Liver disease in rheumatoid arthritis and Sjøgren's syndrome. Prospective study using biochemical and serological markers of hepatic dysfunction

Multifaceted mitochondrial as a novel therapeutic target in dry eye: insights and interventions

Dry eye, recognized as the most prevalent ocular surface disorder, has risen to prominence as a significant public health issue, adversely impacting the quality of life for individuals across the globe. Despite decades of extensive research into the chronic inflammation that characterizes dry eye, the intricate mechanisms fueling this persistent inflammatory state remain incompletely understood. Among the various cellular components under investigation, mitochondria-essential for cellular energy production and homeostasis-have attracted increasing attention for their role in dry eye pathogenesis. This involvement points to mechanisms such as oxidative stress, apoptosis, and sustained inflammation, which are central to the progression of the disease. This review aims to provide a thorough exploration of mitochondrial dysfunction in dry eye, shedding light on the critical roles played by mitochondrial oxidative stress, apoptosis, and mitochondrial DNA damage. It delves into the mechanisms through which diverse pathogenic factors may trigger mitochondrial dysfunction, thereby contributing to the onset and exacerbation of dry eye. Furthermore, it lays the groundwork for an overview of current therapeutic strategies that specifically target mitochondrial dysfunction, underscoring their potential in managing this complex condition. By spotlighting this burgeoning area of research, our review seeks to catalyze the development of innovative drug discovery and therapeutic approaches. The ultimate goal is to unlock promising avenues for the future management of dry eye, potentially revolutionizing treatment paradigms and improving patient outcomes. Through this comprehensive examination, we endeavor to enrich the scientific community's understanding of dry eye and inspire novel interventions that address the underlying mitochondrial dysfunctions contributing to this widespread disorder.

Autoimmune Liver Diseases and Rheumatoid Arthritis-Is There an Etiopathogenic Link?

Rheumatoid arthritis (RA) is a systemic immune-mediated disease that, in addition to the articular involvement, can have extra-articular manifestations. Even though liver damage in RA is not very common, associated autoimmune liver diseases (AILDs) may occur. The most common AILD associated with RA is primary biliary cirrhosis (PBC), followed by autoimmune hepatitis (AIH) and primary sclerosing cholangitis (PSC). There are common underlying mechanisms that play a role in the emergence of autoimmunity and inflammation in both rheumatic and autoimmune liver diseases. Genetic studies have revealed the existence of several common disease-associated genes shared between RA and AILDs, and infectious triggers, particularly those associated with recurrent or complicated urinary tract infections, are also speculated to be potential triggers for these conditions. Moreover, these diseases share common serologic patterns characterized by the presence of specific autoantibodies and hyper-gammaglobulinemia. In this study, we focus on reviewing the association between RA and AILDs regarding the prevalence and possible etiopathogenic link.

High-Sucrose Diet Accelerates Arthritis Progression in a Collagen-Induced Rheumatoid Arthritis Model

SCOPE

High dietary sugar and sweeteners are suspected to cause the development of rheumatoid arthritis (RA) symptoms through the induction of proinflammatory cytokine release. However, the mechanisms by which increased dietary sugar affects RA etiology are not yet fully understood. The study uses a mouse model of collagen-induced RA (CIA) to investigate the relationship between excessive sugar consumption and RA risk.

METHODS AND RESULTS

RA-associated pathological features are assessed in the nonimmunized (NI) control group, the CIA-positive control group, and the CIA + high-sucrose diet (CIA+HS, 63% calories from sucrose) group. Compared with the CIA group, the CIA+HS group shows a greater increase in paw thickness and clinical scores, as well as, a higher degree of pannus formation and inflammation in the knee, ankle, and sole tissues. Moreover, the infiltration of immune cells is increased in the CIA+HS group. Although the expression of hepatic lipogenic genes, is not altered, that of toll-like receptor (TLR4) and IL-1β is considerably elevated in the CIA+HS group.

CONCLUSIONS

These findings suggest that excessive sucrose consumption causes hepatic fibrosis and inflammation, contributing to the pathophysiology of RA.

