Long-term health-care utilisation in older patients with cancer and the association with the Geriatric 8 screening tool: a retrospective analysis using linked clinical and population-based data in Belgium

BACKGROUND

Little evidence is available on the long-term health-care utilisation of older patients with cancer and whether this is associated with geriatric screening results. We aimed to evaluate long-term health-care utilisation among older patients after cancer diagnosis and the association with baseline Geriatric 8 (G8) screening results.

METHODS

For this retrospective analysis, we included data from three cohort studies for patients (aged ≥70 years) with a new cancer diagnosis who underwent G8 screening between Oct 19, 2009 and Feb 27, 2015, and who survived more than 3 months after G8 screening. The clinical data were linked to cancer registry and health-care reimbursement data for long-term follow-up. The occurrence of outcomes (inpatient hospital admissions, emergency department visits, use of intensive care, contacts with general practitioner [GP], contacts with a specialist, use of home care, and nursing home admissions) was assessed in the 3 years after G8 screening. We assessed the association between outcomes and baseline G8 score (normal score [>14] or abnormal [≤14]) using adjusted rate ratios (aRRs) calculated from Poisson regression and using cumulative incidence calculated as a time-to-event analysis with the Kaplan-Meier method.

FINDINGS

7556 patients had a new cancer diagnosis, of whom 6391 patients (median age 77 years [IQR 74-82]) met inclusion criteria and were included. 4110 (64·3%) of 6391 patients had an abnormal baseline G8 score (≤14 of 17 points). In the first 3 months after G8 screening, health-care utilisation peaked and then decreased over time, with the exception of GP contacts and home care days, which remained high throughout the 3-year follow-up period. Compared with patients with a normal baseline G8 score, patients with an abnormal baseline G8 score had more hospital admissions (aRR 1·20 [95% CI 1·15-1·25]; p<0·0001), hospital days (1·66 [1·64-1·68]; p<0·0001), emergency department visits (1·42 [1·34-1·52]; p<0·0001), intensive care days (1·49 [1·39-1·60]; p<0·0001), general practitioner contacts (1·19 [1·17-1·20]; p<0·0001), home care days (1·59 [1·58-1·60]; p<0·0001), and nursing home admissions (16·7% vs 3·1%; p<0·0001) in the 3-year follow-up period. At 3 years, of the 2281 patients with a normal baseline G8 score, 1421 (62·3%) continued to live at home independently and 503 (22·0%) had died. Of the 4110 patients with an abnormal baseline G8 score, 1057 (25·7%) continued to live at home independently and 2191 (53·3%) had died.

INTERPRETATION

An abnormal G8 score at cancer diagnosis was associated with increased health-care utilisation in the subsequent 3 years among patients who survived longer than 3 months.

FUNDING

Stand up to Cancer, the Flemish Cancer Society.

End-of-Life Care in the Last Three Months before Death in Older Patients with Cancer in Belgium: A Large Retrospective Cohort Study Using Data Linkage

This study aims to describe end-of-life (EOL) care in older patients with cancer and investigate the association between geriatric assessment (GA) results and specialized palliative care (SPC) use. Older patients with a new cancer diagnosis (2009-2015) originally included in a previous multicentric study were selected if they died before the end of follow-up (2019). At the time of cancer diagnosis, patients underwent geriatric screening with Geriatric 8 (G8) followed by GA in case of a G8 score ≤14/17. These data were linked to the cancer registry and healthcare reimbursement data for follow-up. EOL care was assessed in the last three months before death, and associations were analyzed using logistic regression. A total of 3546 deceased older patients with cancer with a median age of 79 years at diagnosis were included. Breast, colon, and lung cancer were the most common diagnoses. In the last three months of life, 76.3% were hospitalized, 49.1% had an emergency department visit, and 43.5% received SPC. In total, 55.0% died in the hospital (38.5% in a non-palliative care unit and 16.4% in a palliative care unit). In multivariable analyses, functional and cognitive impairment at cancer diagnosis was associated with less SPC. Further research on optimizing EOL healthcare utilization and broadening access to SPC is needed.

Linking clinical and population-based data in older patients with cancer in Belgium: Feasibility and clinical outcomes

INTRODUCTION

Geriatric screening and geriatric assessment (GS/GA) have proven their benefits in the care for older patients with cancer. However, less is known about the predictive value of GS/GA for outcomes. To research this, clinical data on GS/GA can be enriched with population-based data. In this article we describe the methods and feasibility of data linkage, and first clinical outcomes (GS/GA results and overall survival).

MATERIALS AND METHODS

A large cohort study consisting of patients aged ≥70 years with a new cancer diagnosis was established using linked data from clinical and population-based databases. Clinical data were derived from a previous prospective study where older patients with cancer were screened with G8, followed by GA in case of an abnormal result (GS/GA study; 2009-2015). These data were linked to cancer registration data from the Belgian Cancer Registry (BCR), reimbursement data of the health insurance companies (InterMutualistic Agency, IMA), and hospital discharge data (Technical Cell, TCT). Cox regression analyses were conducted to evaluate the prognostic value of the G8 geriatric screening tool.

RESULTS

Of the 8067 eligible patients with a new cancer diagnosis, linkage of data from the GS/GA study and data from the BCR was successful for 93.7%, resulting in a cohort of 7556 patients available for the current analysis. Further linkage with the IMA and TCT database resulted in a cohort of 7314 patients (96.8%). Based on G8 geriatric screening, 67.9% of the patients had a geriatric risk profile. Malnutrition and functional dependence were the most common GA-identified risk factors. An abnormal baseline G8 score (≤14/17) was associated with lower overall survival (adjusted HR [aHR] = 1.62 [1.50-1.75], p < 0.001).

DISCUSSION

Linking clinical and population-based databases for older patients with cancer has shown to be feasible. The GS/GA results at cancer diagnosis demonstrate the vulnerability of this population and the G8 score showed prognostic value for overall survival. The established cohort of almost 8000 patients with long-term follow-up will serve as a basis in the future for detailed analyses on long-term outcomes beyond survival.

Incidence of falls and fall-related injuries and their predictive factors in frail older persons with cancer: a multicenter study

Background

Falls and fall-related injuries are a major public health problem. Data on falls in older persons with cancer is limited and robust data on falls within those with a frailty profile are missing. The aim of this study is to investigate the incidence and predictive factors for falls and fall-related injuries in frail older persons with cancer.

