Health-related quality of life of adult and adolescent patients living with alopecia areata in Australia.

INTRODUCTION: To understand the experiences of adolescent and adult patients living with alopecia areata (AA) in Australia regarding symptom severity and the impact on psychosocial well-being and work/classroom productivity. MATERIALS AND METHODS: A cross-sectional online patient survey among adolescent and adult patients diagnosed with AA was recruited via the Australia Alopecia Areata Foundation. Patient-reported outcomes were also assessed. RESULTS: A total of 337 patients (49 adolescents; 288 adults), with a mean ± standard deviation age of 14.7 ± 1.55 and 38.9 ± 13.31 years for adolescents and adults, respectively, were included. In the group with extensive hair loss (Scalp Hair Assessment Patient-Reported Outcome, categories 3 + 4, n = 172), we observed higher emotional symptom and activity limitation scores (Alopecia Areata Patient Priority Outcomes, emotional symptoms: adults 2.5 ± 1.03, adolescents 2.2 ± 1.15; activity limitations: adults 1.4 ± 1.15, adolescents 1.2 ± 0.99). Additionally, in adults, the Alopecia Areata Symptom Impact Scale global score was 4.0 ± 2.10 (symptoms subscale score 4.1 ± 1.91; interference subscale scores 3.8 ± 2.73). Hospital Anxiety and Depression Scale scores were high across participants, irrespective of hair loss extent (adults: anxiety 9.2 ± 3.85, depression 6.6 ± 3.95; adolescents: anxiety 9.7 ± 4.65, depression 5.2 ± 3.59). Work and classroom productivity were substantially impaired due to AA, with 70.5% of adults and 57.1% of adolescents reporting activity impairment, and overall work/classroom impairment reported at 39.2% and 44.9%, respectively. CONCLUSIONS: AA impacts the physical, emotional and psychosocial well-being of both adult and adolescent patients. More extensive hair loss more profoundly impacts those living with AA. Patients may benefit from patient-centred care approaches addressing the impact of hair loss on mental and emotional well-being, daily activities and work productivity.

Real-world evaluation of persistence, effectiveness and usage patterns of tofacitinib in treatment of psoriatic arthritis in Australia.

OBJECTIVES: To describe treatment patterns and persistence of tofacitinib, interleukin 17 inhibitors (IL-17Ai) and tumour necrosis factor inhibitors (TNFi), in patients with psoriatic arthritis (PsA). METHODS: Data from adult patients with PsA and who had received at least one prescription of tofacitinib, IL-17Ai or TNFi between May 2019 and September 2021 were sourced from the Australian OPAL dataset. Persistence, analysed via Kaplan-Meier methods, and propensity score matching between tofacitinib and bDMARD (IL-17Ai and TNFi) groups were conducted. RESULTS: Of 16,692 patients with PsA, 1486 (n = 406 tofacitinib, n = 416 IL-17Ai and n = 664 TNFi) were included. More females were in the tofacitinib group (75.4%) than in the IL-17Ai (61.1%) and TNFi (64.8%) groups. Overall, 19.2% of tofacitinib patients were first line, compared with 41.8% of IL-17Ai and 62.8% of TNFi patients. In the overall population, the median persistence was 16.5 months (95% CI 13.8 to 19.5 months), 17.7 months (95% CI 15.8 to 19.6 months) and 17.2 months (95% CI 14.9 to 20.5 months) in the tofacitinib, IL-17Ai and TNFi groups, respectively. Persistence was similar in the tofacitinib/IL-17Ai matched population; however, in the tofacitinib/TNFi matched population, persistence was longer in the tofacitinib group (18.7 months, 95% CI 15.6 to 21.4 months) compared with the TNFi group (12.2 months, 95% CI 19.9 to 14.9 months). CONCLUSIONS: In this Australian real-world dataset, tofacitinib was more frequently used in later lines and among a slightly higher proportion of female patients than IL-17Ai or TNFi. Overall, treatment persistence was similar for tofacitinib, IL-17Ai and TNFi, but tofacitinib exhibited longer persistence than TNFi in a matched population. Key Points • This is the first, large real-world study from Australia investigating the demographics, treatment patterns and comparative treatment persistence of patients with psoriatic arthritis (PsA) treated with tofacitinib and biologic disease-modifying drugs (bDMARDs). • The study suggests that tofacitinib is an effective intervention in PsA with at least comparable persistence to bDMARDs: tumour necrosis factor inhibitors (TNFi) and interleukin-17 A inhibitors (IL-17Ai).

