/m2 per application for ointment base and 40 g/m2 per application for cream. At this dosage, an average individual would use approximately 100 g of medication/week to treat 10% of the body surface. During the 4-week treatment study, the psoriasis patients used an average of 39 g (SD 17 g)/m2 per application of cream and 52 g (SD 13 g)/m2 per application of ointment. All efficacy measures showed marked improvement (P < 0.0001). The frequency distribution of the PASI reduction defined responsive (70% of patients) and poorly responsive groups (30%), with mean PASI reduction of 60% and 17%, respectively.

Necrobiotic xanthogranuloma with two monoclonal paraproteins and no periorbital involvement at presentation

A patient with necrobiotic xanthogranuloma is presented to highlight the clinico-pathological features of this rare condition which must be differentiated from atypical necrobiosis lipoidica. The patient is unusual in that he has two associated monoclonal paraproteins and did not have periorbital involvement at presentation.

Clinical correlates of Breslow thickness of malignant melanoma

BACKGROUND

Breslow thickness is a major predictor of prognosis in cutaneous malignant melanoma (MM) and patients continue to present with thick lesions, which have a poorer prognosis.

OBJECTIVES

To investigate correlations of Breslow thickness with demographic variables, tumour site, clinical features, false negative diagnostic rate and clinic of primary referral.

METHODS

Data were obtained from the records of 738 patients with histologically diagnosed cutaneous MM. Tumours included were in situ and invasive MM and lentigo maligna melanoma. In view of the skewed distribution of MM thickness, categories of MM thickness were used for analysis, using the commonly applied cut-offs of 0.75, 1.5 and 3.5 mm. The variables investigated were particularly associated with changes in the proportion of the thickest group, 'thick' MMs. The proportion of this thickness category is proposed as an appropriate and sensitive variable for the investigation of correlations with MM thickness. Thickness >/= 1.5 mm has also been considered in view of its prognostic significance.

RESULTS

Results were similar for the two thickness groups, but more significant for the thick group. The previously described correlations of tumour thickness and increasing age (P < 0.00001) and location on head and neck (P = 0.0002), together with the independence of these variables, have been confirmed. The correlation with male gender was also confirmed but this was weak (P = 0.05). Novel findings were correlations of Breslow thickness with all features of the seven-point checklist (P varying from P = 0.01 to P < 0.00001) and tumour elevation (P < 0.00001). In general in the seven-point checklist, the absence of the major features (except variation in size) (P < 0.00001) and presence of minor features (except altered sensation) (P varying from P = 0.004 to P < 0.00001) were strongly associated with thick MMs. These results for tumour thickness are a further argument for retention of the minor features of the seven-point checklist. False negative diagnosis was found to be correlated with tumour thickness (P < 0.02) but this relationship was lost on multivariate analysis with inclusion of the clinical features. MM thickness was highly correlated with primary referral clinic (P < 0.00001). Only approximately 8% of MMs presenting to the Pigmented Lesion Clinic (PLC) were thick, while the proportion presenting to general dermatology was about three times greater and to plastic surgery about five times greater. This was maintained on multivariate analysis, including all other variables and, therefore, there must be other determining factors of referral not examined in the study. Conclusion MM thickness is associated with increasing age, male gender, location on the head and neck, all features of the seven-point checklist, tumour elevation and referral to the PLC. It is important to investigate further the reasons for general practitioner referral of different thickness MM to different types of clinic, as referral to clinics other than the PLC results in delay in the first hospital appointment, and it is now apparent that thicker lesions are disproportionately affected.

The efficacy, safety and tolerance of calcitriol 3 microg/g ointment in the treatment of plaque psoriasis: a comparison with short-contact dithranol

OBJECTIVE

A comparison of efficacy, safety and tolerance of a twice-daily application of calcitriol 3 microg/g ointment with dithranol cream.

