Loss-of-Function Variants in the Tumor-Suppressor Gene PTPN14 Confer Increased Cancer Risk

The success of genome-wide association studies (GWAS) in identifying common, low-penetrance variant-cancer associations for the past decade is undisputed. However, discovering additional high-penetrance cancer mutations in unknown cancer predisposing genes requires detection of variant-cancer association of ultra-rare coding variants. Consequently, large-scale next-generation sequence data with associated phenotype information are needed. Here, we used genotype data on 166,281 Icelanders, of which, 49,708 were whole-genome sequenced and 408,595 individuals from the UK Biobank, of which, 41,147 were whole-exome sequenced, to test for association between loss-of-function burden in autosomal genes and basal cell carcinoma (BCC), the most common cancer in Caucasians. A total of 25,205 BCC cases and 683,058 controls were tested. Rare germline loss-of-function variants in PTPN14 conferred substantial risks of BCC (OR, 8.0; P = 1.9 × 10^-12), with a quarter of carriers getting BCC before age 70 and over half in their lifetime. Furthermore, common variants at the PTPN14 locus were associated with BCC, suggesting PTPN14 as a new, high-impact BCC predisposition gene. A follow-up investigation of 24 cancers and three benign tumor types showed that PTPN14 loss-of-function variants are associated with high risk of cervical cancer (OR, 12.7, P = 1.6 × 10^-4) and low age at diagnosis. Our findings, using power-increasing methods with high-quality rare variant genotypes, highlight future prospects for new discoveries on carcinogenesis. SIGNIFICANCE: This study identifies the tumor-suppressor gene PTPN14 as a high-impact BCC predisposition gene and indicates that inactivation of PTPN14 by germline sequence variants may also lead to increased risk of cervical cancer.

Genome-wide meta-analysis identifies eight new susceptibility loci for cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (SCC) is one of the most common cancers in the United States. Previous genome-wide association studies (GWAS) have identified 14 single nucleotide polymorphisms (SNPs) associated with cutaneous SCC. Here, we report the largest cutaneous SCC meta-analysis to date, representing six international cohorts and totaling 19,149 SCC cases and 680,049 controls. We discover eight novel loci associated with SCC, confirm all previously associated loci, and perform fine mapping of causal variants. The novel SNPs occur within skin-specific regulatory elements and implicate loci involved in cancer development, immune regulation, and keratinocyte differentiation in SCC susceptibility.

The authors perform a meta-analysis of cutaneous squamous cell carcinoma, identifying causal variants within skin-specific regulatory elements.

Association of BRCA2 K3326* With Small Cell Lung Cancer and Squamous Cell Cancer of the Skin

Background

Most pathogenic mutations in the BRCA2 gene carry a high risk of hereditary breast and ovarian cancer (HBOC). However, a stop-gain mutation, K3326* (rs11571833), confers risk of lung cancer and cancers of the upper-aero-digestive tract but only a modest risk of breast or ovarian cancer. The Icelandic population provides an opportunity for comprehensive characterization of the cancer risk profiles of K3326* and HBOC mutations because a single mutation, BRCA2 999del5, is responsible for almost all BRCA2-related HBOC in the population.

Methods

Genotype information on 43 641 cancer patients and 370 971 control subjects from Iceland, the Netherlands, and the United States was used to assess the cancer risk profiles of K3326* and BRCA2 999del5. BRCA2 expression was assessed using RNAseq data from blood (n = 2233), as well as 52 tissues reported in the GTEx database.

Results

The cancer risks associated with K3326* are fundamentally different from those associated with 999del5. We report for the first time an association between K3326* and small cell lung cancer (odds ratio [OR] = 2.06, 95% confidence interval [CI] = 1.35 to 3.16) and squamous cell carcinoma of the skin (OR = 1.69, 95% CI = 1.26 to 2.26). Individuals homozygous for K3326* reach old age and have children. Unlike BRCA2 999del5, the K3326* allele does not affect the level of BRCA2 transcripts, and the allele is expressed to the same extent as the wild-type allele.

Conclusions

K3326* associates primarily with cancers that have strong environmental genotoxic risk factors. Expression of the K3326* allele suggests that a variant protein may be made that retains the DNA repair capabilities important to hormone-responsive tissues but may be less efficient in responding to genotoxic stress.

HLA-Cw6 homozygosity in plaque psoriasis is associated with streptococcal throat infections and pronounced improvement after tonsillectomy: A prospective case series

BACKGROUND

Carriage of the HLA-Cw*0602 allele is associated with a particular set of clinical features and treatment responses in psoriasis. Tonsillectomy can improve psoriasis.

OBJECTIVES

We sought to evaluate whether HLA-Cw*0602 predicts a favorable outcome after tonsillectomy of patients with psoriasis.

METHODS

This prospective case series followed up 28 tonsillectomized patients with plaque psoriasis for 24 months. The Psoriasis Area and Severity Index, Psoriasis Disability Index, and Psoriasis Life Stress Inventory were used for assessment. Tonsils were swabbed for bacteria and patients genotyped for HLA-Cw*0602.