Real-world evaluation of effectiveness, persistence, and usage patterns of monotherapy and combination therapy tofacitinib in treatment of rheumatoid arthritis in Australia.

OBJECTIVE: This study aimed to describe the real-world effectiveness and treatment persistence among patients with rheumatoid arthritis treated with monotherapy and combination therapy tofacitinib and biologic disease-modifying antirheumatic drugs (bDMARDs). METHODS: This was a post hoc analysis of a retrospective, non-interventional study that extracted data for patients treated with tofacitinib or bDMARDs from the Australian OPAL dataset between March 2015 and September 2018. Monotherapy tofacitinib and bDMARDs and combination therapy tofactinib and bDMARDs were propensity score matched and treatment effectiveness and persistence of the groups were evaluated. RESULTS: In the bDMARD and tofacitinib monotherapy and combination therapy matched populations there were 1300 bDMARD initiators (n = 564 monotherapy) and 650 tofacitinib initiators (n = 282 monotherapy). In the bDMARD and tofacitinib monotherapy matched groups, 62.9% and 66.7% were in DAS-28 CRP disease remission after 18 months of treatment, respectively. In the combination therapy bDMARD and tofacitinib groups, 50% and 58.9% were in DAS-28 CRP disease remission after 18 months, respectively. The median treatment persistence was similar between the monotherapy bDMARD and tofacitinib treatment groups (36.7 months (95% CI 27.4 to "not reached') and 34.2 months (95%CI 30.3 to "not reached") respectively) as well as the combination therapy bDMARD and tofacitinib groups (32.2 months (95% CI 25.7 to 34.4) and 32.7 months (95%CI 28.7 to "not reached", respectively). CONCLUSIONS: Patients receiving combination therapy with tofacitinib or bDMARDs had higher disease activity scores at index than patients receiving monotherapy. Monotherapy with tofacitinib or bDMARDs, and combination therapy with tofacitinib or bDMARDs demonstrated similar treatment effectiveness and persistence, respectively. Key Points • This study provides real-world evidence regarding effectiveness, treatment persistence, and treatment patterns, among patients with rheumatoid arthritis (RA) treated with monotherapy or combination therapy tofacitinib. • The study suggests that monotherapy and combination therapy tofacitinib is an effective intervention in RA with persistence and effectiveness comparable to bDMARDs.

Ulcerative Colitis Narrative findings: Australian survey data comparing patient and physician disease management views.

BACKGROUND AND AIM: The Global Ulcerative Colitis (UC) Narrative Survey aimed to evaluate the impact of UC, perceptions of UC burden, and management approaches. Here, we present data from patients and physicians in Australia. METHODS: Surveys, fielded by The Harris Poll, were completed by 215 patients with UC and 90 physicians, between August 2017 and February 2018. Surveys included questions on disease characteristics, impact on life, communication with physicians, and patient knowledge of UC. Results are presented descriptively from all respondents (with no imputation for missing data). RESULTS: Based on medication history, 84% of patients had moderate to severe UC. Diagnostic delay was on average 1.9 (SD 5.0) years and 48% of patients had waited ≥1 year for diagnosis. Nearly two-thirds (65%) of patients considered themselves to be in remission, with 97% also reporting a flare in the past year. The majority (92%) of patients were satisfied with their UC medication and, if their treatment made them feel "good enough," many (75%) would not consider an alternative. Most (90%) patients were satisfied with communication with their physician; however, only 48% felt comfortable raising emotional concerns. Both patients and physicians desired more time during routine appointments. Patients had gaps in their knowledge of UC, which physicians mostly recognized. CONCLUSIONS: The Australian survey results highlighted the diagnostic delay and burden of UC patients' experience, gaps in patients' knowledge of UC, and challenges in patient-physician communication. Compared with the overall Global UC Narrative Survey, patients in Australia reported a high burden of disease.

Patient Perceptions of Psoriatic Arthritis Management and Communication with Physicians in Australia: Results from a Patient Survey.