METHODS

The study was an 8-week, prospective, randomised, open, parallel-group trial with 114 patients. Subjects received either 3 microg/g calcitriol ointment (twice daily) or 0. 25-2% dithranol cream (once daily for 30 min). Results were measured using global improvement, global severity, PASI, quality of life (QOL) and Psoriasis Disability Index scores. Safety was determined from reports of adverse events and blood chemistry analysis.

RESULTS

At final assessment, calcitriol and dithranol were comparably efficacious. Skin irritation was reported by 5% of calcitriol and 72% of dithranol patients. Patients rated QOL and overall acceptability of calcitriol more highly.

CONCLUSIONS

Twice-daily calcitriol ointment (3 microg/g) is equally effective as a once-daily, short-contact dithranol regimen. However, calcitriol is better tolerated than dithranol, and provides a better QOL and a greater patient acceptability.

Induction and excretion of ultraviolet-induced 8-oxo-2'-deoxyguanosine and thymine dimers in vivo: implications for PUVA

Molecular epidemiology has linked ultraviolet-induced DNA damage with mutagenesis and skin carcinogenesis. Ultraviolet radiation may damage DNA in one of two ways: either directly, leading to lesions such as cyclobutane thymine dimers (T<>T), or indirectly, via photosensitizers that generate free radical species that may ultimately produce such oxidative lesions as 8-oxo-2'-deoxyguanosine. We report the results of a pilot, case control study in which seven, healthy, human volunteers (skin type II; aged 23-56 y; three male, four female) received a suberythemal dose of whole body irradiation from ultraviolet-A-emitting fluorescent tubes used in psoralen plus ultraviolet A therapy. First void, mid-stream urine samples were collected pre-exposure and daily postexposure, for up to 13 d. Analysis of urinary 8-oxo-2'-deoxyguanosine and cyclobutane thymine dimers was by competitive enzyme-linked immunosorbent assay (interassay coefficient of variation < or = 10%) and compared with a matched, control group of unirradiated individuals. A maximal increase in levels of urinary 8-oxo-2'-deoxyguanosine was seen 4 d post-ultraviolet exposure. A subsequent reduction was noted, before finally returning to baseline. Similarly, cyclobutane thymine dimer levels peaked 3 d postexposure, before returning to baseline. In contrast to the 8-oxo-2'-deoxyguanosine analysis, however, a second peak was noted at days 9-11, before again returning to baseline. This is the first report examining urinary 8-oxo-2'-deoxyguanosine and cyclobutane thymine dimers following ultraviolet exposure of healthy human subjects. This work illustrates the induction and time course for excretion of ultraviolet-induced lesions, perhaps alluding to repair and ultimately offering the potential to define psoralen plus ultraviolet A dosage regimes in terms of minimizing DNA damage and hence cancer risk.

Treatment of psoriasis with oral liarozole: a dose-ranging study

BACKGROUND

Liarozole is an inhibitor of the metabolism of all-trans-retinoic acid. Systemic administration increases tissue levels of this endogenous retinoid and has been reported to improve psoriasis in an open, uncontrolled study.

OBJECTIVES

A multicentre, double-blind, placebo-controlled, dose-ranging study was therefore undertaken to determine the lowest effective oral dose of liarozole in the treatment of psoriasis vulgaris.

PATIENTS/METHODS

Adult male and postmenopausal female patients requiring systemic treatment for psoriasis were randomized to receive placebo or liarozole at total daily doses of 50 mg, 75 mg or 150 mg for 12 weeks. The daily doses were each divided into two equal (morning and evening) doses. Response was assessed using an eight-point global scale to assess improvement and by monitoring the Psoriasis Area and Severity Index (PASI). The primary end-point was the proportion of subjects in each treatment group demonstrating 'marked improvement' or better as assessed on the eight-point scale. The tolerability of the treatment was assessed by recording mucocutaneous effects of retinoids and all adverse events. Biochemical and haematological monitoring were also performed.

