Acquired chondronecrosis

Decreased Expression of CHST-12, CHST-13, and UST in the Proximal Interphalangeal Joint Cartilage of School-Age Children with Kashin-Beck Disease: an Endemic Osteoarthritis in China Caused by Selenium Deficiency

The objective of this study is to investigate changes in the expression of enzymes involved in chondroitin sulfate (CS) sulfation in distal articular surface of proximal interphalangeal joint isolated from school-age children patients with Kashin-Beck disease (KBD), using normal children as controls. Articular cartilage samples were collected from four normal and four KBD children (7-12 years old), and these children were assigned to control and KBD groups. Hematoxylin and eosin (H&E), toluidine blue (TB), and immunohistochemical (IHC) stainings were utilized to evaluate changes in joint pathology and expression of enzymes involved in CS sulfation, including carbohydrate sulfotransferase 12 (CHST-12), carbohydrate sulfotransferase 13 (CHST-13), and uronyl 2-O-sulfotransferase (UST). The correspondence results were examined by semi-quantitative analysis. Compared with the control group, the KBD group showed the following: a significant decrease of total chondrocytes in superficial, middle, and deep layers and deposition of sulfated glycosaminoglycans in extracellular matrix of KBD cartilage were observed; positive staining chondrocytes of CHST-12, CHST-13, and UST were significantly less in superficial zone of KBD cartilage; and CHST-13 positive staining chondrocytes was reduced in deep zone of KBD cartilage. In contrast, the positive staining rates of CHST-12, CHST-13, and UST in KBD were significantly higher than those in the control group. The decreased expression of these enzymes and the physiologic compensatory reaction may be the signs of early-stage KBD. The alterations of CS structure modifying sulfotransferases in finger articular cartilage might play an important role in the onset and pathogenesis of school-age KBD children.

Conservative tibiotalocalcaneal fusion for partial talar avascular necrosis in conjunction with ankle and subtalar joint osteoarthritis in Kashin-Beck disease: A case report

RATIONALE

Kashin-Beck disease (KBD) is known for some typical characters like finger joint enlargement, shortened fingers, and dwarfism. However, Avascular necrosis (AVN) of the talus in KBD has rarely been reported in the literature. Here, we reported on a KBD patient presented with partial AVN of the talus in conjunction with ankle and subtalar arthritis.

PATIENT CONCERNS

A 50-year-old woman presented with severe pain and limited range of motion in her left ankle and subtalar joint while walking for 2 years. She had been walking with the aid of crutches for many years. Conservative treatment with rigid orthosis and activity restriction could not help reduce the pain in the left foot.

DIAGNOSES

Radiographs demonstrated that partial AVN was developed in the body of the talus and arthritis was viewed in the left ankle and subtalar joint. Hence, we established the diagnosis of partial talar AVN in conjunction with ankle and subtalar arthritis.

INTERVENTIONS

A conservative tibiotalocalcaneal fusion attempting to preserve as much viable talar body as possible was performed using a humeral locking plate and 2 cannulated compression screws.

OUTCOMES

Bone union proved by CT scan and a good alignment of the left limb were achieved at 4-month follow-up postoperatively.

LESSONS

Partial AVN of the talus along with ankle and subtalar arthritis in KBD patients has rarely been reported as it is not a common characteristic of KBD in clinical practice. Conservative tibiotalocalcaneal fusion could help preserving much more viable talar body, maintaining most structural integrity of the ankle joint, and achieving a stable and plantigrade foot postoperatively.

Selenium, Selenoproteins, and Immunity

Selenium is an essential micronutrient that plays a crucial role in development and a wide variety of physiological processes including effect immune responses. The immune system relies on adequate dietary selenium intake and this nutrient exerts its biological effects mostly through its incorporation into selenoproteins. The selenoproteome contains 25 members in humans that exhibit a wide variety of functions. The development of high-throughput omic approaches and novel bioinformatics tools has led to new insights regarding the effects of selenium and selenoproteins in human immuno-biology. Equally important are the innovative experimental systems that have emerged to interrogate molecular mechanisms underlying those effects. This review presents a summary of the current understanding of the role of selenium and selenoproteins in regulating immune cell functions and how dysregulation of these processes may lead to inflammation or immune-related diseases.