INTRODUCTION: The objective of this report was to evaluate perceptions of psoriatic arthritis (PsA) treatment and satisfaction with healthcare professional (HCP) communication among patients with PsA in Australia, compared with overall global perceptions. METHODS: Data were collected via a global and country-specific survey (The Harris Poll; November 2, 2017-March 12, 2018). Eligible patients were ≥ 18 years old, had been diagnosed with PsA > 1 year prior, had seen a rheumatologist or dermatologist within the past 12 months, and had previously received ≥ 1 conventional synthetic or biologic disease-modifying antirheumatic drug. Data reported by patients included baseline demographics, overall health, time since PsA diagnosis, PsA severity, satisfaction with current PsA medication and management, and experiences regarding communication with their HCP. Descriptive statistics were obtained. RESULTS: Most patients in Australia were very or somewhat satisfied with their PsA medication, and reported always or often taking their medication exactly as directed by their HCP. However, the majority still experienced symptoms, reported their overall health as poor or fair, and would change something about their PsA medication. While the majority of patients in Australia were satisfied with the communication with their HCP, most would prefer increased communication but some felt that asking too many questions would affect the quality of their care. Perceptions in Australia were similar to global perceptions. CONCLUSIONS: Although most patients with PsA in Australia were satisfied with their disease management and communication with their HCP, many still experienced symptoms, would change something about their PsA medication, and would prefer increased communication with their HCP.

Psoriatic arthritis (PsA) can cause tender and swollen joints. If not treated properly, the joint damage can get worse, until patients struggle to cope with everyday tasks. Patients and their doctors need to communicate well to successfully manage PsA. We used an online survey to ask patients in Australia how they feel about their PsA medication and the way they communicate with their doctor. These patients were adults who had had PsA for more than 1 year, had seen a specialist doctor in the past year, and had taken one or more prescription PsA medications. A total of 152 patients in Australia completed the survey. Most patients were very or somewhat satisfied with the PsA medication they were taking, and most always or often took it exactly as their doctor told them to. However, almost all patients still had symptoms, most said their overall health was poor or fair, and most would like to change something about their medication. While most patients were satisfied with the communication with their doctor about PsA, most wished they talked more with their doctor about their PsA and treatment goals, but some felt that asking too many questions would harm their quality of care. Patients in Australia had similar answers to patients who answered the survey in other countries. Although the survey was limited by the number of patients who responded, and whether patients answered questions properly, it suggests that patients and doctors need to communicate more closely to improve PsA management.

Real-world evaluation of effectiveness, persistence, and usage patterns of tofacitinib in treatment of rheumatoid arthritis in Australia.

INTRODUCTION: The aim of this study was to describe the real-world evidence for effectiveness, treatment persistence, and treatment patterns among patients in the community with rheumatoid arthritis treated with the JAK inhibitor tofacitinib. METHODS: This was a retrospective, non-interventional cohort study that extracted data for new users of tofacitinib or biologic disease-modifying antirheumatic drugs (bDMARDs) from the Australian Optimizing Patient outcomes in Australian RheumatoLogy (OPAL) dataset between March 2015 and September 2018. Patients were propensity score matched at a 1:2 tofacitinib to bDMARD ratio based on age, sex, and selected baseline treatment combinations. Treatment effectiveness was evaluated using disease status measures. Treatment persistence was calculated and the percentage of patients receiving monotherapy or combination therapy at treatment initiation was evaluated. RESULTS: Data from 2810 patients were extracted and 1950 patients were included in the matched population (1300 bDMARD initiators and 650 tofacitinib initiators). Patients were predominantly aged 55 to 74 years (57.8%) and female (81.2%). After 18 months of treatment, 52.4% and 57.8% of patients had achieved disease activity score (DAS) remission in the bDMARD and tofacitinib groups, respectively. The median treatment persistence for tofacitinib was similar to that for bDMARDs: 34.2 months (95% CI 32.2 to not reached) and 33.8 months (95% CI 28.8 to 40.4), respectively. In the overall population, more patients were prescribed tofacitinib as monotherapy (43.4%) compared with bDMARD monotherapy (33.4%). CONCLUSIONS: Tofacitinib demonstrated treatment effectiveness and persistence similar to bDMARDs. Overall, there was a trend for more use of tofacitinib as monotherapy than bDMARDs. Key Points • This study provides real-world evidence regarding effectiveness, treatment persistence, and treatment patterns, among patients with rheumatoid arthritis (RA) in the community being treated with tofacitinib. • The study suggests that tofacitinib is an effective and enduring intervention in RA with tofacitinib persistence and effectiveness comparable to bDMARDs.

Treatment outcomes in patients with seropositive versus seronegative rheumatoid arthritis in Phase III randomised clinical trials of tofacitinib.