RESULTS

One hundred and thirty-nine subjects were randomized (118 male and 21 female) and 116 completed the study. A marked improvement or better response was observed in 6% of subjects on placebo, 18% on liarozole 50 mg, 11% on 75 mg and 38% on 150 mg. Only in the 150-mg group was the response rate significantly different to placebo (P < 0.001). Over the treatment period the mean PASI changed from 15.9 to 15.4 on placebo, from 17.4 to 13.8 on liarozole 50 mg, from 17.5 to 14.5 on 75 mg and from 15.8 to 8.8 on 150 mg. Again, only in the group receiving 150 mg was the response significantly better than placebo (P < 0.001). Liarozole was generally well tolerated. Mucocutaneous retinoid effects were generally infrequent and mild. Five subjects were withdrawn from treatment as a result of adverse events that may have been treatment related. These events were abnormalities of liver enzymes in two cases, an episode of erythema multiforme (in a patient receiving placebo), an allergic reaction in one and a rash accompanied by deterioration of the psoriasis in another. There was mild elevation of triglycerides in the groups receiving liarozole 75 mg and 150 mg daily. In males, the serum luteinizing hormone and testosterone levels rose significantly in all the active treatment groups.

CONCLUSIONS

The data confirm that liarozole is an effective treatment for psoriasis and indicate that the lowest effective dose is 75 mg twice daily. The drug seems generally to be well tolerated.

Vitamin D receptor polymorphisms are associated with altered prognosis in patients with malignant melanoma

Calcitriol [1,25(OH)2D3], the hormonal derivative of vitamin D3, is an antiproliferative and prodifferentiation factor for several cell types, including cultured melanocytes and malignant melanoma (MM) cells. Several polymorphisms of the vitamin D receptor (VDR) gene have been described including a FokI RFLP in exon 2, BsmI, and ApaI polymorphisms in intron 8 and an adjacent TaqI RFLP in exon 9. Alterations in vitamin D/1,25(OH)2D3 levels and polymorphisms of the VDR have been shown to be associated with several systemic malignancies. We hypothesize that polymorphism in this gene may be associated with altered susceptibility and outcome in patients with MM. A hospital-based case-control study, using 316 MM cases and 108 controls, was used to assess associations with MM susceptibility. Breslow thickness, the most important single prognostic factor in MM, was used as the outcome measure. Polymorphisms at the FokI and TaqI restriction sites were determined using PCR-based methods. Polymorphism at the FokI, but not TaqI, RFLP was associated with an altered risk of MM (P = 0.014). More importantly, variant alleles were associated with increased Breslow thickness. Thus, homozygosity for variant alleles at both RFLP (ttff genotype combination) was significantly associated with thicker tumors. (> or = 3.5 mm; P = 0.001; odds ratio = 31.5). Thus, polymorphisms of the VDR gene, which would be expected to result in impaired function, are associated with susceptibility and prognosis in MM. These data suggest that 1,25(OH)2D3, the ligand of the VDR, may have a protective influence in MM, as has been proposed for other malignancies.

Urinary thymine dimers and 8-oxo-2'-deoxyguanosine in psoriasis

Psoralen in conjunction with UVA (PUVA) is perhaps the most effective treatment for psoriasis. It is, however, a risk factor for skin cancer in these patients and there is a need to develop non-invasive assays reflective of treatment-induced DNA damage. We report here the assessment of two important lesions, thymine dimer (T<>T) and 8-oxo-2'-deoxyguanosine (8-OHdG), in the urine of psoriasis patients. It was found that, once corrected for urine concentration, the psoriatic group had significantly higher (P<0. 0001) urinary levels of thymine dimers compared to the control group. No significant differences in urinary 8-OHdG levels were noted between the psoriatic, atopic dermatitis and control groups. Therefore biomonitoring of therapy from the very start with this simple and non-invasive assay could perhaps be an effective measure of the risk involved with the treatment allowing optimization for minimal-risk therapy.

