Hereditary hemochromatosis as a risk factor for joint replacement surgery

A Matched-Cohort Analysis of Outcomes in Patients with Hereditary Hemochromatosis After Anterior Cervical Discectomy and Fusion

BACKGROUND

Hereditary hemochromatosis (HH) is a common autosomal recessive disorder. This disease affects gut iron transport, leading to iron overload, which affects immune function, coagulation mechanics, and bone health. Within the spine, HH contributes to decreased bone mineral density and accelerated intervertebral disc degeneration. The purpose of this study was to discover the differences in the rates of common 90-day postoperative complications and 1-year and 2-year surgical outcomes in patients with and without HH after anterior cervical discectomy and fusion (ACDF).

METHODS

Using the PearlDiver database, patients with active diagnoses of HH before ACDF were matched to patients without HH using a 1:5 ratio on the basis of age, sex, body mass index, and comorbidities. Postoperative complications were assessed at 90 days, and 1-year and 2-year surgical outcomes were assessed. All outcomes and complications were analyzed using multivariate logistic regression with significance achieved at P < 0.05.

RESULTS

Patients with HH had significantly higher rates of 1-year and 2-year reoperation rates compared with patients without HH (29.19% vs. 3.94% and 37.1% vs. 5.93%, respectively; P < 0.001). The rates of 90-day postoperative complications significantly increased in patients with HH including dysphagia, pneumonia, cerebrovascular accident, deep vein thrombosis, acute kidney injury, urinary tract infection, hyponatremia, surgical site infection, iatrogenic deformity, emergency department visit, and hospital readmission.

CONCLUSIONS

Patients with HH undergoing ACDF showed increased 90-day postoperative complications and significantly increased rates of 1-year and 2-year reoperation compared with patients without HH. These findings suggest that iron overload may contribute to adverse outcomes in patients with HH undergoing 1-level and 2-level ACDF.

EASL Clinical Practice Guidelines on haemochromatosis

Haemochromatosis is characterised by elevated transferrin saturation (TSAT) and progressive iron loading that mainly affects the liver. Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications. In patients homozygous for p.Cys282Tyr in HFE, provisional iron overload based on serum iron parameters (TSAT >45% and ferritin >200 μg/L in females and TSAT >50% and ferritin >300 μg/L in males and postmenopausal women) is sufficient to diagnose haemochromatosis. In patients with high TSAT and elevated ferritin but other HFE genotypes, diagnosis requires the presence of hepatic iron overload on MRI or liver biopsy. The stage of liver fibrosis and other end-organ damage should be carefully assessed at diagnosis because they determine disease management. Patients with advanced fibrosis should be included in a screening programme for hepatocellular carcinoma. Treatment targets for phlebotomy are ferritin <50 μg/L during the induction phase and <100 μg/L during the maintenance phase.

The Impact of Trace Elements on Osteoarthritis

Osteoarthritis (OA) is a progressive degenerative disease characterized by cartilage degradation, synovial inflammation, subchondral sclerosis and osteophyte formation. It has a multifactorial etiology with potential contributions from heredity, endocrine function, abnormal mechanical load and nutrition. Of particular considerations are trace element status. Several trace elements, such as boron and magnesium are essential for normal development of the bone and joint in human. While cadmium correlates with the severity of OA. The present review focuses on the roles of trace elements (boron, cadmium, copper, iron, magnesium, manganese, selenium, zinc) in OA and explores the mechanisms by which they act.

Postoperative Complications in Patients With Hereditary Hemochromatosis Undergoing Total Joint Arthroplasty: A Matched Cohort Analysis

AIMS

The purpose of this study is to determine differences in the rates of 90-day postoperative complications and 2- and 5-year surgical outcomes between patients with and without hereditary hemochromatosis (HH) after total joint arthroplasty (TJA).

METHODS

Patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) from 2010 to 2018 were identified in a national database (PearlDiver Technologies) using Current Procedural Terminology and International Classification of Diseases-9/10 codes. Patients with a history of HH were identified within the THA and TKA cohorts and matched with non-HH patients based on age, sex, Charlson Comorbidity Index, smoking status, and obesity (body mass index > 30). Ninety-day medical complications assessed included renal failure, arrhythmia, bleeding complications, blood transfusion, pneumonia, stroke, deep vein thrombosis, liver failure, heart failure, pulmonary embolism, sepsis, surgical site infection, wound dehiscence, readmission rate, and death. Two- and 5-year surgical complications assessed included all-cause revision, prosthetic joint infection, implant loosening, joint stiffness, and manipulation under anesthesia. All complications were analyzed using bivariate analysis and logistic regression, with significance set at P < 0.05.