RESULTS

After tonsillectomy, HLA-Cw*0602 homozygotes showed significantly more improvement, compared with heterozygous and HLA-Cw*0602-negative patients. Thus, Psoriasis Area and Severity Index score was reduced by 82% in the homozygous patients compared with 42% and 31%, respectively (P < .001), Psoriasis Disability Index score improved by 87% compared with 38% and 41%, respectively (P < .001), and Psoriasis Life Stress Inventory score was 82% reduced compared with 60% and 54%, respectively (P < .001). The homozygotes more often had psoriasis onset associated with a throat infection (P = .007) and an increased frequency of streptococcal throat infections per lifetime (P = .038).

LIMITATIONS

Few patients were included and some data were retrospective.

CONCLUSIONS

Homozygous HLA-Cw*0602 carriage in plaque psoriasis may predict a favorable outcome after tonsillectomy.

New basal cell carcinoma susceptibility loci

In an ongoing screen for DNA sequence variants that confer risk of cutaneous basal cell carcinoma (BCC), we conduct a genome-wide association study (GWAS) of 24,988,228 SNPs and small indels detected through whole-genome sequencing of 2,636 Icelanders and imputed into 4,572 BCC patients and 266,358 controls. Here we show the discovery of four new BCC susceptibility loci: 2p24 MYCN (rs57244888[C], OR=0.76, P=4.7 × 10⁻¹²), 2q33 CASP8-ALS2CR12 (rs13014235[C], OR=1.15, P=1.5 × 10⁻⁹), 8q21 ZFHX4 (rs28727938[G], OR=0.70, P=3.5 × 10⁻¹²) and 10p14 GATA3 (rs73635312[A], OR=0.74, P=2.4 × 10⁻¹⁶). Fine mapping reveals that two variants correlated with rs73635312[A] occur in conserved binding sites for the GATA3 transcription factor. In addition, expression microarrays and RNA-seq show that rs13014235[C] and a related SNP rs700635[C] are associated with expression of CASP8 splice variants in which sequences from intron 8 are retained.

Basal cell carcinoma is a common cancer among people of European ancestry, with associated high economic costs to monitor and treat. Here Stacey et al. conduct a genome-wide association study on Icelandic and other European populations, identifying four novel loci associated with cancer susceptibility.

Germline sequence variants in TGM3 and RGS22 confer risk of basal cell carcinoma

To search for new sequence variants that confer risk of cutaneous basal cell carcinoma (BCC), we conducted a genome-wide association study of 38.5 million single nucleotide polymorphisms (SNPs) and small indels identified through whole-genome sequencing of 2230 Icelanders. We imputed genotypes for 4208 BCC patients and 109 408 controls using Illumina SNP chip typing data, carried out association tests and replicated the findings in independent population samples. We found new BCC susceptibility loci at TGM3 (rs214782[G], P = 5.5 × 10⁻¹⁷, OR = 1.29) and RGS22 (rs7006527[C], P = 8.7 × 10⁻¹³, OR = 0.77). TGM3 encodes transglutaminase type 3, which plays a key role in production of the cornified envelope during epidermal differentiation.

A melanoma epidemic in Iceland: possible influence of sunbed use

Since 1980, sunbed use and travel abroad have dramatically increased in Iceland (64°-66°N). The authors assessed temporal trends in melanoma incidence by body site in Iceland in relation to sunbed use and travel abroad. Using joinpoint analysis, they calculated estimated annual percent changes (EAPCs) and identified the years during which statistically significant changes in EAPC occurred. Between 1954 and 2006, the largest increase in incidence in men was observed on the trunk (EAPC = 4.6%, 95% confidence interval: 3.2, 6.0). In women, the slow increase in trunk melanoma incidence before 1995 was followed by a significantly sharper increase in incidence, mainly among women aged less than 50 years, resembling an epidemic incidence curve (1995-2002: EAPC = 20.4%, 95% confidence interval: 9.3, 32.8). In 2002, the melanoma incidence on the trunk was higher than the incidence on the lower limbs for women. Sunbed use in Iceland expanded rapidly after 1985, mainly among young women, and in 2000, it was approximately 2 and 3 times the levels recorded in Sweden and in the United Kingdom, respectively. Travels abroad were more prevalent among older Icelanders. The high prevalence of sunbed use probably contributed to the sharp increase in the incidence of melanoma in Iceland.

Sequence variants at the TERT-CLPTM1L locus associate with many cancer types

The common sequence variants that have recently been associated with cancer risk are particular to a single cancer type or at most two. Following up on our genome-wide scan of basal cell carcinoma, we found that rs401681[C] on chromosome 5p15.33 satisfied our threshold for genome-wide significance (OR = 1.25, P = 3.7 x 10(-12)). We tested rs401681 for association with 16 additional cancer types in over 30,000 cancer cases and 45,000 controls and found association with lung cancer (OR = 1.15, P = 7.2 x 10(-8)) and urinary bladder, prostate and cervix cancer (ORs = 1.07-1.31, all P < 4 x 10(-4)). However, rs401681[C] seems to confer protection against cutaneous melanoma (OR = 0.88, P = 8.0 x 10(-4)). Notably, most of these cancer types have a strong environmental component to their risk. Investigation of the region led us to rs2736098[A], which showed stronger association with some cancer types. However, neither variant could fully account for the association of the other. rs2736098 corresponds to A305A in the telomerase reverse transcriptase (TERT) protein and rs401681 is in an intron of the CLPTM1L gene.