Cytochrome P450 CYP2D6 genotypes: association with hair colour, Breslow thickness and melanocyte stimulating hormone receptor alleles in patients with malignant melanoma

We previously identified associations between polymorphism in the cytochrome P450 CYP2D6 gene and outcome in several cancers. We have now examined the hypothesis that homozygosity for the mutant alleles, CYP2D6*4 and CYP2D6*3, is associated with susceptibility and outcome in malignant melanoma. Outcome was assessed by Breslow thickness. We first confirmed previous reports that these mutant alleles are associated with increased susceptibility to malignant melanoma. For example, the frequency of homozygosity for CYP2D6*4 was significantly greater (P = 0.006, chi-squared 1 d.f. = 7.4, odds ratio 2.2, 95% confidence interval 1.2, 3.9) in cases (9.1%) than in control individuals (4.3%). The frequency of homozygosity for the mutant alleles was next examined in the malignant melanoma cases grouped on the basis of characteristics associated with malignant melanoma risk. Homozygosity was significantly more common (P = 0.038) in cases with red/blonde hair than in those with brown/black hair. We found no associations between the CYP2D6 genotype and sex, skin type or eye colour. The possible association of CYP2D6 with outcome was assessed by comparing genotype frequencies in patients with tumours of Breslow thickness < 1.5 mm with those whose tumours were > or = 1.5 mm. In patients with red/blonde, but not brown or black hair, homozygosity for CYP2D6*4 was significantly associated with thicker lesions in a multivariate model (P = 0.036). We further examined the association of CYP2D6*4 homozygosity with red/blonde hair by classifying patients on the basis of homo- or heterozygosity for wild-type or val92met, asp294his or asp84glu melanocyte stimulating hormone receptor (MC1R) alleles. None of the nine patients with brown/black hair with the asp294his allele were homozygotes for CYP2D6*4. By contrast, in the patients with red/blonde hair, three of five cases with asp294his were homozygotes for the mutant CYP2D6 allele. The difference in the frequency of CYP2D6*4 homozygotes in the red/blonde cases with wild-type MC1R alleles compared with those with asp294his was significant (exact P = 0.029). No associations between val92his or asp84glu and CYP2D6 alleles were identified.

False negative clinical diagnoses of malignant melanoma

The false negative rate for the clinical diagnosis (FNR) for malignant melanoma is reported to be of the order of 20-50%. The aim of this study was to investigate possible predictor variables for FNR, with particular reference to the features and score of the seven-point check-list within the total population (778) of histologically proved malignant melanomas presenting in Leicestershire between 1982 and 1996. The FNR was 18.5%. The check-list would have failed as a referral indication in only 0.8-1. 1% of the lesions. The major check-list features occurred more commonly than the minor features, excepting size >/= 7 mm, confirming the diagnostic importance of the major criteria. The FNR was unaffected by age or sex. More rarely involved sites had higher rates (31-42%), and the face was a particularly difficult diagnostic site. Clinical features of lesions associated with a higher FNR were lack of irregular pigmentation and shape, altered sensation, the presence of inflammation and size < 7 mm. The FNR was inversely related to the total score and major feature score, but directly related to the minor score. The minor features, in addition to the major features, are potentially valuable in avoiding false negative diagnoses and we suggest their retention as part of the check-list. There was only one patient, in whom the diagnosis of melanoma was initially missed and who was not biopsied on presentation to hospital, who re-presented after 1 year. However, the study illustrates the importance of avoiding a false negative diagnosis as there was marked delay in the excision of such lesions.

The size and form of the medulla of human scalp hair is regulated by the hair cycle and cross-sectional size of the hair shaft