RESULTS

Compared with non-HH patients, patients with HH had higher rates of stiffness at 2 and 5 years after THA (all, P < 0.001), as well as higher rates of aseptic loosening at 5 years after TKA (P = 0.036). However, patients with HH undergoing THA and TKA had no notable difference in 90-day postoperative complications when compared with non-HH patients.

DISCUSSION

Compared with non-HH patients, patients with HH undergoing TJA were shown to have worse 2- and 5-year surgical outcomes, without any increased risk of 90-day medical complications. These findings may be useful for surgical decision making for patients with HH undergoing TJA.

CLINICAL RELEVANCE

This study addresses a paucity in the current literature concerning the complication profile in HH patients with destructive joint arthropathy undergoing joint arthroplasty surgery.

Screening for hereditary haemochromatosis in patients undergoing knee arthroplasty : a retrospective cohort study of 2,035 patients

AIMS

Hereditary haemochromatosis is a genetic disorder that is caused by several known mutations in the human homeostatic iron regulator protein (HFE) gene. Abnormal accumulation of iron causes a joint disease that resembles osteoarthritis (OA), but appears at a relatively younger age and is accompanied by cirrhosis, diabetes, and injury to other organs. Increased serum transferrin saturation and ferritin levels are known markers of haemochromatosis with high positive predictive values.

METHODS

We have retrospectively analyzed the iron studies of a cohort of 2,035 patients undergoing knee joint arthroplasty due to OA.

RESULTS

No patients had HFE gene C282Y, S65C, or H63D mutations testing. In total, 18 patients (2.96%) of the male cohort and 51 (3.58%) of the female cohort had pathologically increased ferritin levels that may be indicative of haemochromatosis. Seven patients (0.34%) had serum transferrin saturation above 45%.

CONCLUSION

The awareness for the diagnosis of this disorder in Orthopaedics is low and needs improvement. Osteoarthritic patients undergoing knee arthroplasty should be routinely screened for haemochromatosis by iron studies and referred to genetic testing when needed. Level of evidence: Level III - Retrospective cohort study. Cite this article: Bone Jt Open 2021;2(12):1062-1066.

Survival and development of health conditions after iron depletion therapy in C282Y-linked hemochromatosis patients

BACKGROUND

We report long-term survival and development of selected health conditions in Ontario-based referred and screened C282Y homozygotes for hemochromatosis treated by phlebotomy compared with an untreated control group known to be without HFE mutations.

METHODS

Patient characteristics and outcomes (all-cause mortality, liver cancer, diabetes, cirrhosis, hip or knee joint replacement, and osteoarthritis) were ascertained using a linked health administrative database held at ICES. Outcomes were assessed between groups without the outcome at baseline using Cox proportional hazards regression adjusted for age and sex. All C282Y homozygotes with elevated serum ferritin were treated by phlebotomy to reach serum ferritin of 50 µg/L. Our cohort included 527 C282Y homozygotes (311 men, 216 women, mean age 48 years) and 12,879 control participants (5,667 men and 7,212 women).

RESULTS

C282Y homozygotes had an increased risk of all-cause mortality (aHR 1.44 [1.19-1.75], p <0.001); hepatocellular carcinoma (aHR 8.30 [3.97-17.34], p <0.001); hip or knee joint replacement (aHR 3.06 [2.46-3.81], p <0.001); osteoarthritis (aHR 1.72 [1.47-2.01], p <0.001); and cirrhosis (aHR 3.87 [3.05-4.92], p <0.001). C282Y homozygotes did not have an increased risk for diagnosis of diabetes) (aHR 0.84 [0.67-1.07], p = 0.16) during follow-up (median 17.7 y).

CONCLUSIONS

C282Y homozygotes experience higher death and complication rates than individuals without HFE mutations, despite treatment by phlebotomy. Diabetes did not increase after phlebotomy therapy.