Two newly identified genetic determinants of pigmentation in Europeans

We present results from a genome-wide association study for variants associated with human pigmentation characteristics among 5,130 Icelanders, with follow-up analyses in 2,116 Icelanders and 1,214 Dutch individuals. Two coding variants in TPCN2 are associated with hair color, and a variant at the ASIP locus shows strong association with skin sensitivity to sun, freckling and red hair, phenotypic characteristics similar to those affected by well-known mutations in MC1R.

CDKN2A mutations and melanoma risk in the Icelandic population

BACKGROUND

Germline CDKN2A mutations have been observed in 20-40% of high risk, melanoma prone families; however, little is known about their prevalence in population based series of melanoma cases and controls.

METHODS

We resequenced the CDKN2A gene, including the p14ARF variant and promoter regions, in approximately 703 registry ascertained melanoma cases and 691 population based controls from Iceland, a country in which the incidence of melanoma has increased rapidly.

RESULTS

We identified a novel germline variant, G89D, that was strongly associated with increased melanoma risk and appeared to be an Icelandic founder mutation. The G89D variant was present in about 2% of Icelandic invasive cutaneous malignant melanoma cases. Relatives of affected G89D carriers were at significantly increased risk of melanoma, head and neck cancers, and pancreatic carcinoma compared to relatives of other melanoma patients. Nineteen other germline variants were identified, but none conferred an unequivocal risk of melanoma.

CONCLUSIONS

This population based study of Icelandic melanoma cases and controls showed a frequency of disease related CDKN2A mutant alleles ranging from 0.7% to 1.0%, thus expanding our knowledge about the frequency of CDKN2A mutations in different populations. In contrast to North America and Australia where a broad spectrum of mutations was observed at a similar frequency, in Iceland, functional CDKN2A mutations consist of only one or two different variants. Additional genetic and/or environmental factors are likely critical for explaining the high incidence rates for melanoma in Iceland. This study adds to the geographic regions for which population based estimates of CDKN2A mutation frequencies are available.

Evaluation of a rapid Gram stain interpretation method for diagnosis of bacterial vaginosis

A simple Gram stain evaluation for the diagnosis of bacterial vaginosis was assessed in comparison to Nugent's method. The sensitivity (90%), specificity (94%), positive and negative predictive values (90% and 94%), and good interobserver agreement obtained indicate that the test method can be performed reliably in the routine clinical microbiology laboratory.

Risk factors for malignant melanoma in an Icelandic population sample

OBJECTIVES

To describe the constitutional risk factors for malignant melanoma and exposure to sunlight in a population sample in Iceland.

METHODS

Information on various risk factors for malignant melanoma was collected through mailed questionnaires sent to a random sample of the Icelandic population. The information collected was the first phase of a prospective study on malignant melanoma among aircrew members as compared to a population sample.

RESULTS

The overall participation rate was about 50%. Seven percent of women and six percent of men had red hair color. Blue or green eye color was reported among 89% of women and 87% of men. Sixteen percent of women aged 20 to 39 had used sun beds more than 100 times during their lifetime, while the corresponding figure was 12% for men of the same age. Younger age groups had more sunny vacations than the older age groups. The frequency of sunburn differed in the groups with reported different skin types according to Fitzpatrick classification.

CONCLUSION

The high prevalence of sun bed usage among young women is concurrent with the increased incidence of malignant melanoma among young women registered in the nationwide cancer registry. Young people have more often used sun beds and taken sunny vacation than the older, indicating a changed behavior in the population.

Combination therapy for onychomycosis

Combination therapy is one way of improving the cure rate of onychomycosis. The LION Study examined the efficacies of terbinafine and itraconazole. The Icelandic cohort of the study reported that after 5 years only 46% of the terbinafine-treated patients and 13% of the itraconazole-treated patients were still disease-free, suggesting that relapses and reinfections were common in the long term treatment of onychomycosis with monotherapy. Combination therapy is a well-established principle in mycology; the current strategy involves the combination of oral and topical antifungal treatments. A number of specific drug combinations have proved to be useful in the treatment of onychomycosis: tioconazole and griseofulvin, amorolfine and griseofulvin, amorolfine and terbinafine, and amorolfine and itraconazole. However, comparison of the combination trials can be difficult because of the short duration of some of the studies and variation in global cure rates. Although it is necessary to consider these factors it is clear that combination therapy offers advantages when compared with monotherapy. Combination therapy can be administered sequentially or in parallel. Parallel therapy is recommended for patients who are likely to fail therapy (e.g. patients with diabetes), whereas sequential therapy is recommended for patients who show a poor response to initial treatment.

Nordic Occupational Skin Questionnaire (NOSQ-2002): a new tool for surveying occupational skin diseases and exposure

Occupational skin diseases are among the most frequent work-related diseases in industrialized countries. Good occupational skin disease statistics exist in few countries. Questionnaire studies are needed to get more data on the epidemiology of occupational skin diseases. The Nordic Occupational Skin Questionnaire Group has developed a new questionnaire tool - Nordic Occupational Skin Questionnaire (NOSQ-2002) - for surveys on work-related skin disease and exposures to environmental factors. The 2 NOSQ-2002 questionnaires have been compiled by using existing questionnaires and experience. NOSQ-2002/SHORT is a ready-to-use 4-page questionnaire for screening and monitoring occupational skin diseases, e.g. in a population or workplace. All the questions in the short questionnaire (NOSQ-2002/SHORT) are included in the long version, NOSQ-2002/LONG, which contains a pool of questions to be chosen according to research needs and tailored to specific populations. The NOSQ-2002 report includes, in addition to the questionnaires, a comprehensive manual for researchers on planning and conducting a questionnaire survey on hand eczema and relevant exposures. NOSQ-2002 questionnaires have been compiled in English and translated into Danish, Swedish, Finnish and Icelandic. The use of NOSQ-2002 will benefit research on occupational skin diseases by providing more standardized data, which can be compared between studies and countries.