Hairs were sampled from long-haired Caucasian females, and cross-sectional measurements were performed using a rotating profile method at fixed humidity (100%). The effect of the hair cycle on medullation was investigated by examining medulla size and form along the lengths of anagen and telogen terminal hairs and also from a composite model of the entire medulla, as produced from a full cycle's growth, by amalgamating the results from the anagen and telogen hairs. The effect of hair shaft cross-sectional size on medullation has been investigated by controlling any effect of the hair cycle on terminal hairs and by use of the maximal medulla size in short, fine (vellous) hairs from the same subjects. All terminal hairs were medullated for the majority of their lengths. The presence and size of the medulla, in terminal hairs, was profoundly affected by the hair cycle. It was largest early in anagen, where the medulla minor axis, major axis and cross-sectional area represented about 26%, 23% and 7% of the corresponding whole hair shaft parameters (at 100% humidity). The medulla was virtually absent towards the end of anagen. The shape of the medulla cross-section was less elliptical than that of the whole hair shaft and was close to circular. There was no significant change in medulla shape through anagen. The form of the medulla was also affected by the hair cycle; approximately, it was continuous for the first 50% of anagen, discontinuous for the next 25% and virtually absent or absent for the final 25%. The maximal size of the medulla, as occurred in early anagen, was markedly associated with the cross-sectional size of the whole hair shaft, both within terminal hairs and between all scalp hairs. The medulla was large in terminal hairs and small or absent in very small hairs. The proportion of the whole hair shaft occupied by the medulla increased with increase in hair size and reached a maximum in terminal hairs, in which the medulla minor axis represented about 30% of the whole hair shaft minor axis. Furthermore, this proportion was constant in the terminal hairs and was not related to whole hair shaft size. Such maximal proportional medullation might represent a defining feature of terminal hairs. Variation in size of the medulla is not the cause of the previously reported cycle-dependent change in cross-sectional size of the whole hair shaft of terminal hairs.

Presentation with multiple cutaneous basal cell carcinomas: association of glutathione S-transferase and cytochrome P450 genotypes with clinical phenotype

We previously reported associations between numbers of basal cell carcinomas (BCCs) and glutathione S-transferase (GSTM1 and GSTT1) and cytochrome P450 (CYP2D6) genotypes. Thus, although GSTM1 AB is protective, GSTM1 null, GSTT1 null, and CYP2D6 EM are associated with increased numbers of lesions. Here, we examine the hypothesis that these genotypes are associated with high-risk subgroups. The subgroup studied comprised 119 patients with more than one previously unidentified BCC at first or later presentations [multiple presentation phenotype (MPP)]. These patients were part of a group of 773 BCC patients that also included 567 patients with one BCC and 87 patients with only one lesion at each presentation [single presentation phenotype (SPP)] but who developed multiple BCCs. The number of tumors in the MPP was significantly greater than that in the SPP groups. In the MPP but not SPP patients, GSTM1 AB, GSTT1 null, and CYP2D6 EM were significantly associated with BCC numbers, suggesting that previously observed associations reflect the influence of these genes only in the MPP cases. There was no evidence that MPP patients had received more UV exposure. We also determined whether the increased numbers of BCC in the MPP cases reflects an association with the truncal tumor phenotype. The values of the rate ratios indicated that the MPP is a marker for the risk of many BCCs, although the combination of MPP and a truncal tumor is a higher-risk phenotype. The data demonstrate the heterogeneity in BCC patients, which reflects differences in genetic factors that determine skin response to UV.

Susceptibility to melanoma: influence of skin type and polymorphism in the melanocyte stimulating hormone receptor gene

Allelic variation at the melanocyte stimulating hormone receptor (MC1R) gene has been linked with sun-sensitive skin types, suggesting it is a susceptibility candidate for melanoma. We determined the frequency of the val92met, asp294his, and asp84glu MC1R alleles in 190 Caucasian controls and 306 melanoma cases and studied their association with skin type and hair color. The percentage of controls with at least one val92met, asp294his, or asp84glu allele was 17.3%, 6.8%, and 3.5%, respectively. Individually, frequencies of the val92met, asp294his, or asp84glu alleles in the controls with skin types 3 and 4 were similar to those with skin types 1 and 2. Trend analysis, however, did identify an association (exact p = 0.048, two-sided test) between skin type and MC1R variants in the group comprising all controls with any one or more of these alleles. There was no association between MC1R alleles and hair color. Allele frequencies were not different in melanoma cases and controls. There were no associations between skin types and the proportion of cases with the asp294his or asp84glu alleles, though the association between skin type and the val92met allele approached significance (exact p = 0.09, two-sided test). Unexpectedly, in the group comprising all cases with one or more variant alleles, the proportion of subjects with variant alleles increased with skin types associated with tanning rather than burning, although trend analysis showed that this association did not quite reach statistical significance (exact p = 0.08, two-sided test). Asp84glu (but not val92met or asp294his) variant alleles were more common in subjects with blonde hair, although the relationship between the asp84glu allele and hair color did not achieve statistical significance (chi(2)3 = 6.16, exact p = 0.10). We interpret the data presented as indicating that polymorphism at MC1R does not appear a major determinant of skin type, at least in terms of these allelic variants. Furthermore, considered alone, these alleles are not susceptibility candidates for malignant melanoma.