Methods

This study is a secondary data analysis from data previously collected in a large prospective multicenter observational cohort study in older persons with cancer in 22 Belgian hospitals (November 2012–February 2015). Patients ≥70 years with a malignant tumor and a frailty profile based on an abnormal G8 score were included upon treatment decision and evaluated with a Geriatric Assessment (GA). At follow-up, data on falls and fall-related injuries were documented.

Results

At baseline 2141 (37.2%) of 5759 included patients reported at least one fall in the past 12 months, 1427 patients (66.7%) sustained an injury. Fall-related data of 3681 patients were available at follow-up and at least one fall was reported by 769 patients (20.9%) at follow-up, of whom 289 (37.6%) fell more than once and a fall-related injury was reported by 484 patients (62.9%). Fear of falling was reported in 47.4% of the patients at baseline and in 55.6% of the patients at follow-up. In multivariable analysis, sex and falls history in the past 12 months were predictive factors for both falls and fall-related injuries at follow-up. Other predictive factors for falls, were risk for depression, cognitive impairment, dependency in activities of daily living, fear of falling, and use of professional home care.

Conclusion

Given the high number of falls and fall-related injuries and high prevalence of fear of falling, multifactorial falls risk assessment and management programs should be integrated in the care of frail older persons with cancer. Further studies with long-term follow-up, subsequent impact on cancer treatment and interventions for fall prevention, and integration of other important topics like medication and circumstances of a fall, are warranted.

Trial registration

B322201215495.

Functional status in older patients with cancer and a frailty risk profile: A multicenter observational study

INTRODUCTION

Functional status (FS) and frailty are significant concerns for older adults, especially those with cancer. Data on FS (Activities of Daily Living [ADL]; Instrumental Activities of Daily Living [IADL]) and its evolution during cancer treatment in older patients and a frailty risk profile are scarce. Therefore, this study examines FS and its evolution in older patients with cancer and a frailty risk profile and investigates characteristics associated with functional decline.

MATERIAL AND METHODS

This secondary data-analysis, focusing on FS, uses data from a large prospective multicenter observational cohort study. Patients ≥70 years with a solid tumor and a frailty risk profile based on the G8 screening tool (score ≤ 14) were included. A geriatric assessment was performed including evaluation of FS based on ADL and IADL. At approximately three months of follow-up, FS was reassessed. Univariable and multivariable logistic regression analyses were used to identify predictive factors for functional decline in ADL and IADL.

RESULTS

Data on ADL and IADL were available at baseline and follow-up in 3388 patients. At baseline 1886 (55.7%) patients were dependent for ADL, whereas 2085 (61.5%) patients were dependent at follow-up. Functional decline was observed in 23.6% of patients. For IADL 2218 (65.5%) patients were dependent for IADL, whereas 2591 (76.5%) patients were dependent at follow-up. Functional decline in IADL was observed in 41.0% of patients. In multivariable analysis, disease stage III or IV, comorbidities, falls history in the past twelve months, and FS measured by IADL were predictive factors for functional decline in both ADL and IADL. Other predictive factors for functional decline in ADL were polypharmacy, Eastern Cooperative Oncology Group-Performance Status (ECOG-PS) score 2-4, and cognitive impairment, and for functional decline in IADL were female sex, fatigue, and risk for depression.

DISCUSSION

Functional impairments are frequent in older persons with cancer and a frailty risk profile, and several characteristics are identified that are significantly associated with functional decline. Therefore, FS is an essential part of the geriatric assessment which should be standard of care for this patient population. Next step is to proceed with directed interventions with the aim to limit the risk of functional decline as much as possible.

General practitioner contacts, hospitalizations, and nursing home transfers in older patients up to three years after new cancer diagnosis: Results from a large data linkage cohort study

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Background: Long-term outcomes after cancer diagnosis in older persons are largely unexplored because of limited follow-up in clinical studies. By linking clinical data with population-based data, studying long-term outcomes in large cohorts becomes feasible. The current study aims to explore long-term outcomes in the care trajectory of older patients with cancer and to assess their association with baseline geriatric screening and assessment (GS/GA) results. Methods: A large cohort study of older patients with a new cancer diagnosis was set up by linking clinical, cancer registry and administrative health data based on a unique patient identifier. Clinical data were derived from a previously performed prospective multicentric Belgian study (2009-2015). Patients aged ≥ 70 years were screened with G8 followed by GA in case of an abnormal result (≤14/17). Tumor characteristics and vital status were derived from cancer registry data and long-term outcomes (general practitioner (GP) contacts, hospitalizations and nursing home transfers) from administrative health data. In patients that survived at least 3 months since inclusion, outcomes were assessed from the day after inclusion until 3 years after. Event rates were calculated using person-time at risk to allow for varying follow-up time. Patients were censored 3 months before death to exclude influence of end-of-life care. Results: After data linkage, 6,391 older patients with a new cancer diagnosis were available for this analysis. The median age was 77 (range: 70–100) and 59.8% was female. Diagnoses included solid (92.8%) and hematologic malignancies (7.2%). In the patients with a solid tumor, breast, colorectal and lung cancer were the most common and 20.1% of patients had stage IV. 64.3% of patients had an abnormal baseline G8 score. During the 3 year follow-up, 2,602 (40.7%) of the included patients died. In these 3 years, 5,985 (95.2%) patients had at least one contact with a GP and 4,634 (72.5%) had at least one new hospital admission (event rates in Table 1). Of the 3,724 patients living independently at inclusion and still alive after 3 years, 281 (7.5%) had been transferred to a nursing home and of those, 240 (85.4%) patients had an abnormal baseline G8 score. Conclusions: Older patients with an abnormal baseline G8 score have more GP contacts, hospital admissions and nursing home transfers in the 3 years following a new cancer diagnosis compared to patients with normal baseline G8 score. Baseline G8 could help identify patients at risk for higher long-term healthcare utilization.[Table: see text]

Safety of systemic anti-cancer treatment in oncology patients with non-severe COVID-19: a cohort study

Background

The viral pandemic coronavirus disease 2019 (COVID-19) has disrupted cancer patient management around the world. Most reported data relate to incidence, risk factors, and outcome of severe COVID-19. The safety of systemic anti-cancer therapy in oncology patients with non-severe COVID-19 is an important matter in daily practice.