Comparison of Roche Cobas Amplicor and Abbott LCx for the rapid detection of Chlamydia trachomatis in specimens from high-risk patients

OBJECTIVE

To evaluate two automated amplification systems for the detection of Chlamydia trachomatis in urogenital specimens, the Cobas Amplicor (Roche Diagnostic Systems, Branchburg, NJ) and the LCx (Abbott Laboratories, Abbott Park, IL).

STUDY DESIGN

The two systems were compared testing specimens from 302 high-risk patients, including 98 female cervical swab specimens and 204 male urine specimens. The patients attended the state STD clinic in Reykjavik, Iceland, either because of symptoms or as a result of contract tracing.

RESULTS

The prevalence of C. trachomatis infection was 15.3% in women and 13.2% in men. For the male urine specimens, the sensitivity and specificity were 100% and 99.4% for the Cobas Amplicor and 74.1% and 100% for the LCx. In the cervical swabs, both systems detected all 15 true-positive specimens. The internal control used with the Cobas Amplicor detected inhibition in 2% of the male urine and 20% female cervical swabs, respectively.

CONCLUSION

The Cobas Amplicor demonstrated slightly better sensitivity than LCx in male urine specimens. Both systems offer the benefits of automation for routine diagnostic testing.

[Cutaneous leishmaniasis. A case report.]

Cutaneous leishmaniasis is a common infection in South America and the Middle East. A 20 year Icelander was infected with leishmaniasis while travelling in South America. Treatment with the antimonial sodium stibogluconate was successful. With increased travelling to tropical and subtropical countries a rising incidence of tropical infectious diseases can be expected in Iceland.

Effect of various marine lipids on transdermal drug delivery--in vitro evaluation

The effects of several marine lipids on the penetration of hydrocortisone and nitroglycerin through excised hairless mouse skin have been studied. Fatty acid extracts obtained by hydrolysis of Portuguese dog-fish-liver-oil or by hydrolysis of cod-liver-oil were shown to be effective skin penetration enhancers. Phospholipid obtained from squid was also shown to be effective enhancer. However, the enhancing effect of the marine products could generally be associated with their content of free unsaturated fatty acids. The fatty acid extract obtained from cod-liver-oil caused insignificant skin irritation when incorporated into an ointment base and applied to human skin.

Unsaturated glycerol monoethers as novel skin penetration enhancers

A mixture of glycerol monoethers was extracted from the liver oil of deep sea shark (Centroporus squamosus). It consisted mainly of monoethers of glycerol and linear monounsaturated octadecanol, and glycerol and linear monounsaturated hexadecanol. Only about 11% of the extract consisted of glycerol monoethers derived from linear saturated fatty alcohols. The glycerol monoether extract was somewhat less effective as skin penetration enhancer than oleic acid and other potent fatty acid penetration enhancers, but it was still a very effective enhancer in the hairless mouse skin model used in this study.

Reduced prevalence of cervical Chlamydia infection among women requesting termination

BACKGROUND

The prevalence and pattern of Chlamydia trachomatis infection among women requesting induced abortion in the three year period 1992-95 was evaluated and compared to the results of a previous study in 1982-84, where the prevalence of chlamydial infection had been 13.5%.

METHODS

A total of 1995 women requested termination, 1855 (93%) of whom were tested for Chlamydia and were included in the study. Two types of tests for chlamydial infection, ELISA and PCR, were used in two consecutive periods. In addition cultures for gonorrhea were done in each case. Information on age, marital status, parity, gestational age and the results of chlamydia and gonorrhea tests of the women and sexual partners were recorded.

RESULTS

Chlamydia trachomatis positive women were 149 (8.0%), a significant reduction from the previous 1982-84 study (p<0.001). Women with positive tests were significantly younger (80% < or = 25 years of age; p<0.001) and more frequently single (86.6%; p<0.001), than those with negative tests, as in the previous period. Of the partners, 80.4% were contacted, and 52.1% presented for investigation. Of those tested 42.1% were Chlamydia positive. Four women (0.2%) had Neisseria gonorrhea but none of the partners.

CONCLUSIONS

The prevalence of Chlamydia trachomatis is receding among women coming for termination of pregnancy. As treatment before or at operation has repeatedly been shown to be of benefit and since the prevalence is still considerable, continued screening of these women is justified.

Oral terbinafine in toenail dermatophytosis. A double-blind, placebo-controlled multicenter study with 12 months' follow-up

The treatment of onychomycosis has previously often been protracted and unsuccessful. Terbinafine has been shown to be effective in short-term regimens. In this double-blind, placebo-controlled study, 148 patients with toenail dermatophytosis were randomized to treatment with either 250 mg terbinafine daily or placebo for 3 months. An additional treatment was given for 3 months to patients whose infection had not responded. The patients were followed clinically and mycologically through 12 months. After 3 months 82% of the terbinafine-treated group, versus 5% of the placebo group, showed significant improvement, i.e. negative culture and growth of unaffected nail more than 2 mm (p = < 0.0001). After 12 months clinical and mycological cure was seen in 40% of the patients treated with terbinafine for 3 or 6 months, while 67-81% were clinically cured, but with positive microscopy. Side-effects occurred in 13.5% of the terbinafine group, versus 5.4% of the placebo group, and were mild. 250 mg terbinafine daily for 3 months was significantly more effective than placebo. The efficacy did not appear to improve with additional treatment for 3 months.