Increased rates of spinal fusion surgery in patients with hereditary hemochromatosis: a five-year propensity matched cohort analysis

OBJECT

Spinal arthropathy is associated with hereditary hemochromatosis and has been linked to calcium pyrophosphate dehydrate crystal deposition (CPPD) which resembles ankylosing spondylitis on radiograph, yet lacks clinical findings of inflammatory spinal arthritis. The aim of our study was to assess the use of spinal surgery and its outcomes in the US inpatient population with hereditary hemochromatosis from 2012 to 2016 by using the US Nationwide Inpatient Sample (NIS) database.

METHODS

The observational retrospective cohort study uses the NIS 2012 to 2016. All patients with hereditary hemochromatosis were included using International Classification of Diseases 9th and 10th revisions, Clinical Modification codes. The cohort was stratified according to having undergone spinal surgery and substratified by the type of surgery. The primary outcome was determining the use of spinal surgery in patients with hereditary hemochromatosis. Secondary outcomes were determining length of hospital stay and total hospital charges and costs.

RESULTS

A total of 39 780 patients with hereditary hemochromatosis were identified and propensity matched to nonhereditary hemochromatosis controls. The mean patient age was 61 years, and 65% were females. For the primary outcome patients with hereditary hemochromatosis underwent significantly more spinal fusion surgery compared to patients without hereditary hemochromatosis odds of 2.13 (P = 0.05). While there was no difference in mean LOS, or costs, patients with hereditary hemochromatosis had higher hospital charges.

CONCLUSION

Hereditary hemochromatosis is associated with higher odds of spinal fusion. It is a major complication not improved by phlebotomy, and there are currently no therapies to prevent this joint disease.

Hereditary hemochromatosis and risk of joint replacement surgery: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

Arthritis is a known manifestation of hereditary hemochromatosis. However, whether patients with hereditary hemochromatosis have an increased risk of having joint replacement surgery compared to the general population is still unknown. This meta-analysis was conducted to better characterize this risk.

METHODS

A comprehensive literature review was conducted utilizing the MEDLINE and EMBASE databases through September 2019 to identify all cohort studies that compared prevalence or incidence of joint replacement surgery (hip, ankle, or knee) between patients with hereditary hemochromatosis and individuals without hereditary hemochromatosis. Effect estimates from each study were extracted and combined together using the random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

A total of five studies with 1 293 407 participants fulfilled the eligibility criteria and were included in the meta-analysis. Overall, the risk of having joint replacement surgery was significantly increased in patients with hereditary hemochromatosis compared to individuals without hereditary hemochromatosis with the pooled relative risk (RR) of 3.32 [95% confidence interval (CI), 1.60-6.86; I 88%]. Analysis by joint found a significantly increased risk of having hip and ankle replacement surgery among patients with hereditary hemochromatosis compared with the pooled RR of 2.62 (95% CI, 2.09-3.30; I 47%) and 8.94 (95% CI, 3.85-20.78; I 14%), respectively. The risk of having knee replacement surgery was also increased but was not statistically significant (pooled RR 1.57, 95% CI, 0.83-2.98; I 66%).

CONCLUSIONS

A significantly increased risk of needed joint replacement surgery among patients with hereditary hemochromatosis compared to patients without hereditary hemochromatosis was demonstrated in this study. Further studies are required to determine whether this association is causal.

Bone and joint complications in patients with hereditary hemochromatosis: a cross-sectional study of 93 patients

Background

The aim of this study was to determine the frequency and characteristics of bone and joint complications, specifically bone fragility, joint replacement surgery, and arthropathy, in hereditary hemochromatosis (HH) and related factors.

Methods

This study was a cross-sectional observational study of 93 patients with HH. Radiographs of the hands, wrists, knees, and ankles were scored for joint space narrowing, erosions and cysts, osteophytes, and chondrocalcinosis. Prevalent (vertebral and non-vertebral) fragility fractures were recorded and bone mineral density (BMD) was systematically evaluated by dual energy X-ray absorptiometry. Bone fragility was defined as (i) a T-score ⩽ -2.5 at any site with or without a prevalent fragility fracture, or (ii) a T-score between -1.0 and -2.5 at any site and a prevalent fragility fracture.