Methods

ONCOSARS-1 was a single-center, academic observational study. Adult patients with solid tumors treated in the oncology day unit with systemic anti-cancer therapy during the initial phase of the COVID-19 pandemic in Belgium were prospectively included. All patients (n = 363) underwent severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) serological testing after the first peak of the pandemic in Belgium. Additionally, 141 of these patients also had a SARS-CoV-2 RT-PCR test during the pandemic. The main objective was to retrospectively determine the safety of systemic cancer treatment, measured by the rate of adverse events according to the Common Terminology Criteria for Adverse Events, in SARS-CoV-2-positive patients compared with SARS-CoV-2-negative patients.

Results

Twenty-two (6%) of the 363 eligible patients were positive for SARS-CoV-2 by RT-PCR and/or serology. Of these, three required transient oxygen supplementation, but none required admission to the intensive care unit. Hematotoxicity was the only adverse event more frequently observed in SARS-CoV-2 -positive patients than in SARS-CoV-2-negative patients: 73% vs 35% (P < 0.001). This association remained significant (odds ratio (OR) 4.1, P = 0.009) even after adjusting for performance status and type of systemic treatment. Hematological adverse events led to more treatment delays for the SARS-CoV-2-positive group: 55% vs 20% (P < 0.001). Median duration of treatment interruption was similar between the two groups: 14 and 11 days, respectively. Febrile neutropenia, infections unrelated to COVID-19, and bleeding events occurred at a low rate in the SARS-CoV-2-positive patients.

Conclusion

Systemic anti-cancer therapy appeared safe in ambulatory oncology patients treated during the COVID-19 pandemic. There were, however, more treatment delays in the SARS-CoV-2-positive population, mainly due to a higher rate of hematological adverse events.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08349-8.

Unplanned hospitalizations in older patients with cancer: Occurrence and predictive factors

BACKGROUND

This study aims to investigate the occurrence of unplanned hospitalizations in older patients with cancer and to determine predictive factors.

METHODS

A prospective Belgian multicentre (n = 22), observational cohort study was performed. Patients ≥70 years with a malignant tumor were included. Patients underwent G8 screening followed by geriatric assessment (GA) if abnormal at baseline and were followed for unplanned hospitalizations at approximately three months. Uni- and multivariable regression models were performed to determine predictive factors associated with unplanned hospitalizations in older patients with an abnormal G8.

RESULTS

In total, 7763 patients were included in the current analysis of which 2409 (31%) patients with a normal G8 score and 5354 (69%) with an abnormal G8 score. Patients with an abnormal G8 were hospitalized more frequently than patients with a normal G8 (22.9% versus 12.4%; p < 0.0001). Reasons for unplanned hospitalizations were most frequently cancer related (25.7%) or cancer therapy related (28%). In multivariable analysis, predictive factors for unplanned hospitalizations in older patients with cancer and an abnormal G8 were female gender, absence of surgery, chemotherapy, ADL dependency, malnutrition and presence of comorbidities.

CONCLUSION

Older patients with cancer and an abnormal G8 screening present a higher risk (23%) for unplanned hospitalizations. Predictive factors for these patients were identified and include not only patient and treatment related factors but also GA related factors.

Adherence to geriatric assessment-based recommendations in older patients with cancer: a multicenter prospective cohort study in Belgium

Background

In the general older population, geriatric assessment (GA)-guided treatment plans can improve overall survival, quality of life and functional status (FS). In GA-related research in geriatric oncology, studies mainly focused on geriatric screening and GA but not on geriatric recommendations, interventions and follow-up. The aim of this study was to investigate the adherence to geriatric recommendations and subsequent actions undertaken in older patients with cancer.

Patient and methods

A prospective Belgian multicenter (N = 22) cohort study included patients ≥70 years with a malignant tumor upon oncologic treatment decision. Patients with an abnormal result on the geriatric screening (G8 ≤14/17) underwent GA. Geriatric recommendations were formulated based on GA results. At follow-up the adherence to geriatric recommendations was documented including a description of actions undertaken.

Results

From November 2012 till February 2015, G8 screening was carried out in 8451 patients, of which 5838 patients had an abnormal result. Geriatric recommendations data were available for 5631 patients. Geriatric recommendations were made for 4459 patients. Geriatric interventions data were available for 4167 patients. A total of 12 384 geriatric recommendations were made. At least one different geriatric recommendation was implemented in 2874 patients. A dietician, social worker and geriatrician intervened most frequently for problems detected on the nutritional, social and functional domain. A total of 7569 actions were undertaken for a total of 5725 geriatric interventions, most frequently nutritional support and supplements, extended home care and psychological support.

Conclusions

This large-scale Belgian study focuses on the adherence to geriatric recommendations and subsequent actions undertaken and contributes to the optimal management of older patients with cancer. We identified the domains for which geriatric recommendations are most frequently made and adhered to, and which referrals to other health care workers and facilities are frequently applied in the multidisciplinary approach of older patients with cancer.

VAV1 regulates experimental autoimmune arthritis and is associated with anti-CCP negative rheumatoid arthritis

Rheumatoid arthritis (RA) patients can be stratified into two subgroups defined by the presence or absence of antibodies against citrullinated circular peptides (anti-CCP) with most of the genetic association found in anti-CCP positive RA. Here we addressed the role of VAV1, previously associated to multiple sclerosis (MS), in the pathogenesis of RA in experimental models and in a genetic association study. Experimental arthritis triggered by pristane or collagen type II was induced in DA rats and in the DA.BN-R25 congenic line that carries a polymorphism in Vav1. Difference in arthritis severity was observed only after immunization with pristane. In a case-control study, 34 SNPs from VAV1 locus were analyzed by Immunochip genotyping in 11475 RA patients (7573 anti-CCP positive and 3902 negative) and 15,870 controls in six cohorts of European Caucasians. A combination of the previous MS-associated haplotype and two additional SNPs was associated with anti-CCP negative RA (alleles G-G-A-A of rs682626-rs2546133-rs2617822-rs12979659, OR=1.13, P=1.27 × 10^-5). The same markers also contributed to activity of RA at baseline with the strongest association in the anti-CCP negative group for the rs682626-rs12979659 G-A haplotype (β=-0.283, P=0.0048). Our study suggests a role for VAV1 and T-cell signaling in the pathology of anti-CCP-negative RA.

Unusual pulmonary toxicity of ipilimumab treated by macrolides

INTRODUCTION

Ipilimumab is a human monoclonal antibody that blocks cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) and promotes antitumour immunity. It has recently been approved for the treatment of metastatic melanoma patients. Ipilimumab is now widely used and the spectrum of side effects because of autoimmunity is expanding. To our knowledge, this is the first report of an ipilimumab-induced pulmonary immune-related adverse event (irAE) that was successfully treated by macrolides without corticosteroids.