Rheumatoid arthritis: Extra-articular manifestations and comorbidities

Although synovitis is the pathological hallmark of rheumatoid arthritis (RA), many extra-articular manifestations (EMs) and comorbidities likely occur due to the complex, chronic, inflammatory, and autoimmune features of RA. Cardiovascular (CV) disease is the most common cause of death in patients with RA. Compared to the general population, patients with RA have twice the risk of myocardial infarction and up to 50% increased CV mortality risk. Severe and prolonged disease activity, genetics, and inflammation (e.g. CRP, ACPA, cytokines, matrix-degrading enzymes) play important roles in CV disease and atheroscleroticdamage. The second major cause of death in patients with RA is respiratory disease, which occurs in 30-40% of patients. RA may affect the lung interstitium, airways, and pleurae, while pulmonary vascular involvement is less frequent. Central and peripheral nervous system involvement is usually due to small vessel vasculitis, joint damage, or drug toxicity. There is also evidence that microvascular cerebral damage caused by systemic inflammation is associated with the development of Alzheimer's disease and vascular dementia. Some observational studies have hinted how Disease Modified Anti-Rheumatic Drugs and biologics could reduce the incidence of dementia. Primary gastrointestinal and renal involvements are rare and often relate to drug therapy. To minimize morbidity and mortality, physicians must manage RA disease activity (treat-to-target) and monitor risk factors and concomitant conditions (e.g. smoking cessation; weight regulation; monitoring blood pressure, lipids, thyroid hormone, folic acid and homocysteine; screening for depression, anxiety, atlantoaxial instability, and atherosclerosis). This article aims to provide an overview of the most prevalent and important EMs and comorbidities associated with RA.

Rheumatoid arthritis: Recent advances on its etiology, role of cytokines and pharmacotherapy

An autoimmune disease is defined as a clinical syndrome resulted from an instigation of both T cell and B cell or individually, in the absence of any present infection or any sort of distinguishable cause. Clonal deletion of auto reactive cells remains the central canon of immunology for decades, keeping the role of T cell and B cell aside, which are actually the guards to recognize the entry of foreign body. According to NIH, 23.5 million Americans are all together affected by these diseases. They are rare, but with the exception of RA. Rheumatoid arthritis is chronic and systemic autoimmune response to the multiple joints with unknown ethology, progressive disability, systemic complications, early death and high socioeconomic costs. Its ancient disease with an old history found in North American tribes since 1500 BCE, but its etiology is yet to be explored. Current conventional and biological therapies used for RA are not fulfilling the need of the patients but give only partial responses. There is a lack of consistent and liable biomarkers of prognosis therapeutic response, and toxicity. Rheumatoid arthritis is characterized by hyperplasic synovium, production of cytokines, chemokines, autoantibodies like rheumatoid factor (RF) and anticitrullinated protein antibody (ACPA), osteoclastogensis, angiogenesis and systemic consequences like cardiovascular, pulmonary, psychological, and skeletal disorders. Cytokines, a diverse group of polypeptides, play critical role in the pathogenesis of RA. Their involvement in autoimmune diseases is a rapidly growing area of biological and clinical research. Among the proinflammatory cytokines, IL-1α/β and TNF-α trigger the intracellular molecular signalling pathway responsible for the pathogenesis of RA that leads to the activation of mesenchymal cell, recruitment of innate and adaptive immune system cells, activation of synoviocytes which in term activates various mediators including tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6) and interleukin-8 (IL-8), resulting in inflamed synovium, increase angiogenesis and decrease lymphangiogensis. Their current pharmacotherapy should focus on their three phases of progression i.e. prearthritis phase, transition phase and clinical phase. In this way we will be able to find a way to keep the balance between the pro and anti-inflammatory cytokines that is believe to be the dogma of pathogenesis of RA. For this we need to explore new agents, whether from synthetic or natural source to find the answers for unresolved etiology of autoimmune diseases and to provide a quality of life to the patients suffering from these diseases specifically RA.