The arthropathic and functional impairment features of adult Kashin-Beck disease patients in Aba Tibetan area in China

OBJECT

The purpose of the study was to analyze the features of arthropathic changes and functional impairments as well as the correlations between them for adult patients suffered with Kashin-Beck disease (KBD) in Aba Tibetan area of Sichuan Province, China.

METHOD

Nine hundred and eighty-nine adult KBD patients in Aba KBD prevalence area were investigated. The arthropathic changes including arthritic pain (evaluated by visual analog pain score (VAS)), deformity, limited range of joint motion (ROM), as well as daily living and working function were examined, evaluated and analyzed.

RESULTS

Ninety-two percent of patients suffered with multiple affected joints in both upper and lower extremities. The most frequently affected joints were knee (86.1%) and hand (77.2%). The most painful joints were knee (VAS 7.1 ± 1.9) and elbow (VAS 6.8 ± 2.1). Joint deformities most frequently represented as enlargement of interphalangeal joints (93.2%). Limitation of ROM occurred most frequently in hand (76.7%) and elbow (38.4%). Multiple linear regression analysis revealed that only joint pain (regression coefficient: -0.504, 95% confidence interval (CI): -0.820-0.188, P ＜ 0.001) and ROM (regression coefficient: 0.017, 95% CI: 0.011-0.024, P ＜ 0.001) were independent risk factors affecting daily living and working function.

CONCLUSION

Most adult patients suffered with multiple affected joints in both upper and lower limbs. The elbow, hand and knee were the most frequently and severely affected joints. The pain and limited ROM were the independent risk factors of daily living and working function.

Effects of dietary factors on selenium levels of children to prevent Kashin-Beck disease during a high-prevalence period in an endemic area: a cohort study

Selenium (Se) supplements have been used to control Kashin-Beck disease (KBD) for decades, but the effect of diet without Se supplements is unclear because the prevalence of KBD has decreased. This matched cohort study was undertaken to determine dietary factors affecting selenium nutrition status of children living in KBD areas and the effects of Se supplements in preventing KBD. A total of 593 children aged 5-12 years were randomly selected during the high prevalence period of KBD from 1992 to 1995. Children in one village received Se supplemented (Se+) salt and were matched with three children in 16 other villages who did not receive Se supplemented (Se-) salt. A questionnaire and determinations of occipital hair Se to reflect body Se status were obtained at baseline (April 1992), at 6 months (October 1992), and yearly each April through 1995. Hair Se content in the Se+ group was significantly higher than in the Se- group (P < 0.001) at all time-points and was significantly related to the incidence of suspected KBD symptoms (P = 0.018). Four dietary factors significantly affected hair Se contents. Se levels were increased by consumption of Se+ salt (P < 0.001) and eating meat/egg often (P = 0.019) or occasionally (P = 0.001). Se levels were decreased by consumption of grain mildewed at harvest or in storage (P < 0.001 for each) and drinking ditch, river, or cellar water (P < 0.001; P = 0.002; P < 0.001, respectively). These results show that Se+ salt had a significant effect in maintaining the Se nutrition status of children in this cohort study but that dietary factors in those without Se supplements contributed as well.

Proteoglycan metabolism, cell death and Kashin-Beck disease

Kashin-Beck Disease (KBD) is an endemic, chronic and degenerative osteoarthropathy principally occurring in children. The characteristic pathological change of KBD is chondrocyte necrosis in hyaline articular cartilage. Proteoglycans are one of the major components in the extracellular matrix of articular cartilage, and disrupted proteoglycan metabolism and loss of proteoglycans in articular cartilage from KBD patients has been observed. In this mini-review, we discuss the close relationship between chondrocyte death including necrosis and loss of proteoglycan, and its potential mechanism during KBD onset and development, which may provide new clues for KBD research.