Results

The mean age of the patients was 60.0 (11.2) years, and 58.0% of them were men. The frequency of radiographic MCP2-3 arthropathy was 37.6% (95% CI 0.28-0.48). Radiographic MCP2-3 arthropathy was independently associated with older age [OR 1.17 (1.09-1.26) per year, p < 0.0001], male sex [OR 3.89 (1.17-12.97), p = 0.027] and C282Y+/+ genotype [OR 4.78 (1.46-15.68), p = 0.010]. The frequency of joint replacement surgery was 12.9% (95% CI 0.07-0.21). The frequency of bone fragility was 20.4% (95% CI 0.13-0.30). Bone fragility was independently associated with hepatic cirrhosis [OR 8.20 (1.74-38.68), p = 0.008].

Discussion

Radiographic MCP2-3 arthropathy was found to occur in 37.6% of patients with HH. The association observed between this form of arthropathy and C282Y homozygosity, male sex, and older age suggests that demographic characteristics and genetic background are likely to be major determinants of this joint disorder and play a more important role than severity of iron overload. Bone fragility was observed in a fifth of the patients with HH, independently of genetic background and severity of iron overload, and was strongly associated with hepatic cirrhosis.

Conclusion

Future investigations should focus on pathogenesis and early identification of patients at risk of developing bone and joint complications secondary to HH.

Inherited iron overload disorders

Hereditary iron overload includes several disorders characterized by iron accumulation in tissues, organs, or even single cells or subcellular compartments. They are determined by mutations in genes directly involved in hepcidin regulation, cellular iron uptake, management and export, iron transport and storage. Systemic forms are characterized by increased serum ferritin with or without high transferrin saturation, and with or without functional iron deficient anemia. Hemochromatosis includes five different genetic forms all characterized by high transferrin saturation and serum ferritin, but with different penetrance and expression. Mutations in HFE, HFE2, HAMP and TFR2 lead to inadequate or severely reduced hepcidin synthesis that, in turn, induces increased intestinal iron absorption and macrophage iron release leading to tissue iron overload. The severity of hepcidin down-regulation defines the severity of iron overload and clinical complications. Hemochromatosis type 4 is caused by dominant gain-of-function mutations of ferroportin preventing hepcidin-ferroportin binding and leading to hepcidin resistance. Ferroportin disease is due to loss-of-function mutation of SLC40A1 that impairs the iron export efficiency of ferroportin, causes iron retention in reticuloendothelial cell and hyperferritinemia with normal transferrin saturation. Aceruloplasminemia is caused by defective iron release from storage and lead to mild microcytic anemia, low serum iron, and iron retention in several organs including the brain, causing severe neurological manifestations. Atransferrinemia and DMT1 deficiency are characterized by iron deficient erythropoiesis, severe microcytic anemia with high transferrin saturation and parenchymal iron overload due to secondary hepcidin suppression. Diagnosis of the different forms of hereditary iron overload disorders involves a sequential strategy that combines clinical, imaging, biochemical, and genetic data. Management of iron overload relies on two main therapies: blood removal and iron chelators. Specific therapeutic options are indicated in patients with atransferrinemia, DMT1 deficiency and aceruloplasminemia.

Contemporary Total Hip and Total Knee Arthroplasty Results in Patients with Hemochromatosis

BACKGROUND

Hemochromatosis can result in metabolic bone pathology (due to excessive iron absorption) and degenerative joint disease, leading to total joint arthroplasties. The aim of this study is to analyze the survivorship, complications, radiographic results, and clinical outcomes of patients with hemochromatosis who received either a total hip arthroplasty (THA) or a total knee arthroplasty (TKA).

METHODS

We identified 34 lower extremity arthroplasties in 29 patients with hemochromatosis performed between 2000 and 2016. There were 17 primary THAs in 15 patients and 17 primary TKAs in 14 patients. Mean age at arthroplasty was 63 years with 76% being male. The mean body mass index was 28 kg/m². Mean follow-up was 5 years.

RESULTS

The survivorship free from any revision for THAs was 94% at 10 years. One patient was revised for aseptic loosening of the femoral stem at 6 months. In THA patients, no infections, no other complications, and no radiographic evidence of aseptic loosening were identified. Harris Hip Scores improved from a mean of 55 preoperatively to 94 postoperatively (P < .001). The survivorship free from any revision for TKAs was 100% at 10 years. Two patients (12%) developed acquired idiopathic stiffness postoperatively; no infections were identified. There was no radiographic evidence of aseptic loosening in any TKA. Knee Society Scores improved from a mean of 61 preoperatively to 94 postoperatively (P < .001).