[Dermatitis in cats and humans caused by Cheyletiella mites reported in Iceland.]

Cheyletiella mites (Acarina) are ectoparasites that infest cats, dogs and rabbits in many countries of the world. Upon contact with infested animals the mites may temporarily produce grouped, erythematous macules on the skin of humans which rapidly develop a central, vesicular papule. These signs are most often found on the arms and the trunk. Recently these typical signs were observed on the skin of the members of two different Icelandic families which both kept a Persian cat. An examination for ectoparasites on the cats revealed that both were infested by Cheyletiellaparasitovorax. It is unknown how and when the parasite was transmitted to Iceland.

Psoriasis treatment: bathing in a thermal lagoon combined with UVB, versus UVB treatment only

We have compared bathing in a thermal lagoon in Iceland, combined with UVB treatment, to UVB treatment only in an open comparative study. Twenty-three psoriasis patients bathed 3 times daily and were treated with UVB 5 times a week for 4 weeks. The control group was only treated with UVB 5 times a week for 4 weeks. Psoriasis Area and Severity Index (PSAI) was used to estimate the severity of the disease. The mean PASI score in the bathing group decreased from 20.8 to 2.8 (p < 0.01). In the control UVB group, the PASI score decreased from 16. 7 to 6.9. The percentage difference between the groups was significant after 1, 2, 2 and 4 weeks. Bathing in the lagoon combined with UVB was found to be a very effective treatment and better than UVB treatment in our control group.

Diagnosis of Chlamydia trachomatis infection in high-risk females with PCR on first void urine

Recently the polymerase chain reaction (PCR) has been shown to be more sensitive than older methods in detecting Chlamydia trachomatis, when performed on endocervical swabs. A total of 203 high-risk females were enrolled in a comparative study of 3 methods for diagnosing C. trachomatis infections: McCoy cell culture and Amplicor PCR on endocervical swabs, and urine. Thirty-four had positive cultures, 38 positive PCR from cervix and 37 had positive PCR on urine specimens. When discrepancy occurred, the leftover Amplicor specimen was retested by Roche with Amplicor and a primer for the major outer membrane protein (MOMP) gene. In all three tests, 32 were positive. The sensitivity of culture was 87%, 92% in cervical PCR and 95% in urinary PCR. The specificity was 100% in both culture and urinary PCR but 98% in cervical PCR. Amplicor PCR performed on female urine is at least as sensitive and specific as cell culture.

[Prevalence of genital chlamydia trachomatis infections in college students.]

Sexually transmitted Chlamydia infection is the most common venereal disease in Iceland. Although considerable information is available on the epidemiology of these infections, the true prevalence of C. trachomatis infections in Iceland is unknown because all the studies have been conducted on selected populations. The purpose of the present study was twofold: To investigate the prevalence of Chlamydia infection in an unselected group of people in the age group at high risk, and to investigate the usefulness of collecting urine samples from college students as a screening method for Chlamydia. All students, aged 18-21, in the senior classes in a college in Reykjavik were requested to submit a first void urine (FVU) specimen taken in the morning and asked to fill out a short questionnaire. The urine samples were tested with a polymerase chain reaction assay, the Amplicor(R) PCR. One hundred eighty three students received urine collection kits. One hundred sixty (87.4%) delivered specimens. Seventy three males and 110 females received the containers. Sixty males (82%) and 100 (91%) females returned the samples. Three samples turned out to be positive (2%), all of them from females. For those who were sexually active (one or more partners for the last six months) the prevalence was 2.6% (117/160).

IN CONCLUSION

The prevalence of asymptomatic Chlamydia infection in college students in this school was low, probably too low for screening to be cost effective. The procedure was not satisfactory because of the low percentage that enquired about their tests. It is therefore unsuitable in a screening program.

[Clinical evaluation of two immunoassay methods for the rapid detection of chlamydia trachomatis: antigen in endocervical specimens from high risk female patients.]

Two rapid immunoassay methods, QuickVue-Chlamydia (Quidel Corp., San Diego California) and Kodak Surecell (Kodak Corp. Rochester, N.Y.) were evaluated for the detection of Chlamydia trachomatis antigen in endocervical swabs from high risk females attending a sexually transmitted disease clinic. The results were compared to McCoy cell culture and a polymerase chain reaction assay (Amplicor(R)-PCR, Roche Molecular Systems). Of the 240 females enrolled in the study 45 were considered infected (18.8%). Sensitivity, specificity, predictive value of a positive (PVP) and predictive value of a negative (PVN) of the QuickVue-Chlamydia assay were 96%, 99%, 96% and 99% respectively. Sensitivity, specificity, PVP and PVN of the Surecell assay were 96%, 100%, 100% and 99% respectively. The performance of the two immunoassay methods was similar, the sensitivity was the same and the specificity of the Kodak Surecell was slightly better than that of the QuickVue. On the other hand, the QuickWVL-Chlamydia assay was considerably simpler to perform (fewer steps) than the Kodak Surecell assay and took significantly less of technologists time.