Long-term outcome of severe chronic plaque psoriasis following treatment with high-dose topical calcipotriol

We have previously reported the effectiveness of high-dose calcipotriol in extensive psoriasis. We now report the long-term outcome in patients following this treatment. Twenty-eight patients with severe psoriasis were treated as in-patients with high-dose topical calcipotriol for 2 weeks. There was a mean reduction in the psoriasis area and severity index of 65%. Sixty-nine per cent were controlled for 3 months and 42% for 6 months. The relapse rate was comparable with that following Ingram's regimen, the in-patient stay was shorter and the treatment more acceptable. Careful monitoring of calcium homeostasis is mandatory.

Cutaneous vascular infarcts secondary to spontaneous platelet aggregation

We report a 23-year-old woman presenting with multiple cutaneous infarcts who was found to have spontaneous platelet aggregation (SPA). Her skin lesions showed a good response to aspirin therapy and platelet aggregation returned to normal. Subsequently, she was found to have and was treated for pulmonary tuberculosis. The SPA may have been related to this via the formation of immune complexes. Isolated cutaneous infarcts have not previously been described in association with SPA. The role of spontaneous and increased platelet aggregation in skin disorders is discussed.

Platelet fatty acids and peripheral blood lymphocyte subsets in an institutionalized elderly population

The associations between platelet fatty acids and peripheral blood lymphocyte subsets were studied in 78 institutionalized elderly individuals (27 men and 51 women), aged 67 to 100. Platelet fatty acids were assessed by gas chromatography, and peripheral blood lymphocyte subsets were quantitated by immunophenotyping using flow cytometry. It was found that women had a higher number of total T-cells (CD3), T-helper (CD3+4+) cells, and B-cells (CD19). However, no gender differences were observed in the percentages of lymphocyte subsets. In elderly men, after adjusting for age and fatty acid intake, the platelet concentration of omega-3 polyunsaturated fatty acids was positively related to the percentage of CD3 and CD3+4+ bearing lymphocytes (rs = 0.59, P < 0.05; and rs = 0.55, P < 0.05, respectively), and the concentration of total saturated fatty acids was also positively associated with the percentage of B (CD19) cells (rs = 0.50, P < 0.05). However, similar relationships were not observed in elderly women. No significant associations were found between trans fatty acids and any of the lymphocyte subsets in the study population. These findings suggest that fatty acids may be related to immune function. Any effects may be important in the host immune defence, especially in elderly individuals.

The effect of addition of calcipotriol ointment (50 micrograms/g) to acitretin therapy in psoriasis

Our purpose was to find out whether the addition of calcipotriol ointment (50 micrograms/g) to systemic treatment with acitretin produces additional therapeutic effects and thereby an acitretin-sparing effect, and further to investigate the safety and tolerability of this combination. A multicentre, randomized, double-blind placebo-controlled study was designed. Patients were randomized to receive calcipotriol or placebo. All patients were treated with a starting dose of 20 mg acitretin per day and doses were adjusted at 2-weekly intervals with increments of 10 mg per day up to a maximum of 70 mg per day. The dose requirement for acitretin, clinical signs and adverse events were recorded. Seventy-six patients were randomized to treatment with calcipotriol 50 micrograms/g ointment twice daily and 59 patients to treatment with the vehicle only twice daily. Clearance or marked improvement was achieved by 67% of the patients in the calcipotriol group and by 41% of the patients in the placebo group (P = 0.006). Calcipotriol treatment proved to have a statistically significant additional effect to acitretin on the Psoriasis Area and Severity Index, redness, thickness and scaliness as compared with placebo. Clearance or marked improvement was achieved with a statistically significantly lower cumulative dose of acitretin by the patients in the calcipotriol group as compared with the placebo group. The number of patients reporting adverse events was pronounced and largely related to acitretin. No significant differences were observed between the two treatment groups with respect to adverse events. Laboratory assessments were essentially normal. The addition of calcipotriol ointment to acitretin treatment contributes to the efficacy, reduces the cumulative dose of acitretin to reach marked improvement or clearance, and is well-tolerated and safe.