Histopathology of chondronecrosis development in knee articular cartilage in a rat model of Kashin-Beck disease using T-2 toxin and selenium deficiency conditions

The objective of this study is to observe pathogenic lesions of joint cartilages in rats fed with T-2 toxin under a selenium deficiency nutrition status in order to determine possible etiological factors causing Kashin-Beck disease (KBD). Sprague-Dawley rats were fed selenium-deficient or control diets for 4 weeks prior to their being exposed to T-2 toxin. Six dietary groups were formed and studied 4 weeks later, i.e., controls, selenium-deficient, low T-2 toxin, high T-2 toxin, selenium-deficient diet plus low T-2 toxin, and selenium-deficient diet plus high T-2 toxin. Selenium deficiencies were confirmed by the determination of glutathione peroxidase activity and selenium levels in serum. The morphology and pathology (chondronecrosis) of knee joint cartilage of experimental rats were observed using light microscopy and the expression of proteoglycans was determined by histochemical staining. Chondronecrosis in deep zone of articular cartilage of knee joints was seen in both the low and high T-2 toxin plus selenium-deficient diet groups, these chondronecrotic lesions being very similar to chondronecrosis observed in human KBD. However, the chondronecrosis observed in the rat epiphyseal growth plates of animals treated with T-2 toxin alone or T-2 toxin plus selenium-deficient diets were not similar to that found in human KBD. Our results indicate that the rat can be used as a suitable animal model for studying etiological factors contributing to the pathogenesis (chondronecrosis) observed in human KBD. However, those changes seen in epiphyseal growth plate differ from those seen in human KBD probably because of the absence of growth plate closure in the rat.

Excessive degradation of type II collagen in articular cartilage in equine osteochondrosis

Articular osteochondrosis (OCD) occurs in both man and animals. The etiology remains to be determined. Studies of OCD lesions in animals may provide clues as to its pathogenesis. The aim of our study was to determine whether there was evidence for increased degradation namely proteoglycan (PG) release and type II collagen cleavage in articular cartilage harvested from OCD lesions. We examined ex vivo explants at post-mortem from equine OCD lesions and macroscopically normal site and age matched cartilage. These were cultured over a 10 day period in serum-free medium. Type II collagen cleavage was measured in articular cartilage and media using an Elisa assay to detect the COL2-3/4C(short) epitope, which is generated on cleavage of the triple helix of type II collagen by collagenases. PG release was measured by a dye-binding assay. Cumulative release of PG and COL2-3/4C(short) and their contents in cartilage at the end of the culture period were determined. In OCD lesions there was a significant increase in type II collagen cleavage by collagenase but no evidence for increase of PG degradation. These findings point to a selective increase in type II collagen cleavage by collagenases, in OCD lesions of the kind observed in osteoarthritis. Further work is needed to determine whether changes represent primary or secondary events in the pathogenesis of OCD.

Apoptotic cell death is not a widespread phenomenon in normal aging and osteoarthritis human articular knee cartilage: a study of proliferation, programmed cell death (apoptosis), and viability of chondrocytes in normal and osteoarthritic human knee cartilage

OBJECTIVE

Chondrocytes are crucial for adequate matrix balance and function. Cell proliferation and, recently, extensive apoptotic cell death have been reported in osteoarthritic (OA) cartilage. Apoptotic cell death would be an obvious central factor in the initiation and progression of OA, since there is no potential for replacing articular chondrocytes in the adult. Therefore, we studied the occurrence of apoptotic cell disintegration and cell proliferation in OA and normal articular cartilage obtained from the knees of adult donors of all ages.