CASE REPORT

A 77-year-old man with metastatic melanoma developed fever, cough and dyspnoea soon after the start of ipilimumab treatment leading to the diagnosis of a bronchiolitis obliterans organising pneumonia (BOOP). The patient was treated with clarithromycin allowing a good clinical and radiological evolution.

CONCLUSION

Macrolides seem to have a therapeutic anti-inflammatory potential in the case of mild to moderate pulmonary ipilimumab-induced irAEs. However, more data are needed to confirm macrolides use in this indication in clinical practice and corticosteroids remain the gold standard treatment in case of severe ipilimumab-associated irAEs.

Treatment with two different doses of sonidegib in patients with locally advanced or metastatic basal cell carcinoma (BOLT): a multicentre, randomised, double-blind phase 2 trial

BACKGROUND

Patients with advanced basal cell carcinoma have limited treatment options. Hedgehog pathway signalling is aberrantly activated in around 95% of tumours. We assessed the antitumour activity of sonidegib, a Hedgehog signalling inhibitor, in patients with advanced basal cell carcinoma.

METHODS

BOLT is an ongoing multicentre, randomised, double-blind, phase 2 trial. Eligible patients had locally advanced basal cell carcinoma not amenable to curative surgery or radiation or metastatic basal cell carcinoma. Patients were randomised via an automated system in a 1:2 ratio to receive 200 mg or 800 mg oral sonidegib daily, stratified by disease, histological subtype, and geographical region. The primary endpoint was the proportion of patients who achieved an objective response, assessed in the primary efficacy analysis population (patients with fully assessable locally advanced disease and all those with metastatic disease) with data collected up to 6 months after randomisation of the last patient. This trial is registered with ClinicalTrials.gov, number NCT01327053.

FINDINGS

Between July 20, 2011, and Jan 10, 2013, we enrolled 230 patients, 79 in the 200 mg sonidegib group, and 151 in the 800 mg sonidegib group. Median follow-up was 13·9 months (IQR 10·1-17·3). In the primary efficacy analysis population, 20 (36%, 95% CI 24-50) of 55 patients receiving 200 mg sonidegib and 39 (34%, 25-43) of 116 receiving 800 mg sonidegib achieved an objective response. In the 200 mg sonidegib group, 18 (43%, 95% CI 28-59) patients who achieved an objective response, as assessed by central review, were noted among the 42 with locally advanced basal cell carcinoma and two (15%, 2-45) among the 13 with metastatic disease. In the 800 mg group, 35 (38%, 95% CI 28-48) of 93 patients with locally advanced disease had an objective response, as assessed by central review, as did four (17%, 5-39) of 23 with metastatic disease. Fewer adverse events leading to dose interruptions or reductions (25 [32%] of 79 patients vs 90 [60%] of 150) or treatment discontinuation (17 [22%] vs 54 [36%]) occurred in patients in the 200 mg group than in the 800 mg group. The most common grade 3-4 adverse events were raised creatine kinase (five [6%] in the 200 mg group vs 19 [13%] in the 800 mg group) and lipase concentration (four [5%] vs eight [5%]). Serious adverse events occurred in 11 (14%) of 79 patients in the 200 mg group and 45 (30%) of 150 patients in the 800 mg group.

INTERPRETATION

The benefit-to-risk profile of 200 mg sonidegib might offer a new treatment option for patients with advanced basal cell carcinoma, a population that is difficult to treat.

FUNDING

Novartis Pharmaceuticals Corporation.

Lack of linkage and association of adrenomedullin and its receptor genes in French Caucasian rheumatoid arthritis trio families

OBJECTIVE

Rheumatoid arthritis (RA) is characterized by hyperplasia of fibro-blast-like synoviocytes (FLSs), in part due to apoptosis resistance. Adrenomedullin, an anti-apoptotic peptide, is secreted more by RA than osteoarthritis FLSs. Adrenomedullin binds to a heterodimeric functional receptor, of calcitonin receptor-like receptor (CRLR) coupled with a receptor activity-modifying protein-2 (RAMP-2), which is also overexpressed by rheumatoid synoviocytes. Since adrenomedullin decreases RA FLS apoptosis, possibly contributing to the development of pannus, study of adrenomedullin and its receptor genes might reveal a linkage and association in French Caucasian RA trio families.

METHODS

Within each of 100 families, one RA-affected patient and both parents underwent genotyping for polymorphisms of adrenomedullin, CRLR and RAMP-2, by PCR-restricted fragment-length polymorphism (RFLP) or Taqman 5' allelic discrimination assay. Statistical analysis relied on the transmission disequilibrium test, the affected family-based controls and the genotype relative risk. Haplotypes of CRLR were inferred, and linkage and association studies were performed.

RESULTS

No significant transmission disequilibrium or association between the three genes and RA was observed. CRLR haplotypes revealed two major haplotypes, but no significant linkage with RA.

CONCLUSION

Our findings provided no significant linkage or association of adrenomedullin and CRLR-RAMP-2 genes with RA in the studied trio families. The two CRLR polymorphisms rs3771076 and rs3771084 should be investigated in larger samples.

Contribution of PTPN22 1858T, TNFRII 196R and HLA-shared epitope alleles with rheumatoid factor and anti-citrullinated protein antibodies to very early rheumatoid arthritis diagnosis

OBJECTIVES

To evaluate the predictive value of TNFRII 196R, PTPN22 1858T and HLA-shared epitope (SE) alleles, RFs and anti-citrullinated protein antibodies (ACPAs) for RA diagnosis in a cohort of patients with very early arthritis.

METHODS

We followed up 284 patients who had swelling of at least two joints that had persisted for longer than 4 weeks but had been evolving for <6 months. At 2 yrs, patients were classified as having RA or non-RA rheumatic diseases according to the ACR criteria. Patients were genotyped with respect to TNFRII 196M/R and PTPN22 1858C/T polymorphisms and HLA-SE. The presence of IgA, IgG and IgM RF isotypes and ACPA was sought in sera collected at disease onset.