CONCLUSION

This study found excellent survivorship, significant improvements in clinical outcomes, and a very low complication profile for both THA and TKA in patients with hemochromatosis.

Hereditary hemochromatosis is associated with increased use of joint replacement surgery: Results of a nationwide analysis

BACKGROUND

Hereditary hemochromatosis (HH) may lead to iron deposition-mediated arthropathy, causing progressive joint degeneration, necessitating replacement arthroplasty. Studies have noted an increased need for replacement arthroplasty in patients with HH. We aimed to compare the use of replacement arthroplasty and inpatient economic burden in patients with and without HH.

METHODS

For our retrospective cohort study, we used the 2014 Nationwide Inpatient Sample. Patients with an International Classification of Diseases, Ninth Revision code for HH were included. The primary outcome was use of replacement arthroplasty; secondary outcomes were hospital length of stay, hospital costs, and total hospitalization charges. Multivariate logistic regression yielded confounder-adjusted odds ratios (ORs) and means.

RESULTS

Of 18,250 patients with HH, 7,483 (41.0%) were women and 1,155 (6.3%) underwent replacement arthroplasty. Mean (SD) age for patients with HH and arthroplasty was 66 (18) years. The percentage of patients with HH who underwent replacement arthroplasty was higher than those without HH (3.4%; P<.01). On multivariate analysis, young-adult females and elderly patients with HH were more likely to undergo replacement arthroplasty compared to those without HH of the corresponding gender and age group. Mean length of stay, hospital costs, and total hospitalization charges were increased only in young adult females.

CONCLUSIONS

HH is associated with increased odds of replacement arthroplasty, particularly in the elderly, which can potentially suggest faster arthropathy progression in this age group and should raise awareness in clinicians taking care of patients with HH. Future research should identify factors mediating arthropathy progression in patients with HH.

[Chondrocalcinosis: idiopathic or manifestation of rare metabolic diseases?]

Calcification in hyaline and fibrocartilage is caused by the deposition of calcium pyrophosphate dehydrate, commonly referred to as chondrocalcinosis. Clinically, this can lead to arthritis symptoms similar to a gout attack -"pseudogout". Nonetheless, also chronic or asymptomatic disease courses are possible. The prevalence of chondrocalcinosis increases with age. The diagnostic workup of degenerative joint disease, therefore, often reveals calcifications of articular cartilage as harmless incidental findings. However, particularly in patients younger than 60 years of age, chondrocalcinosis can be the symptom of an underlying metabolic disease. This review article highlights these rare diseases and presents unusual manifestations of chondrocalcinosis.

HFE hemochromatosis screening in patients with severe hip osteoarthritis: A prospective cross-sectional study

OBJECTIVE

Despite the high frequency of HFE gene mutations in Western Europe, widespread screening for HFE hemochromatosis is not recommended due to its variable phenotype. Joint pain and a premature osteoarthritis-like disease including the hip joints are the most frequent manifestation in patients with HFE hemochromatosis and iron overload. Therefore, screening of patients with severe osteoarthritis of the hip could identify patients with HFE hemochromatosis.

METHODS

In this prospective cross-sectional study, 940 patients aged <70 years with end-stage osteoarthritis of the hip undergoing elective joint replacement surgery were screened for HFE hemochromatosis and compared to age- and sex-matched controls.

RESULTS

No greater prevalence of C282Y homozygosity mutation or elevated serum ferritin or transferrin saturation levels was found in the study cohort with severe osteoarthritis of the hip than in controls from the general population.

CONCLUSION

Our screening approach could not identify an increased prevalence of HFE gene mutations and iron overload in younger patients with severe osteoarthritis of the hip.

Ultrasound verified inflammation and structural damage in patients with hereditary haemochromatosis-related arthropathy

Background

Chronic arthropathy occurs in approximately two thirds of patients with hereditary haemochromatosis (HH). The aim was to study inflammatory and structural lesions in patients with HH with (HH-A) and without arthropathy (HH-WA) using ultrasonography.

Methods

This was a cross-sectional study of 26 patients with HH-A, 24 with HH-WA and 37 with hand osteoarthritis (HOA). Clinical examination was performed in 68 joints, and we retrieved data on hand function, pain and global disease activity (all using a visual analogue scale (VAS)), morning stiffness and ferritin levels. Standard x-ray and ultrasound were conducted in 36 joints (hands, hips, knees and ankles), and we graded grey scale synovitis (GSS), power Doppler ultrasound (PD), osteophytes, erosions, tenosynovitis and cartilage damage semi-quantitatively in accordance with prior publications.