Objectives: Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). We examined response to tofacitinib 5 or 10 mg two times a day in patients with seropositive vs seronegative RA. Methods: Data were pooled from five Phase III studies of conventional synthetic disease-modifying antirheumatic drug (csDMARD)- or biological DMARD-inadequate responders (ORAL Step [NCT00960440]; ORAL Scan [NCT00847613]; ORAL Solo [NCT00814307]; ORAL Sync [NCT00856544]; ORAL Standard [NCT00853385]). 'Serotype' subgroups were: anticyclic citrullinated peptide (CCP) and rheumatoid factor (RF) positive (anti-CCP+/RF+); anti-CCP+/RF negative (-); anti-CCP-/RF+; anti-CCP-/RF-. At month 3, ACR20/50/70 response rates, Disease Activity Score (DAS28-4[ESR])-defined remission (DAS28-4[ESR]<2.6) and low disease activity (LDA; DAS28-4[ESR]≤3.2), changes from baseline (CFB) in Health Assessment Questionnaire-Disability Index (HAQ-DI), Short Form-36 Health Survey (SF-36) physical functioning and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) were evaluated. Safety endpoints were compared. Results: Baseline demographics/characteristics were similar across subgroups. Tofacitinib significantly improved ACR20/50/70 response rates, DAS28-4(ESR) LDA rates and CFB in HAQ-DI and FACIT-F vs placebo across subgroups. More anti-CCP+/RF+ than anti-CCP-/RF- patients had ACR20/50/70 responses (ACR20/50: both tofacitinib doses; ACR70: 10 mg two times a day). SF-36 physical functioning improved in anti-CCP+/RF+, anti-CCP+/RF- and anti-CCP-/RF+ patients (both tofacitinib doses) and anti-CCP-/RF- patients (10 mg two times a day) vs placebo. More anti-CCP+/RF+ and anti-CCP+/RF- than anti-CCP-/RF- patients achieved DAS28-4(ESR) remission and LDA with tofacitinib 10 mg two times a day. Frequency of adverse events (AEs), serious AEs and discontinuations due to AEs were similar across subgroups. Conclusion: Generally, tofacitinib efficacy (ACR20/50/70 responses) and safety were similar across subgroups. DAS28-4(ESR) remission rates and SF-36 physical functioning appeared lower in anti-CCP- patients.

Tofacitinib 5 mg Twice Daily in Patients with Rheumatoid Arthritis and Inadequate Response to Disease-Modifying Antirheumatic Drugs: A Comprehensive Review of Phase 3 Efficacy and Safety.

BACKGROUND: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We performed a comprehensive review of phase 3 studies of tofacitinib 5 mg twice daily (BID) (approved dose in many countries) in patients with moderate to severe RA and inadequate response to prior disease-modifying antirheumatic drugs. METHODS: A search of PubMed and ClinicalTrials.gov identified 5 studies: ORAL Solo (NCT00814307), ORAL Sync (NCT00856544), ORAL Standard (included adalimumab 40 mg once every 2 weeks; NCT00853385), ORAL Scan (NCT00847613), and ORAL Step (NCT00960440). Efficacy and safety data for tofacitinib 5 mg BID, placebo, and adalimumab were analyzed. RESULTS: Across the 5 studies, 1216 patients received tofacitinib 5 mg BID, 681 received placebo, and 204 received adalimumab. At month 3, tofacitinib demonstrated significantly higher 20%, 50%, and 70% improvement in American College of Rheumatology response criteria (ACR20, ACR50, and ACR70, respectively) response rates, greater improvement in Health Assessment Questionnaire-Disability Index, and a higher proportion of Disease Activity Score-defined remission than placebo. Frequencies of adverse events (AEs), serious AEs, and discontinuations due to AEs were similar for tofacitinib and placebo at month 3; serious infection events were more frequent for tofacitinib. In ORAL Standard, although not powered for formal comparisons, tofacitinib and adalimumab had numerically similar efficacy and AEs; serious AEs and serious infection events were more frequent with tofacitinib. CONCLUSIONS: Tofacitinib 5 mg BID reduced RA signs and symptoms and improved physical function versus placebo in patients with inadequate response to prior disease-modifying antirheumatic drugs. Tofacitinib 5 mg BID had a consistent, manageable safety profile across studies, with no new safety signals identified.

Tofacitinib, an Oral Janus Kinase Inhibitor: Pooled Efficacy and Safety Analyses in an Australian Rheumatoid Arthritis Population.