RESULTS

HLA-SE alleles alone, concomitant presence of TNFRII 196R and PTPN22 1858T alleles, IgA, IgG and IgM RF alone and ACPA were found to be significantly associated with RA diagnosis. Using logistic regression analysis, the concomitant presence of RF and ACPA at disease onset was the best association to predict RA diagnosis. In patients (n = 34) who did not fulfil the ACR criteria for RA at inclusion but who progressed to ACR positivity, the study of the genetic risk markers did not contribute to predict RA diagnosis at 2 yrs.

CONCLUSIONS

PTPN22 1858T, TNFRII 196R and HLA-SE alleles do not improve the predictive value of RF and ACPA for RA diagnosis in our cohort, and do not contribute to an earlier diagnosis in undifferentiated patients initially negative for RF and ACPA.

Contribution of PTPN22 1858T, TNFRII 196R and HLA-shared epitope alleles with rheumatoid factor and anti-citrullinated protein antibodies to very early rheumatoid arthritis diagnosis

OBJECTIVES

To evaluate the predictive value of TNFRII 196R, PTPN22 1858T and HLA-shared epitope (SE) alleles, RFs and anti-citrullinated protein antibodies (ACPAs) for RA diagnosis in a cohort of patients with very early arthritis.

METHODS

We followed up 284 patients who had swelling of at least two joints that had persisted for longer than 4 weeks but had been evolving for <6 months. At 2 yrs, patients were classified as having RA or non-RA rheumatic diseases according to the ACR criteria. Patients were genotyped with respect to TNFRII 196M/R and PTPN22 1858C/T polymorphisms and HLA-SE. The presence of IgA, IgG and IgM RF isotypes and ACPA was sought in sera collected at disease onset.

RESULTS

HLA-SE alleles alone, concomitant presence of TNFRII 196R and PTPN22 1858T alleles, IgA, IgG and IgM RF alone and ACPA were found to be significantly associated with RA diagnosis. Using logistic regression analysis, the concomitant presence of RF and ACPA at disease onset was the best association to predict RA diagnosis. In patients (n = 34) who did not fulfil the ACR criteria for RA at inclusion but who progressed to ACR positivity, the study of the genetic risk markers did not contribute to predict RA diagnosis at 2 yrs.

CONCLUSIONS

PTPN22 1858T, TNFRII 196R and HLA-SE alleles do not improve the predictive value of RF and ACPA for RA diagnosis in our cohort, and do not contribute to an earlier diagnosis in undifferentiated patients initially negative for RF and ACPA.

Associations between genetic factors, tobacco smoking and autoantibodies in familial and sporadic rheumatoid arthritis

OBJECTIVES

The objective of this study was to investigate the association between genes (HLA-DRB1 and PTPN22) and tobacco smoking, separately as well as combined, and serological markers of rheumatoid arthritis (RA) in a French population with RA.

METHODS

274 patients with RA with half of them belonging to RA multicase families, were genotyped for HLA-DRB1 allele and for PTPN22-1858 polymorphism. IgM rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP) antibodies were determined by ELISA method. The search for association relied on chi(2) test and odds ratio with 95% confidence interval calculation. The interaction study relied on the departure-from-additivity-based method.

RESULTS

The presence of at least one shared epitope (SE) allele was associated with anti-CCP antibodies presence (82.5% vs. 68.4%, p = 0.02), particularly with HLA-DRB1*0401 allele (28.0% vs. 16.4%, p = 0.01). Tobacco exposure was associated with anti-CCP antibodies, but only in presence of SE. A tendency toward an interaction was found between tobacco, the presence of at least one HLA-DRB1*0401 allele and anti-CCP antibodies (attributable proportion due to interaction = +0.24 (-0.21+0.76)). The cumulative dose of cigarette smoking was correlated with anti-CCP antibody titres (r = 0.19, p = 0.04). The presence of both SE and 1858T alleles was associated with a higher, but not significantly different, risk for anti-CCP antibodies presence than for each separately. No association was found between PTPN22-1858T allele and tobacco smoking for autoantibody positivity.

CONCLUSIONS

Our findings suggest an association between SE alleles and tobacco smoking for anti-CCP positivity and a tendency toward an interaction between the HLA-DRB1*0401 allele and smoking for anti-CCP positivity in this sample of RA.

Lack of association between the protein tyrosine phosphatase non-receptor 22 (PTPN22)*620W allele and systemic sclerosis in the French Caucasian population

The minor allele of the R620W missense single-nucleotide polymorphism (SNP; rs2476601) in the PTPN22 (protein tyrosine phosphatase non-receptor 22) gene has been reported to be associated with multiple autoimmune diseases, including type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis, juvenile idiopathic arthritis, autoimmune thyroiditis and vitiligo. Systemic sclerosis (SSc) is a connective tissue disease with some autoimmune abnormalities. The aim of our study was to test for association of the PTPN22*620W allele with SSc in a French Caucasian cohort with a case-control study of 121 patients with SSc and 103 controls. All patients and controls were genotyped for the PTPN22*R620W SNP. No association was found between the PTPN22*620W allele and SSc (7% v 9.2%, p = 0.39). The frequency of genotypes carrying at least one 620W allele was similar in both groups (13% v 17%, p = 0.38). The PTPN22*620W allele was also not associated with autoantibody patterns. Thus, the PTPN22*R620W polymorphism cannot be regarded as a genetic susceptibility factor for SSc in the French Caucasian population.

No association between tumour necrosis factor receptor type 2 gene polymorphism and rheumatoid arthritis severity: a comparison of the extremes of phenotypes

OBJECTIVES

To assess the association between the tumour necrosis factor receptor 2 (TNFR2) 196 M/R single-nucleotide polymorphism and rheumatoid arthritis (RA) severity by taking advantage of the extremes of phenotype that exist in arthritis.

METHODS

From the Leiden Early Arthritis Cohort (1700 patients), we selected patients who initially had the diagnosis of definite or probable RA according to the ACR criteria and developed complete remission (71 patients) or had the worst progression, to destructive disease (72 patients). A group of 135 healthy controls was included. The TNFR2 genotype was determined in these groups.

RESULTS

The extremes of phenotypes did not differ significantly in genotype distribution. No difference in genotype distribution between rheumatoid arthritis patients and healthy controls was observed.

CONCLUSION

Our study demonstrates that even by comparing the extremes of phenotypes no association between the TNFR2 genotype and disease severity can be detected in Caucasian patients with sporadic RA.

European genetic study on rheumatoid arthritis: is there a linkage of the interleukin-1 (IL-1), IL-10 or IL-4 genes to RA?