Results

Ultrasound revealed a high proportion of inflammatory changes in HH-A; GSS was found in 96.2% and PD signals in 80.8% of patients (median GSS score 9, PD score 2.5). The frequency of these findings was similar in HOA. Inflammation was also common in HH-WA, yielding GSS in 83.3% and PD signals in 50.0% of patients. Cartilage damage was most prominent in HH-A as compared to HH-WA and HOA (median scores 11.0, 2.5 and 2.0, respectively). The prevalence and extent of erosions and osteophytes were similar in all groups. None of the ultrasound scores was associated with pain or function; GSS, PD, osteophyte and cartilage scores correlated with x-ray-verified structural damage.

Conclusion

A high prevalence of ultrasound-verified inflammation and cartilage damage was found in HH-A, and to a lesser extent in HH-WA. These findings were associated with x-ray-verified damage but not with clinical scores of pain and function.

Iron overload in a murine model of hereditary hemochromatosis is associated with accelerated progression of osteoarthritis under mechanical stress

OBJECTIVE

Hereditary hemochromatosis (HH) is a disease caused by mutations in the Hfe gene characterised by systemic iron overload and associated with an increased prevalence of osteoarthritis (OA) but the role of iron overload in the development of OA is still undefined. To further understand the molecular mechanisms involved we have used a murine model of HH and studied the progression of experimental OA under mechanical stress.

DESIGN

OA was surgically induced in the knee joints of 10-week-old C57BL6 (wild-type) mice and Hfe-KO mice. OA progression was assessed using histology, micro CT, gene expression and immunohistochemistry at 8 weeks after surgery.

RESULTS

Hfe-KO mice showed a systemic iron overload and an increased iron accumulation in the knee synovial membrane following surgery. The histological OA score was significantly higher in the Hfe-KO mice at 8 weeks after surgery. Micro CT study of the proximal tibia revealed increased subchondral bone volume and increased trabecular thickness. Gene expression and immunohistochemical analysis showed a significant increase in the expression of matrix metallopeptidase 3 (MMP-3) in the joints of Hfe-KO mice compared with control mice at 8 weeks after surgery.

CONCLUSIONS

HH was associated with an accelerated development of OA in mice. Our findings suggest that synovial iron overload has a definite role in the progression of HH-related OA.

Effect of C282Y genotype on self-reported musculoskeletal complications in hereditary hemochromatosis

OBJECTIVE

Arthropathy that mimics osteoarthritis (OA) and osteoporosis (OP) is considered a complication of hereditary hemochromatosis (HH). We have limited data comparing OA and OP prevalence among HH patients with different hemochromatosis type 1 (HFE) genotypes. We investigated the prevalence of OA and OP in patients with HH by C282Y homozygosity and compound heterozygosity (C282Y/H63D) genotype.

METHODS

A total of 306 patients with HH completed a questionnaire. Clinical and demographic characteristics and presence of OA, OP and related complications were compared by genotype, adjusting for age, sex, body mass index (BMI), current smoking and menopausal status.

RESULTS

In total, 266 of the 306 patients (87%) were homozygous for C282Y, and 40 (13%) were compound heterozygous. The 2 groups did not differ by median age [60 (interquartile range [IQR] 53 to 68) vs. 61 (55 to 67) years, P=0.8], sex (female: 48.8% vs. 37.5%, P=0.18) or current smoking habits (12.4% vs. 10%, P=0.3). As compared with compound heterozygous patients, C282Y homozygous patients had higher median serum ferritin concentration at diagnosis [1090 (IQR 610 to 2210) vs. 603 (362 to 950) µg/L, P<0.001], higher median transferrin saturation [80% (IQR 66 to 91%) vs. 63% (55 to 72%), P<0.001]) and lower median BMI [24.8 (22.1 to 26.9) vs. 26.2 (23.5 to 30.3) kg/m2, P<0.003]. The overall prevalence of self-reported OA was significantly higher with C282Y homozygosity than compound heterozygosity (53.4% vs. 32.5%; adjusted odds ratio [aOR] 2.4 [95% confidence interval 1.2-5.0]), as was self-reported OP (25.6% vs. 7.5%; aOR 3.5 [1.1-12.1]).