INTRODUCTION: In Australia, there is an unmet need for improved treatments for rheumatoid arthritis (RA). Tofacitinib is an oral Janus kinase inhibitor for the treatment of RA. To provide an overview of key study outcomes for tofacitinib in Australian patients, we analyzed the efficacy and safety of tofacitinib in the Australian subpopulation of global RA phase III and long-term extension (LTE) studies. METHODS: Data were pooled from the Australian subpopulation of four phase III studies and one LTE study (database not locked at cut-off date: January 2016). Patients in the phase III studies received tofacitinib 5 or 10 mg twice daily (BID), placebo (advancing to tofacitinib at months 3 or 6), or adalimumab, with background methotrexate or conventional synthetic disease-modifying antirheumatic drugs. Patients in the LTE study received tofacitinib 5 or 10 mg BID. Efficacy endpoints were American College of Rheumatology (ACR) 20/50/70 response rates, and change from baseline in the Disease Activity Score in 28 joints, erythrocyte sedimentation rate [DAS28-4(ESR)] and Health Assessment Questionnaire-Disability Index (HAQ-DI) scores. Safety endpoints included incidence of adverse events (AEs), serious AEs, and discontinuations due to AEs. AEs of special interest and laboratory parameters were analyzed in the LTE study. RESULTS: Across phase III studies (N = 100), ACR response rates and improvements in DAS28-4(ESR) and HAQ-DI scores were numerically greater with tofacitinib vs. placebo at month 3, and increased until month 12. The results were sustained in the LTE study (N = 99) after 60 months' observation. In general, the efficacy and safety profiles of tofacitinib were similar to those of the global RA population. CONCLUSIONS: In Australian patients with RA, tofacitinib therapy demonstrated sustained efficacy and consistent safety over ≥ 60 months' treatment. FUNDING: Pfizer Inc. TRIAL REGISTRATION NUMBERS (ALL CLINICALTRIALS.GOV): NCT00960440; NCT00847613; NCT00856544; NCT00853385; NCT00413699.

Strategies for anti-coccidial prophylaxis.

Coccidiosis, a serious disease resulting from infection with parasitic protozoa of the genus Eimeria, causes significant economic losses to the poultry industry, where intensive rearing facilitates transmission of infectious oocysts via the fecal/oral route. Current control relies primarily on prophylactic drugs in feed but, whilst cost effective, the rise of drug resistance and public demands for residue-free meat has encouraged development of alternative control strategies. Chickens that recover from infection with Eimeria develop solid immunity that is directed against the early asexual stages of the parasite life cycle. This has allowed development of a number of vaccines that utilize deliberate infection with controlled doses of virulent oocysts or reproductively attenuated lines of Eimeria. The latter are immunogenic but non-pathogenic. The realization that both prophylactic drugs and attenuated vaccines control but do not eradicate infection with Eimeria encouraged development of a vaccine based upon maternal immunity. Laying hens exposed to Eimeria are able to transfer protective antibodies to hatchlings via egg yolks and these antibodies have been used to identify parasite proteins that are conserved across the genus. When delivered maternally, these provide an economical means of preventing coccidiosis, offering immediate protection to newly hatched chicks.

Characterisation of the antigenic and immunogenic properties of bacterially expressed, sexual stage antigens of the coccidian parasite, Eimeria maxima.

Coccidiosis in poultry is caused by the intestinal parasite Eimeria; it causes significant financial losses to the commercial poultry industry worldwide. CoxAbic is the first commercially available subunit vaccine against coccidiosis. The vaccine consists of affinity purified sexual stage (gametocyte) antigens (APGA) isolated from Eimeria maxima. Production of this vaccine is time-consuming and laborious and, therefore, a recombinant subunit vaccine substitute for CoxAbic is desirable. The genes encoding the two immunodominant components of CoxAbic, gam56 and gam82, were cloned into the bacterial expression vector, pTRCHisB, and the proteins expressed and purified. Both recombinant proteins were recognised by protective chicken antibodies that were raised to APGA, by immunoblotting. In a competitive ELISA, a combination of the recombinant proteins inhibited the binding of anti-APGA antibodies to APGA by 76%, which was comparable to the inhibition of 98% observed when APGA was used as the competing protein in the assay. In two breeds of chicken (Australorp and Cobb500), the recombinant proteins alone, or in combination, elicited a dose-dependent, antibody response that recognised APGA by ELISA, and gametocytes by immunoblotting. Together, the results suggested that the development of a recombinant subunit vaccine that maintains the antigenic and immunogenic properties of the native protein vaccine, CoxAbic, is feasible.

Eimeria maxima TRAP family protein EmTFP250: subcellular localisation and induction of immune responses by immunisation with a recombinant C-terminal derivative.