The genetic predisposition for rheumatoid arthritis (RA) is only partly explained by the HLA locus and most genetic factors involved in the susceptibility (and/or severity) of the disease await further identification. The first European genome scan in RA families provided suggestive evidence for linkage with a region (3.1/3q13) on chromosome 3, but many other potential RA susceptibility genes have yet to be analysed.

AIMS

To perform a linkage analysis with microsatellite markers located in the vicinity of the interleukin-1 (IL-1) gene superfamily, the IL-10 gene and the IL-4 gene cluster which might be considered putative candidate loci for RA.

METHODS

107 Caucasoid European RA sibpairs from 90 nuclear families were genotyped for markers flanking the genes for the IL-1 superfamily, IL-10 and the IL-4 gene cluster. Linkage analysis based on the identity by descent (IBD) in affected siblings was analysed with the program SIBPALNA. Affected sibpairs were stratified according to the identity by state (IBS) for three markers in the HLA region (DRB1 oligotyping, D6S276 and TNFa microsatellites) and to the presence/absence of erosive disease on X-ray examination.

RESULTS

Analysis of the whole family set showed an excess of allele sharing for markers of the IL-1 gene cluster (IBD 60%; P = 0.012) but not for IL-10 or IL-4. After stratification, the evidence of linkage to IL-1 was restricted to HLA concordant sibpairs (n = 32; IBD 70%; P = 0.006). Some evidence of linkage to IL-10 was also observed in HLA concordant sibpairs (IBD 66%; P = 0.03) and in sibpairs with erosive disease (n = 61; IBD 62%; P = 0.02).

CONCLUSIONS

We found suggestive evidence of linkage of RA to the IL-1 locus. The increased linkage to IL-1 and IL-10 in HLA-identical sibs suggests a possible interaction between these cytokines and the HLA loci. Moreover IL-10 could interact with HLA factors in predisposing to erosive disease. These results need to be tested in additional families for consistency and replication.

Clinical and immunogenetic characteristics of European multicase rheumatoid arthritis families

OBJECTIVE

To describe the characteristics of a new set of European families with affected sib pairs (ASP) collected by the European Consortium on Rheumatoid Arthritis Families (ECRAF) to replicate the results of our first genome scan. Potential gradients for disease severity in Europe and concordance within families were studied.

PATIENTS AND METHODS

From 1996 to 1998 European white families with at least two affected siblings were enrolled in the study. Demographic (sex, age at onset), clinical data (rheumatoid factor (RF), disease duration, erosive disease, extra-articular features (EF)), and HLA-DRB1 oligotyping were analysed.

RESULTS

565 patients with rheumatoid arthritis (RA), belonging to 271 families including 319 affected sib pairs (ASP) were collected. Belgium, France, Italy, the Netherlands, Portugal, and Spain contributed 20, 96, 52, 24, 9, and 70 families, respectively. Sex (78% women), age at onset (mean 44 years), and RF positivity (79%) were similar among the countries. Differences were found in disease duration (11-18 years) and in the prevalence of erosive disease (70-93%), nodules (15-44%), subjective Sjögren's syndrome (5-38%), and EF (3-16%) (p<0.05 in all cases). A total of 22% RA sibs were shared epitope (SE) negative, whereas 47% and 30% carried one and two SE alleles respectively. Carriage of SE differed widely among countries (p<0.0001): no SE alleles (6-36%), one allele (43-60%), and two alleles (20-39%). SE encoding alleles were mainly DRB1*04 in the Netherlands and Belgium, whereas SE carriage was less common and evenly distributed between DRB1*01, *04, and *10 in Mediterranean countries. No concordance within families was found either in age/calendar year of onset (intraclass correlation coefficient <0.50) or in clinical and radiological features (kappa<0.22).

CONCLUSIONS

The differences in RA characteristics between European countries and within families underline the heterogeneity of the disease. No clear cut gradient of disease severity was seen in Europe.

Noninherited maternal antigens do not increase the susceptibility for familial rheumatoid arthritis. European Consortium on Rheumatoid Arthritis Families (ECRAF)

OBJECTIVE

It has been proposed that noninherited maternal HLA-DR antigens (NIMA) might play a role in the susceptibility for rheumatoid arthritis (RA). This hypothesis has not been thoroughly tested in patients with familial RA, in whom genetic factors, either inherited or not, might have stronger influence than in patients with sporadic RA. We investigated the NIMA hypothesis in a large cohort of European patients with familial RA.

METHODS

The distribution of NIMA, noninherited paternal antigens (NIPA), and inherited HLA-DR antigens was assessed in patients with familial RA from all family sets collected from 1996 onwards by the ECRAF. HLA-DRB1 oligotyping from patients and all available nonaffected siblings and parents was carried out. Familial RA was defined by the presence of at least 2 affected first-degree relatives in the same family. The frequencies of HLA-DR NIMA and NIPA were compared using odds ratios after stratification for HLA-DR*04, *0401, and/or *0404 and shared epitope (SE) status. NIMA/NIPA that coincided with inherited parental HLA-DR antigens were considered redundant and were excluded from analysis.

RESULTS

NIMA and NIPA could be analyzed in 165 RA patients with familial RA and 84 nonaffected siblings. Patients were predominantly female, rheumatoid factor positive, and had erosive disease (81, 75, and 84%, respectively). Possession of HLA-DR*04 and *0401/*0404 alleles tended be more frequent in patients than in nonaffected siblings but this did not reach statistical significance. SE possession was similar in patients and healthy siblings, although the former had a double dose SE more often (37.6 vs 17.8%; p = 0.002). Transmission of SE encoding alleles from parents to offspring was skewed only in patients [OR (95% CI) 3.56 (2.55-4.95) vs 1.16 (0.75-1.79) in nonaffected siblings]. Using the NIPA as control, the frequencies of HLA-DRB1*04, *0401/*0404, and SE positive NIMA were not increased in patients lacking these susceptibility alleles. The frequencies of NIMA encoding susceptibility alleles in DR*04 and *0401/*0404 negative patients were lower than in nonaffected siblings.

CONCLUSION

Our results corroborate the association between RA and inherited SE alleles and do not support a role for noninherited HLA-DR maternal antigens in the susceptibility for familial RA.