The effects of topical calcipotriol on systemic calcium homeostasis in patients with chronic plaque psoriasis

BACKGROUND

Calcipotriol is an effective treatment of chronic plaque psoriasis. We have previously demonstrated that it has a small effect on systemic calcium homeostasis even at recommended doses.

OBJECTIVE

We attempted to determine the mechanism of the effect of calcipotriol on systemic calcium homeostasis so we could assess the possible consequences of long-term use.

METHODS

Sixteen patients with extensive chronic plaque psoriasis were hospitalized and treated with high-dose topical calcipotriol. Up to 360 gm of calcipotriol (50 micrograms/gm) ointment was applied per week for 2 weeks under controlled conditions.

RESULTS

There was a dose-dependent rise in intestinal absorption of calcium. No effect on bone turnover was demonstrated over this short period. Five patients became hypercalcemic, and there was a dose-dependent rise in serum total adjusted calcium, serum ionized calcium, serum phosphate, urine calcium, and urine phosphate. There was a dose-dependent fall in serum parathyroid hormone and serum 1,25 dihydroxyvitamin D3.

CONCLUSION

Calcipotriol exerts its effects on systemic calcium homeostasis by increasing intestinal absorption of calcium and probably phosphate. This results in suppression of parathyroid hormone and 1,25 dihydroxyvitamin D3.

The effects of UVB plus calcipotriol on systemic calcium homeostasis in patients with chronic plaque psoriasis

We studied the effects of combining topical calcipotriol, used at the maximal licensed dose, and narrow-band short wave ultraviolet light (TL01) on systemic calcium homeostasis in the treatment of chronic plaque psoriasis. Patients were randomized in an open fashion to receive either UVB alone, UVB plus 100 g of calcipotriol (50 micrograms/g) ointment per week or calcipotriol ointment alone (100 g/week). With the exception of a slight increase in serum phosphate in the group receiving combination therapy (from 0.92 to 1.22 mmol/l; P = 0.046), no differences were observed between or within the groups. Psoriasis area and severity scores (PASI) improved to a greater extent in those patients receiving both UVB and calcipotriol (P = 0.045). The combination of UVB and calcipotriol is a safe, effective treatment for chronic plaque psoriasis.

A randomized double-blind comparison of the effects on systemic calcium homeostasis of topical calcitriol (3 micrograms/g) and calcipotriol (50 micrograms/g) in the treatment of chronic plaque psoriasis vulgaris

Calcitriol and calcipotriol are effective treatments for psoriasis, although the two have never been directly compared. We compared the efficacy and toxicity of each agent in 24 patients with moderately extensive chronic plaque psoriasis, who were randomized in double-blind fashion to apply 90 g per week of either calcitriol (3 micrograms/g) ointment or calcipotriol (50 micrograms/g) ointment over an 8-week period. Mean PASI in patients applying calcitriol fell from 13 to 8.8 (p < 0.05) and in patients applying calcipotriol from 14.9 to 4.7 (p < 0.005). The reduction was significantly greater in the calcipotriol-treated group (p < 0.05). There was a small increase in serum ionized calcium in the calcipotriol-treated group (from 1.21 mmol/L to 1.25 mmol/L, p < 0.05) but no effect on calcium homeostasis in the calcitriol group.