CONCLUSION

Patients with C282Y homozygosity may be at increased risk of musculoskeletal complications of HH.

HFE-related hemochromatosis: an update for the rheumatologist

Hereditary hemochromatosis is a frequent disease in Caucasian populations. It leads to progressive iron overload in a variety of organs. The most common cause is the C282Y homozygous mutation in the HFE gene. The classical triad of skin hyperpigmentation, diabetes, and liver cirrhosis is nowadays rare but musculoskeletal symptoms are common in HFE-related hemochromatosis. Typically the second and third metacarpophalangeal joints, and the wrist, hip, and ankle joints are affected. Clinical symptoms include osteoarthritis-like symptoms, pseudogout attacks, and synovitis sometimes resembling rheumatoid arthritis. Radiographs show degenerative changes with joint space narrowing, osteophytes, and subchondral cysts. Chondrocalcinosis in the wrist and knee joints is seen in up to 50 % of patients. Although most other organ manifestations regress during phlebotomy, musculoskeletal symptoms often persist or even become worse. Importantly, patients are at an increased risk of severe large-joint arthritis necessitating joint replacement surgery. Therefore, future research should focus on the pathogenesis and treatment options for HH arthropathy.

Molecular basis of HFE-hemochromatosis

Iron-overload disorders owing to genetic misregulation of iron acquisition are referred to as hereditary hemochromatosis (HH). The most prevalent genetic iron overload disorder in Caucasians is caused by mutations in the HFE gene, an atypical MHC class I molecule. Recent studies classified HFE/Hfe-HH as a liver disease with the primarily failure in the production of the liver iron hormone hepcidin in hepatocytes. Inadequate hepcidin expression signals for excessive iron absorption from the diet and iron deposition in tissues causing multiple organ damage and failure. This review focuses on the molecular actions of the HFE/Hfe and hepcidin in maintaining systemic iron homeostasis and approaches undertaken so far to combat iron overload in HFE/Hfe-HH. In the light of the recent investigations, novel roles of extra-hepatocytic Hfe are discussed raising a question to the relevance of the multipurpose functions of Hfe for the understanding of HH-associated pathologies.

Age-dependent ferritin elevations and HFE C282Y mutation as risk factors for symptomatic knee osteoarthritis in males: a longitudinal cohort study

Background

Age, gender and genetic predisposition are major intrinsic risk factors for osteoarthritis (OA). Iron increases are associated with age and gene mutation. In the present study, we examined whether serum ferritin, an indicator of total body iron stores, correlates with clinical features in patients with OA, and whether the hemochromatosis Fe (HFE) gene mutation plays a role.

Methods

In a 2-year longitudinal observational study, 127 patients with knee OA and 20 healthy individuals (controls) were enrolled. All patients underwent standardized weight-bearing fixed-flexion posteroanterior knee radiographs. Peripheral blood samples were analyzed for serum ferritin, and genotyped for HFE using allelic discrimination methods.

Results

Higher levels of serum ferritin were found in patients older than 56 years (P =0.0186) and males (P =0.0006), with a trend toward higher ferritin in patients with OA. HFE gene mutation carriers were more prevalent among patients with OA than among healthy controls. When stratified further by gender, we found that male patients with OA had higher levels of serum ferritin than male control subjects [odds ratio = 4.18 (limits of 95% confidence interval: 0.86–27.69, P = 0.048)]. Analyses of radiographic data indicated that higher ferritin was associated with narrower joint space width at baseline (P = 0.032) in male patients. Additionally, among men, risk prediction of radiographic severity [Kellgren-Lawrence (KL) grade >2)] in the higher ferritin group was almost five times that of the lower ferritin group (odds ratio = 4.74, P = 0.023).

Conclusion

Our data suggest that increased ferritin levels are associated with symptomatic knee OA in males. This finding needs to be validated in a larger cohort of patients.

Increased risk of arthropathies and joint replacement surgery in patients with genetic hemochromatosis: a study of 3,531 patients and their 11,794 first-degree relatives

OBJECTIVE

Genetic hemochromatosis (GH) is an autosomal recessive disease in individuals of Northern and Western European descent. Heterozygosity for the C282Y mutation is common (6-20%). Arthropathy is one of the few complications of GH suggested not to be associated with iron body stores; synovial iron deposition remains in iron-depleted patients. Previous studies suggest an elevated prevalence of clinical and radiographic signs of arthropathy in patients with GH, and 2 smaller studies suggest a possibly elevated risk of joint replacement surgery, but more mixed results are shown regarding risks with HFE genotype. We therefore assessed the risks of arthropathy and joint replacement surgery in patients with GH and in their first-degree relatives (FDRs).