Noninherited maternal antigens do not play a role in rheumatoid arthritis susceptibility in Europe. European Consortium on Rheumatoid Arthritis Families

OBJECTIVE

It has been proposed that noninherited maternal antigens (NIMA) (HLA-DR antigens) might play a role in susceptibility to rheumatoid arthritis (RA), especially in patients who are not genetically predisposed, such as those who are HLA-DR4 and/or shared epitope (SE) negative. The present study was undertaken to test the NIMA hypothesis in a large cohort of European RA patients assembled by the European Consortium on RA Families (ECRAF).

METHODS

HLA-DRB1 oligotyping was performed in families of European RA patients for whom both parents were alive. These families were consecutively recruited by the ECRAF between 1996 and 1998, for association studies. The frequencies of HLA-DR NIMA were compared with those of the noninherited paternal antigens (NIPA) after stratification for HLA-DR*04, *0401 and/or *0404, and SE status. NIMA or NIPA that coincided with inherited HLA-DR antigens were considered redundant and excluded from analysis. Calculations concerning the whole group and restricted to patients lacking parental RA were performed.

RESULTS

One hundred seventy families from France (n = 81), Belgium (n = 23), Spain (n = 24), Italy (n = 19), Portugal (n = 14), and The Netherlands (n = 9) were oligotyped. The group of probands was predominantly female (88%), positive for rheumatoid factor, DR*04, and SE (71%, 58%, and 75%, respectively), and had erosive disease (75%). Parental RA was reported in 21 families. Using the NIPA as control, the frequency of HLA-DRB1*04, *0401 and/or *0404-, or SE-positive NIMA was not found to be increased in patients lacking these susceptibility alleles. The same was true when the 21 probands with parental RA were excluded from analysis. In DRB1*04-positive patients, we found no evidence of a relevant effect of HLA-DR3 or DR6 in the NIMA.

CONCLUSION

Our results do not support the notion that noninherited maternal antigens have a role in susceptibility to RA in the offspring.

New susceptibility locus for rheumatoid arthritis suggested by a genome-wide linkage study

Rheumatoid arthritis (RA), the most common autoimmune disease, is associated in families with other autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM). Its genetic component has been suggested by familial aggregation (lambdas = 5), twin studies, and segregation analysis. HLA, which is the only susceptibility locus known, has been estimated to account for one-third of this component. The aim of this paper was to identify new RA loci. A genome scan was performed with 114 European Caucasian RA sib pairs from 97 nuclear families. Linkage was significant only for HLA (P < 2.5.10(-5)) and nominal for 19 markers in 14 other regions (P < 0.05). Four of the loci implicated in IDDM potentially overlap with these regions: the putative IDDM6, IDDM9, IDDM13, and DXS998 loci. The first two of these candidate regions, defined in the RA genome scan by the markers D18S68-D18S61-D18S469 (18q22-23) and D3S1267 (3q13), respectively, were studied in 194 additional RA sib pairs from 164 nuclear families. Support for linkage to chromosome 3 only was extended significantly (P = 0.002). The analysis of all 261 families provided a linkage evidence of P = 0. 001 and suggested an interaction between this putative RA locus and HLA. This locus could account for 16% of the genetic component of RA. Candidate genes include those coding for CD80 and CD86, molecules involved in antigen-specific T cell recognition. In conclusion, this first genome scan in RA Caucasian families revealed 14 candidate regions, one of which was supported further by the study of a second set of families.

A chromosome 14q11/TCR alpha/delta specific yeast artificial chromosome improves the detection rate and characterization of chromosome abnormalities in T-lymphoproliferative disorders

The rate of detection of chromosome abnormalities in T-cell proliferations is lower than that observed in B-cell malignancies. The former frequently involve the TCR alpha/delta locus at chromosome band 14q11. We have identified a YAC encompassing 70% of the TCR alpha/delta locus, which has been used as a fluorescence in situ hybridization probe to detect chromosome rearrangements involving 14q11, both at metaphase and within interphase nuclei, in patients with a variety of T-lymphoproliferative disorders. Its use allowed detection of previously unsuspected TCR alpha/delta rearrangements in 4/13 (30%) immature T-lineage acute leukemias, including two t(10;14) and 2 minor inversion 14s. It also clarified interpretation of complex chromosome 14 abnormalities in mature T-cell proliferations (T-prolymphocytic leukemia and ataxia telangiectasia). Use of this probe will aid the detection and characterization of abnormalities involving the TCR alpha/delta locus, particularly in cases with normal or complex karyotypes and in those proliferations for which mitoses are difficult to obtain.

Association of rheumatoid arthritis with an amino acid allelic variation of the T cell receptor

OBJECTIVE

To investigate allelic variations of T cell receptor residues for a contribution to rheumatoid arthritis (RA) susceptibility.

METHODS

We conducted an RA case-control study involving 1,579 northwest Europeans: 766 patients with erosive and rheumatoid factor-positive disease and 813 control subjects. Productive changes of segments TCRAV6S1, TCRAV7S1, TCRAV8S1, TCRAV10S2, and TCRBV6S1, TCRBV6S7 were investigated by single-strand conformation polymorphisms. The TCRAV8S1 association was confirmed by restriction fragment length polymorphism.

RESULTS

In the systematic study (77 patients and 119 controls), an increase in 1 TCRAV8S1 genotype was found in the RA patients (P = 0.0004). This finding was replicated in 2 further populations, one from France (212 patients and 254 controls) and the other from Britain (477 patients and 440 controls), with a similar odds ratio (OR), which allowed pooling of the data and confirmation of the association (OR 1.3 [95% confidence interval 1.1-1.7], P = 0.008).

CONCLUSION

These findings show evidence that TCRA is an RA susceptibility locus.

Acute leukaemia in paroxysmal nocturnal haemoglobinuria. Case report and review of the literature

Paroxysmal nocturnal haemoglobinuria (PNH) terminating in acute leukaemia (AL) is an infrequent condition. In several cases, flow cytometric analysis of glycosylphosphatidylinositol anchored membrane proteins such as DAF and CD59/MACIF has suggested the leukaemic cells to be derived from the PNH clone, thereby implicating PNH as a potential preleukaemic disease. In the present paper, we review the data for one patient treated in our hospital and 20 cases reported in the literature from 1969 to 1993. The sex ratio is 1 female/2 males, mean age at diagnosis of PNH was 46 years and the mean interval between the diagnoses of PNH and AL was 53 months. AL type was AML M6 in 8 patients, other types of AML in 12 and ALL in one, with a mean survival of 7.1 months following diagnosis of AL. In all cases analyzed, the PNH phenotype of erythrocytes disappeared with progression of AL, whereas reappearance of this phenotype with complete remission of AL was inconstant. PNH would thus appear to be a potential preleukemic disease. When this disorder terminates in AL, the type is often AML M6, although ALL is also possible. The prognosis of AL in PNH is poor as for other secondary leukaemias. Apart from marrow aplasia, leukaemic transformation is another life threatening complication of PNH which may justify allogeneic bone marrow transplantation (allo-BMT) and potential leukaemic transformation can therefore be an additional argument in favour of allo-BMT when pancytopenia develops in PNH patients.