METHODS

Following immunostaining for cellular proteins as well as staining for nuclear DNA, we performed triple-channel confocal laser scanning microscopy on thick cartilage slices to evaluate lacunar emptying and cell viability. Cell proliferation and apoptotic cell death were evaluated morphologically, by immunodetection of the proliferation-associated Ki-67 antigen, and by the TUNEL reaction.

RESULTS

With the exception of the calcified layer, we were not able to detect any major (apoptotic or nonapoptotic) cell disintegration in normal young or aged articular knee cartilage. Single apoptotic cells were detected in OA articular knee cartilage. A significant increase in lacunar emptying was observed in late-stage specimens with higher Mankin scores compared with age-matched normal control cartilage specimens, but not in low-grade lesions. A significant (but lesser) increase in empty lacunae was also observed with age in normal cartilage. Cell proliferation was rarely detected in OA cartilage samples and was not detected at all in normal cartilage samples.

CONCLUSION

Our results confirm the findings of previous studies showing that cell proliferation occurs in OA cartilage. They also show that, contrary to previous suggestions, apoptotic cell death is not a widespread phenomenon in aging or OA cartilage.

Alterations in cartilage type-II procollagen and aggrecan contents in synovial fluid in equine osteochondrosis

The etiology and pathophysiology of osteochondrosis remain poorly understood because it is difficult to obtain material from lesions in the early stage of this disease and because there is no satisfactory experimental animal model. We wished to determine whether there are changes in articular cartilage turnover in equine osteochondrosis, which closely resembles the human disease, by assaying cartilage matrix molecules in synovial fluids. We used immunoassays that measure a keratan sulfate epitope and the epitope 846 on the cartilage proteoglycan aggrecan and the C-propeptide of cartilage type-II procollagen, which is released following the synthesis of this molecule, to analyse synovial fluids from equine tarsocrural joints with and without osteochondrosis. In young horses with osteochondrosis, there was a significant increase of C-propeptide of type-II procollagen accompanied by a decrease in the 846 and keratan sulfate epitopes. The results identify differential alterations in aggrecan and type-II collagen turnover in the cartilage matrix in young animals with osteochondrosis that may contribute to the pathological degeneration of articular cartilage in this disease.

Kashin-Beck osteoarthropathy in rural Tibet in relation to selenium and iodine status

BACKGROUND AND METHODS

Kashin-Beck disease is a degenerative osteoarticular disorder that is endemic to certain areas of Tibet, where selenium deficiency is also endemic. Because selenium is involved in thyroid hormone metabolism, we studied the relation among the serum selenium concentration, thyroid function, and Kashin-Beck disease in 575 subjects 5 to 15 years of age in 12 villages around Lhasa, Tibet, including 1 control village in which no subject had Kashin-Beck disease. Clinical, radiologic, and biochemical data were collected.

RESULTS

Among the 575 subjects, 280 (49 percent) had Kashin-Beck disease, 267 (46 percent) had goiter, and 7 (1 percent) had cretinism. Of the 557 subjects in whom urinary iodine was measured, 66 percent had a urinary iodine concentration of less than 2 microg per deciliter (157 nmol per liter; normal, 5 to 25 microg per deciliter [394 to 1968 nmol per liter]). The mean urinary iodine concentration was lower in subjects with Kashin-Beck disease than in control subjects (1.2 vs. 1.8 microg per deciliter [94 vs. 142 nmol per liter], P<0.001) and hypothyroidism was more frequent (23 percent vs. 4 percent, P=0.01). Severe selenium deficiency was documented in all villages; 38 percent of subjects had serum concentrations of less than 5 ng per milliliter (64 nmol per liter; normal, 60 to 105 ng per milliliter [762 to 1334 nmol per liter]). When age and sex were controlled for in a multivariate analysis, low urinary iodine, high serum thyrotropin, and low serum thyroxine-binding globulin values were associated with an increased risk of Kashin-Beck disease, but a low serum selenium concentration was not.

CONCLUSIONS

In areas where severe selenium deficiency is endemic, iodine deficiency is a risk factor for Kashin-Beck disease.