EmTFP250 is a high molecular mass, asexual stage antigen from Eimeria maxima strongly associated with maternally derived immunity to this protozoan parasite in hatchling chickens. Cloning and sequence analysis has predicted the antigen to be a novel member of the thrombospondin-related anonymous protein (TRAP) family of apicomplexan parasites. Members of the TRAP family are microneme proteins and are associated with host cell invasion and apicomplexan gliding motility. In order to assess the immunogenicity of EmTFP250, a C-terminal derivative encoding a low complex, hydrophilic region and putative transmembrane domain/cytosolic tail was expressed in a bacterial host system. The recombinant protein was used to immunise mice and chickens and found to induce strong IgG responses in both animal models as determined by specific ELISAs. Using Western blotting, protective maternal IgG antibodies previously shown to recognise native EmTFP250 recognised the recombinant protein and, in addition, antibodies raised against the recombinant protein were shown to recognise native EmTFP250. Localisation studies employing immuno-light microscopy and immuno-electron microscopy showed that antibodies to the recombinant protein specifically labeled micronemes within merozoites of E. maxima. Furthermore, antibodies to the recombinant EmTFP250 derivative showed similar labeling of micronemes within merozoites of Eimeria tenella. This study is further suggestive of a functional importance for EmTFP250 and underscores its potential as a candidate for a recombinant vaccine targeting coccidiosis in chickens.

Molecular characterisation of EmTFP250: a novel member of the TRAP protein family in Eimeria maxima.

We have previously described a high molecular mass, asexual stage antigen from Eimeria maxima (EmTFP250), implicated as a target of maternal antibodies produced by breeding hens infected with this protozoan parasite. Following partial purification of the protein by ion exchange chromatography, N-terminal and internal peptide sequences were generated and used in the design of degenerate PCR primers. Using a rapid amplification of cDNA ends PCR-based strategy, the cDNA encoding EmTFP250 has been cloned and sequenced. Translation predicts a mature polypeptide with a molecular mass of 246kDa and an isoelectric point of 4.2. Analysis of the amino acid sequence has revealed a novel member of the TRAP (thrombospondin-related anonymous protein) family, containing 16 thrombospondin type-1 repeats and 31 epidermal growth factor-like calcium binding domains. EmTFP250 also contains two low complex, hydrophilic regions rich in glutamic acid and glycine residues, and a transmembrane domain/cytosolic tail associated with parasite gliding motility that is highly conserved within apicomplexan microneme proteins. The protein has 61% identity (71% similarity) with EtMIC4, a 218kDa microneme protein of Eimeria tenella also rich in epidermal growth factor-like and thrombospondin type-1 domains. Using Southern blotting, the gene encoding EmTFP250 has been determined to be present as a single copy within the genome, and reverse transcriptase-PCR has shown that expression is confined to the asexual stages of development. By employing a PCR-based method, a region of the E. maxima Houghton strain EmTFP250 gene was found conserved in Australian isolates of several (at least four) Eimeria species that parasitise chickens. The characterisation of EmTFP250 adds to the expanding apicomplexan TRAP family and suggests a functional significance for the protein.

Functional genomics of gam56: characterisation of the role of a 56 kilodalton sexual stage antigen in oocyst wall formation in Eimeria maxima.

Gam56 (M(r) 56,000) is an antigen found in the sexual (macrogametocyte) stage of the intestinal parasite Eimeria maxima that is implicated in protective immunity. The gene (gam56) encoding this protein was cloned and sequenced. It is a single-copy, intronless gene, that localises to a 1,754 bp transcript, and is first detected at 120 h p.i. The gene predicts two distinct protein domains; a tyrosine-serine rich region, composed of amino acids implicated in oocyst wall formation in Eimeria spp., and a proline-methionine rich region often detected in extensins, protein components of plant cell walls. The tyrosine-serine rich region predicts a secondary structure commonly seen in the structural protein fibroin, a component of the cocoon of the caterpillar Bombyx mori. The inference that gam56 is a structural component of the oocyst wall was confirmed when a specific antibody to gam56 recognised the wall forming bodies in macrogametocytes, and the walls of oocysts and sporocysts. Together, these data identify a developmentally regulated, sexual stage gene in E. maxima that shares primary and secondary structure features in common with intrinsic structural proteins in other parasites such as Schistosoma mansoni and Fasciola hepatica, and other organisms across different phyla, including the caterpillar Bombyx mori. In addition, these findings provide evidence for the molecular mechanisms underlying oocyst wall formation in Eimeria and the role of gametocyte antigens in this process.