[Diagnostic efforts for the detection of chlamydia trachomatis infections in Iceland 1982-1994.]

The results of diagnostic testing for the detection of Chlamydial infections in Iceland during the years 1982 to 1994 were reviewed. During those 13 years 123,461 laboratory tests were performed in 101,574 examinations. These examinations were positive in 14,462 instances. The first diagnostic test to be introduced was cell culture in 1982. From then on the number of examinations and the number of positive examinations increased steadily until 1988, when positive examinations reached a peak at approximately 570 cases per 100,000 inhabitants. In 1990 a sharp decline in both the total number of examinations and positive results was observed. The percentage of positive examinations declined during the study period. In 1991 and 1992 the number of examinations, the number of positive examinations and the percentage of positive examinations increased but the number of positive tests declined again in 1993. In 1994 the polymerase chain reaction assay (PCR) replaced the much less sensitive Chlamydiazyme(R) assay and the number of positive examinations rose again although the number of tests declined. The dramatic reduction in prevalence experienced in Sweden does not seem to have taken place in Iceland. In Sweden a substantial effort was made to screen asymptomatic populations. In Iceland the screening of asymptomatic patients increased from the beginning of the study period until 1988 but declined thereafter. Screening of asymptomatic populations as well as contact tracing may be important for bringing about a significant reduction of the prevalence of sexually transmitted infections caused by Chlamydia trachomatis.

[Lower genital tract infection with chlamydia trachomatis in women requesting induced abortion.]

Postoperative pelvic infection is a serious complication of induced abortion, and may occur in 2-6% of cases. A study of the prevalence and distribution by age and marital status of cervical Chlamydia infection in 1991-93 in women seeking termination of pregnancy is in progress. The data for 1993 are presented and compared to results from a previous study. There were 686 women requesting termination of pregnancy in 1993. Of those 636 had induced abortion by suction evacuation, 11 aborted spontaneously, three were not pregnant, two were refused termination of pregnancy and 34 women withdrew their request. Of those who had the operation, 633 (92.3%) had samples taken and 48 were Chlamydia trachomatis positive (7.6%). The reduction from the previous study was significant where 13.5% of the women were Chlamydia positive. The Chlamydia positive women were also younger and more often single than those who were negative. It has been shown that if Chlamydia positive women are treated the incidence of later endometritis and salpingitis is not higher than among those that are negative. This emphasizes the importance of screening and treating Chlamydia positive women requesting termination of pregnancy.

[Diagnosis of chlamydia trachomatis infections in women: urinary PCR compared to cervical culture and PCR on cervical swabs in high risk females.]

Diagnosis of Chlamydia trachomatis infections in women has traditionally depended on cell culture or enzyme linked immunoassay. Recently Polymerase Chain Reaction (PCR) has been shown to be more sensitive than these methods when performed on endocervical swabs. A total of 203 high risk females were enrolled in a comparative study of three methods for diagnosing C. trachomatis infections: McCoy cell culture and Amplicor(R) PCR on endocervical swabs and urine. Thirty four had positive cultures, 38 positive PCR from cervix and 37 had positive PCR on urine specimens. When discrepancy occurred, the leftover Amplicor(R) specimen was retested by Roche with Amplicor(R) and a primer for the Major Outer Membrane Protein (MOMP) gene. None was false positive in cell culture or in urinary PCR but two were false positive in cervical PCR. In all three tests, 32 were positive. The sensitivity of culture was 87%, 92% in cervical PCR and 95% in urinary PCR. The specificity was 100% in both culture and urinary PCR but 98% in cervical PCR. The results show that Amplicor(R) PCR performed on female urine is more sensitive and as specific as cell culture.

[Clinical evaluation of a rapid polymerase chain reaction (PCR) assay: for the detection of chlamydia trachomatis in specimens from high risk patients.]

A Rapid Polymerase Chain Reaction Assay (Ampli-cor(R)-PCR) was evaluated for the detection of Chlamydia trachomatis in specimens from 179 high risk patients. The results were compared to McCoy cell culture and specimens were retested with Amplicor(R) and primers for the Major Outer Membrane Protein (MOMP) gene when discrepancy occurred. Of 88 females enrolled in the study, 30 were infected (34%). Sensitivity, selectivity, predictive value of a positive (PVP) and a negative (PVN) on endocervical specimens were 97%, 96.5%, 96.5% and 98% respectively. Of 91 male urine specimens, 33 (36%) came from infected patients. The sensitivity and specificity of the Amplicor(R) assay was 94% and 74% respectively for male urine specimens and the PVP and PVN were 72% and 96% respectively. The sensitivity was low on the original run on urethral specimens but the majority of false negative specimens became positive when retested. Amplicor(R) performed on urine samples was the most sensitive test for detecting Chlamydial infections in males.