METHODS

We performed a population-based cohort study of 3,531 patients with GH and of their 11,794 FDRs (assumed to be heterozygous for the C282Y mutation) using nationwide Swedish population-based health and census registers. Hazard ratios (HRs) of arthropathies and joint replacement surgeries among patients and their FDRs (versus the general population) were assessed using Cox regression.

RESULTS

Between 1997 and 2005, 406 of 3,531 patients were reported/hospitalized with any noninfectious arthropathies, including osteoarthritis, corresponding to an HR of 2.38 (95% confidence interval [95% CI] 2.14-2.64). Patients were also at increased risk of hip replacement (HR 2.77, 95% CI 2.27-3.38) and knee replacement (HR 2.14, 95% CI 1.58-2.88) surgery. Among the 11,794 FDRs (patients excluded), we found no increased risk of any of the joint morbidities.

CONCLUSION

Patients with GH, but not their FDRs, are at increased risk of arthropathies, including the need for joint replacement surgery.

VCAM-1 serum levels are associated with arthropathy in hereditary haemochromatosis

OBJECTIVES

The aim of this study was to assess the role of vascular adhesion molecule 1 (VCAM-1) in patients with hereditary haemochromatosis (HH) with or without arthropathy.

METHODS

Sera from a large cross-sectional cohort of unselected HH patients (n=147) were obtained and compared to an age-matched and sex-matched control group. Serum levels of VCAM-1 were measured by ELISA and were correlated with clinical measures.

RESULTS

VCAM-1 serum levels were elevated in HH patients as compared to matched controls (mean 913±456 vs 654±451 ng/ml, p<0.0001). Within the HH patient group, VCAM-1 levels were much higher in patients with arthropathy and joint replacement surgery. VCAM-1 levels correlated well with radiographic measures of HH arthropathy (r=0.36, p<0.0001). Multivariate regression analysis confirmed a highly significant association of VCAM-1 serum levels and the presence of HH arthropathy, independent from diabetes, body mass index and age.

CONCLUSIONS

VCAM-1 serum levels emerge as a biomarker for haemochromatosis arthropathy.

Review article: the iron overload syndromes

BACKGROUND

Iron overload syndromes encompass a wide range of hereditary and acquired conditions. Major developments in the field of genetics and the discovery of hepcidin as a central regulator of iron homeostasis have greatly increased our understanding of the pathophysiology of iron overload syndromes.

AIM

To review advances in iron regulation and iron overload syndrome with special emphasis on hereditary haemochromatosis, the prototype iron overload syndrome.

METHODS

A PubMed search using words such as 'iron overload', 'hemochromatosis', 'HFE', 'Non-HFE', 'secondary iron overload' was undertaken.

RESULTS

Iron overload is associated with significant morbidity and mortality. Sensitive diagnostic tests and effective therapy are widely available and can prevent complications associated with iron accumulation in end- organs. Therapeutic phlebotomy remains the cornerstone of therapy for removal of excess body iron, but novel therapeutic agents including oral iron chelators have been developed for iron overload associated with anaemia.

CONCLUSIONS

Iron overload disorders are common. Inexpensive screening tests as well as confirmatory diagnostic tests are widely available. Increased awareness of the causes and importance of early diagnosis and knowledge of the appropriate use of genetic testing are encouraged. The availability of novel treatments should increase therapeutic options for patients with iron overload disorders.

Rheumatologic manifestations of benign and malignant haematological disorders

Diseases of blood and lymphoreticular system can have multisystem manifestations. Rheumatologic involvement has been reported in association with many benign and malignant haematological disorders; these patients are equally likely to present to both clinical rheumatologists and haematologists. This review focuses on the well-described rheumatologic features, other occasionally reported rheumatologic manifestations and unusual musculoskeletal complications related to the treatment in patients with underlying haematological conditions. The aim of this review is to help increase the awareness of rheumatologic manifestations seen in the blood disorders and to highlight the potential diagnostic pitfalls.