HLA class I associations of ankylosing spondylitis in the white population in the United Kingdom

OBJECTIVE

To investigate the HLA class I associations of ankylosing spondylitis (AS) in the white population, with particular reference to HLA-B27 subtypes.

METHODS

HLA-B27 and -B60 typing was performed in 284 white patients with AS. Allele frequencies of HLA-B27 and HLA-B60 from 5926 white bone marrow donors were used for comparison. HLA-B27 subtyping was performed by single strand conformation polymorphism (SSCP) in all HLA-B27 positive AS patients, and 154 HLA-B27 positive ethnically matched blood donors.

RESULTS

The strong association of HLA-B27 and AS was confirmed (odds ratio (OR) 171, 95% confidence interval (CI) 135 to 218; p < 10(-99)). The association of HLA-B60 with AS was confirmed in HLA-B27 positive cases (OR 3.6, 95% CI 2.1 to 6.3; p < 5 x 10(-5)), and a similar association was demonstrated in HLA-B27 negative AS (OR 3.5, 95% CI 1.1 to 11.4; p < 0.05). No significant difference was observed in the frequencies of HLA-B27 allelic subtypes in patients and controls (HLA-B*2702, three of 172 patients v five of 154 controls; HLA-B*2705, 169 of 172 patients v 147 of 154 controls; HLA-B*2708, none of 172 patients v two of 154 controls), and no novel HLA-B27 alleles were detected.

CONCLUSION

HLA-B27 and -B60 are associated with susceptibility to AS, but differences in HLA-B27 subtype do not affect susceptibility to AS in this white population.

Genetic linkage of T-cell receptor alpha/delta complex to specific IgE responses

IgE responses to inhaled proteins underlie the clinical syndrome of allergic (atopic) asthma and rhinitis. We have investigated genetic linkage between specific IgE reactions to highly purified major allergens and the T-cell receptor (TCR) alpha and beta gene complexes on chromosome 14 and 7, respectively. Antigens tested included highly purified proteins from the housedust mite Dermatophagoides pteronyssinus, the domestic cat and dog, grass pollen, and the mould Alternaria alternata. Affected sibling-pair methods were used in two independent sets of families, one in the UK and one in Australia. No linkage of IgE serotypes to TCR-beta was detected, but significant linkage to TCR-alpha was seen in both family groups. For several of the IgE phenotypes investigated (positive responses to whole allergen sources or purified antigens or serum IgE above the 70th percentile in the population) the affected sibling-pairs showed significant sharing of TCR-alpha microsatellite alleles from both parents. The results show that a gene (or genes) in the TCR-alpha region modifies specific IgE responses.

Analysis of a T-cell receptor V beta segment implicated in susceptibility to rheumatoid arthritis: V beta 2 germline polymorphism does not encode susceptibility

OBJECTIVES

The assessment of allelic polymorphism of the T cell receptor gene segment, TCRBV2S1, in rheumatoid arthritis.

METHODS

A total of 136 patients with rheumatoid arthritis (RA) (ACR criteria) and 150 controls were TCRBV2S1 genotyped using a nested PCR amplification strategy followed by single-strand conformation polymorphism (SSCP) analysis.

RESULTS

The SSCP typing method detected two previously unknown alleles of the TCRBV2S1 gene segment. The TCRBV2S1 allele, genotype and inferred phenotype frequencies were similar in the RA patients and controls. No differences were apparent after the RA patients had been partitioned according to their HLA-DR genotypes.

CONCLUSIONS

SSCP analysis is a rapid and efficient method of typing T cell receptor germline polymorphisms. Allelic polymorphism of the T cell receptor variable segment, TCRBV2S1, does not influence susceptibility to RA.

Systematic study of human alpha beta T cell receptor V segments shows allelic variations resulting in a large number of distinct T cell receptor haplotypes

The variation of the alpha beta T cell receptor (TCR) results mainly from rearrangements of germ-line V, D and J elements combined with the processes of N- and P-region addition. In addition to this extensive diversity, diallelic polymorphism is also recognized in V regions of beta loci. Four such polymorphisms have previously been defined, but the full extent of such variation has not yet been established. To investigate allelic polymorphism, we used a strategy based V locus-specific polymerase chain reaction and single-strand conformation polymorphisms. Studying the two V beta 2 loci and the V alpha 8.1 locus, we found that all exhibited a coding polymorphism. One of the V beta 2 loci proved to be the first multiallele segment to be recognized, with three common variants. The second V beta 2 locus, for which none of the two alleles has been identified in cDNA, appeared in fact to be a V beta orphon, in abnormal location on the chromosome 9. A yeast artificial chromosome containing part of the TCRB locus allowed us to place the first V beta 2 segment on the known map to define haplotypes with two other polymorphic segments: V beta 1 and V beta 6.7. Multiple distinct haplotypes result from combinations between these polymorphic loci, showing that V beta regions are highly variable between individuals. Two alleles exist at the V alpha 8.1 segment and both are expressed. This represents the first example of a frequent coding polymorphism for TCRA gene. The distribution of allele frequencies for these segments suggest the action of balancing selection. These data add a further dimension to TCR polymorphism and suggest new candidates to explore TCR-encoded susceptibility to autoimmune diseases.

Exclusion of linkage between hypokalemic periodic paralysis (HOKPP) and three candidate loci

Hypokalemic periodic paralysis (HOKPP) is an autosomal dominant neuromuscular disorder characterized by flaccid paralysis accompanied by lowered serum potassium levels. We have tested polymorphic markers linked to the adult skeletal muscle sodium channel (SCN4A) locus at 17q23-q25, the T-cell receptor beta (TCRB) locus at 7q35, and the H-Ras cellular proton-cogene locus (HRAS) at 11p15.5 for linkage with the affected phenotype in a single multigenerational pedigree. No evidence for genetic linkage to HOKPP was found at any of the candidate loci.