Clinical evaluation of an automated enzyme-linked fluorescent assay for the detection of chlamydial antigen in specimens from high-risk patients

A fully automated enzyme-linked fluorescent assay (ELFA) on the Vitek Immunodiagnostic Assay System (VIDAS CHL) was evaluated for the detection of chlamydial antigen in specimens from symptomatic and asymptomatic high-risk patients. The results were compared with those from McCoy cell culture and Chlamydiazyme with a blocking assay. False-positive VIDAS specimens were centrifuged and the pellet stained with direct fluorescent antibody (DFA). Of the 158 urine specimens, 52 (33%) were infected by Chlamydia trachomatis. The sensitivity and specificity of the VIDAS when compared with cell culture, DFA, and Chlamydiazyme were 75% and 96%, respectively, for urine specimens while the predictive value of a positive (PVP) and a negative (PVN) were 91% and 88%, respectively. Of the 245 urethral swabs, 75 (31%) were considered positive. The sensitivity and specificity were 71% and 92%, respectively, and the PVP and PVN were 80% and 87%, respectively. The sensitivity and specificity on the 108 cervical swabs, 22 of which were positive, were 95% and 95%, respectively, and PVP and PVN were 88% and 99%, respectively. Compared with Chlamydiazyme, the VIDAS was more sensitive on specimens from female patients and urine specimens, but less sensitive on urethral specimens from male patients.

Single dose azithromycin treatment of gonorrhea and infections caused by C. trachomatis and U. urealyticum in men

BACKGROUND AND OBJECTIVES

Single dose regimens have advantages in the treatment of STD. Azithromycin has unique pharmacokinetics that may make single dose regimens feasible. Treatment with a single 1 g dose of azithromycin was compared to 100 mg doxycycline twice daily for seven days.

STUDY DESIGN

This was a randomized third-party blinded study on 183 male patients, 176 of whom could be evaluated for efficacy.

RESULTS

Chlamydia trachomatis was cultured from 148 patients, 79 receiving azithromycin and 69 receiving doxycycline. Six patients receiving azithromycin had positive cultures on follow-up, four were known to have had sexual intercourse with infected partners. Fifty-one patients had gonorrhea; 28 were treated with azithromycin and 23 with doxycycline. Neisseria gonorrhoeae was eradicated from all patients except one receiving azithromycin. He denied sexual exposure during follow-up. Sixty patients were infected with Ureaplasma urealyticum, 35 were treated with azithromycin and 25 with doxycycline. Five patients in each group had positive cultures on follow up. Three patients receiving azithromycin and two receiving doxycycline were known to have had sexual exposure during follow-up.

CONCLUSION

A single dose of azithromycin showed similar effectiveness as a 7-day regimen of doxycycline.

Azithromycin in the treatment of sexually transmitted disease

One hundred and eighty-two patients were enrolled in a randomized third-party blinded study to assess the efficacy and safety of azithromycin in the treatment of sexually transmitted diseases. Three regimens of azithromycin, including a single oral dose, were compared with a standard treatment with doxycycline. The patients were followed for four weeks. Efficacy was evaluated in 168 patients (113 azithromycin, 55 doxycycline). Fourteen patients had negative cultures or did not come for all follow-up visits. Of the 168, 138 were infected with Chlamydia trachomatis, 43 with Neisseria gonorrhoeae, and 45 with Ureaplasma urealyticum. Ninety-six per cent of patients with chlamydial infections and 92% of those with gonorrhoea were cured with azithromycin. Two patients infected with N. gonorrhoeae, four with C. trachomatis and six with U. urealyticum had positive cultures on follow-up visits after receiving azithromycin. Of these 11 patients with positive cultures on follow-up visits, seven (five with U. urealyticum and two with C. trachomatis) violated the protocol by having intercourse with infected individuals during the study. Azithromycin was very well tolerated; one patient complained of mild abdominal pain shortly after receiving the drug, seven patients complained of mild nausea and two patients had mild diarrhoea.

Treatment of chronic urticaria with PUVA or UVA plus placebo: a double-blind study

Chronic urticaria is a disease for which the available range of treatment modalities is limited. Ultraviolet radiation has recently been shown to affect histamine release from mast cells. We therefore studied the effects of PUVA and UVA on chronic urticaria. Nineteen patients took part in the study, which was designed as a randomized double-blind study. Eleven patients received PUVA, and 8 received UVA plus a placebo. In the PUVA group, 7 patients showed improvement, 3 noticed no change, and 1 became worse. In the group that received UVA plus placebo, 5 patients experienced an improvement, whereas the other 3 showed no change. The differences between the groups were not statistically significant. However, the probability of achieving this degree of improvement in both groups just by chance is less than 1%. Consequently, the improvement noted could have been due to either UVA alone or a placebo effect. It is concluded that PUVA is not better than UVA in the treatment of chronic urticaria.

The bone marrow in urticaria pigmentosa and systemic mastocytosis. Cell composition and mast cell density in relation to urinary excretion of tele-methylimidazoleacetic acid

The bone marrow sections from five normal subjects and 18 patients with mastocytosis were examined to establish criteria to distinguish urticaria pigmentosa from systemic mastocytosis. Nine patients had increased numbers of mast cells in bone marrow sections stained with a long toluidine blue staining technique specific for mast cells, whereas five patients exhibited increased numbers of mast cells on May-Grünwald-Giemsa-stained smears of bone marrow. A positive correlation between the number of mast cells in sections of the bone marrow and the urinary excretion of the main histamine metabolite tele-methylimidazoleacetic acid was found. In ten of the examined bone marrow specimens, focal lesions containing mast cells, lymphocytes, and eosinophils appeared. The presence of these focal lesions together with either an increased number of mast cells in bone marrow sections and/or increased urinary excretion of telemethylimidazoleacetic acid is considered diagnostic of systemic mastocytosis. No patient exhibited myeloproliferative condition or other major hematologic abnormality.

Treatment of two mastocytosis patients with a histidine decarboxylase inhibitor

Alpha-fluoromethylhistidine, alpha-FMH (L-641.575, Merck, Sharp and Dohme), a specific irreversible inhibitor of the mammalian histidine decarboxylase, was investigated for its effect on possible histamine symptoms in mastocytosis. Two patients were treated for 28 and 22 weeks respectively. The first patient had systemic mastocytosis and a severe malabsorption causing weight loss, excessive fecal fat losses and electrolyte disturbances, the main symptom being frequent diarrhoea. The second patient had mainly skin manifestations diagnosed as urticaria pigmentosa and the main symptom was pruritus. There were no side effects of the drug. The first patient produced formed stools after one week of treatment, concomitant with a decrease in plasma histamine and in urinary excretion of the main histamine metabolite tele-methylimidazoleacetic acid (MeImAA). In the second patient definite benefit of the treatment was observed after two months. However, changes in histamine parameters occurred earlier. Plasma histamine and urinary MeImAA were reduced after one week and in two or three weeks reached a steady-state level of about 25% of pretreatment values. The results indicate an effective inhibition of histamine synthesis in both patients but only the diarrhoea seemed to be causally related to the change in histamine metabolism.

Suppression of T lymphocyte mitogen response in patients with mastocytosis

Immunological functions were studied in 22 patients with mastocytosis. Lymphocyte stimulation with concanavalin A (Con A) and phytohemagglutinin showed that the patients responded with lower mitogenic activity than healthy controls. Furthermore, the lymphocytes of patients with the most extensive mast cell disease had a significantly lower Con A mitogen response than the lymphocytes of the rest of the patients. The effect of histamine and its specific metabolites, tele-methylhistamine and tele-methylimidazoleacetic acid (MeImAA), on the Con A lymphocyte mitogen response was also studied in healthy controls. Histamine had a clear suppressive effect, while the metabolite tele-methylhistamine caused only slight inhibition and MeImAA apparently had no effect. The total T cell, suppressor and helper cell numbers, measured with monoclonal antibodies, and the amount of immunoglobulins in serum were found to be normal.

HLA and lymphocyte histamine sensitivity in mastocytosis

HLA-ABC and DR typing was performed on 50 patients with mastocytosis. Lymphocyte stimulation with concanavalin A has earlier been performed in 22 of these patients. No phenotypic aberrations were detected in the patient group. 8 patients had the HLA-B12 phenotype. Lymphocytes from the HLA-B12 phenotype stimulated with a lymphocyte mitogen have earlier been shown to react with decreased inhibitory effect to histamine. 2 patients in this study had the HLA-B12 phenotype and systemic mastocytosis with high histamine turnover, but these patients reacted with a low mitogen response of the lymphocytes.

Studies on histamine metabolism in mastocytosis

The urinary excretion of histamine and its main metabolite, 1-methyl-4-imidazoleacetic acid (MeImAA), was determined in 30 adult patients with the clinical diagnosis of urticaria pigmentosa (UP). Clinical and laboratory investigations including skin histology, bone marrow examination, and scintigraphy of the skeleton, liver, and spleen revealed systemic manifestations in 14 cases. Among the 16 cases with dermal proliferation of mast cells only 3 cases classified as telangiectasia macularis eruptiva perstans (TMEP). All patients with systemic mastocytosis and UP excreted increased amounts of MeImAA in the urine while normal amounts were found in 2 of the patients with TMEP. A significant correlation existed between MeImAA excretion and the extent of mast cell infiltration in skin and internal organs. No such correlation was found for urinary histamine. Urinary MeImAA but not histamine is therefore considered a useful indicator of systemic involvement by reflecting the size of the mast cell histamine pool. The main symptom of the patients was pruritus, which was moderate to severe in 17 and mild or absent in 13 cases. Gastrointestinal symptoms were present in 14 patients. However, there was no obvious correlation between the excretion of MeImAA and any of the symptoms recorded. Neither was the severity of pruritus correlated to the histamine content of the skin, which was measured in both lesional and unaffected skin in 23 of the patients. Thus, symptoms possibly caused by histamine in mastocytosis patients are not directly related to urinary histamine metabolite excretion or tissue histamine content.

Effect of antihistamins (H1 and H2), cortisone and beta-adrenergic stimulator on murine contact sensitivity and histamine metabolism

A study on the influence of histamine receptor blockade, beta-adrenergic stimulation and cortisone on murine cutaneous inflammation and histamine metabolism has been performed. Cortisone was found to reduce the inflammation and urinary histamine excretion while histamine receptor blockade and beta-adrenergic stimulation did not influence the reaction. A good correlation existed between inflammation and urinary histamine excretion in all experiments. Contact sensitivity in the mouse was not found to be transferable with serum indicating that humoral antibodies play no essential role in this reaction in the mouse. On the basis of these results it is suggested that basophils might participate in murine contact sensitivity.

Inhibitory effect of transplanted syngeneic thymus fragments, thymus epithelium and thymocytes on the increased contact sensitivity reaction in the adult thymectomized mouse

Thymectomy in the adult mouse leads to an increased ability to develop contact sensitivity. The effect of different types of thymus grafts to adult thymectomized mice on contact sensitivity was studied in the present investigation. An inhibition was observed after transplantation either of uncultured thymus tissue, cultured thymus epithelium or of thymocytes. The results of the study favor the hypothesis that a continuous production of suppressor cells regulates contact sensitivity in the adult mouse.