Immune Components of Liver Damage Associated with Connective Tissue Diseases

Autoimmune connective tissue diseases are associated with liver abnormalities and often have overlapping pathological and clinical manifestations. As a result, they can present great clinical challenges and evoke questions about diagnostic criteria for liver diseases. Moreover, discriminating between liver involvement as a manifestation of connective tissue disease and primary liver disease can be challenging since they share a similar immunological mechanism. Most patients with connective tissue diseases exhibit liver test abnormalities that likely result from coexisting, primary liver diseases, such as fatty liver disease, viral hepatitis, primary biliary cirrhosis, autoimmune hepatitis, and drug-related liver toxicity. Liver damage can be progressive, leading to cirrhosis, complications of portal hypertension, and liver-related death, and, therefore, must be accurately identified. In this review, we highlight the challenges facing the diagnosis of liver damage associated with connective tissue disease and identify immune mechanisms involved in liver damage associated with connective tissue diseases.

Anaesthesia management for acute appendicitis in cases with Sjogren's syndrome accompanying autoimmune hepatitis

Characterised by lymphocytic infiltration of exocrine glands, Sjögren's syndrome (SS) is a chronic autoimmune disease. Symptoms belonging to the involved systems may occur owing to the fact that it affects multiple systems. While rheumatoid arthritis is observed concomitantly, its co-occurrence with autoimmune hepatitis is astonishingly common. Through this case report, we intended to review issues that should be attended to while administering anaesthesia to a patient with SS accompanying autoimmune hepatitis. In the light of literature, we aimed to discuss anaesthesia management to the patient with SS and issues stemming from the clinical features of SS. In SS, the expected issues are liver problems related autoimmune hepatitis and respiratory problems related pulmonary fibrosis. A careful preoperative evaluation, a comprehensive preparation against difficulty in intubation, a selective anaesthesia management in terms of autoimmune hepatitis and close monitoring of postoperative respiration may prevent or decrease possible complications.

The spectrum of rheumatoid arthritis in patients attending rheumatology clinic in nizwa hospital-oman

OBJECTIVES

To determine the spectrum and expression of rheumatoid arthritis (RA) in patients attending the rheumatology clinic in Nizwa hospital, Oman.

METHODS

SUBJECTS AND METHODS

66 patients fulfilling the American College of Rheumatology (ACR) criteria for the diagnosis of RA were included in the study. The patients were either attending for the first time or were already diagnosed and attending for follow up. The demographic, clinical, laboratory and radiological findings are reported.

RESULTS

Of the 66 patients studied, 16 were males and 50 were females. The mean age of patients at onset was 44.5 ±14.5 years, and the females were younger than males at presentation. 38 (57.57%) were seropositive and two (3.03%) only had rheumatoid nodules. The majority of the patients were considered as class 1 or 2 according to the ACR functional classification. The commonest extra-articular manifestation was anaemia (27.27%) followed by keratoconjuctivitis sicca (24.42%). The upper limb joints were affected more than the lower limbs and the most commonly involved joint was the wrist (81%) followed by the metacarpophalangeal (MCP) (66.66%) joints, the knee (57.57%), ankle (45.45%), elbow (42.42%), shoulder (42.42%), and the proximal interphalangeal (PIP) (36.36%) joints. The main associated diseases were hypertension (21%), ischemic heart disease (13.63%) and diabetes mellitus (9.03%). Systemic features were predominantly morning stiffness (84.5%) and fatigue (45.45%). Reported deaths were due to sepsis and cardiac arrhythmia. Thus 63 (95.45%) of the patients were on conventional disease modifying antirheumatic drugs.

CONCLUSIONS

Demographic characteristics were similar to those reported by others, the seropositivity rate and nodular form of the disease was less in the studied patients and the disease seemed milder than that reported in western countries.

Gastrointestinal and hepatic manifestations of rheumatoid arthritis

Rheumatoid arthritis (RA), characterized by inflammation of the synovium and surrounding structures, has a prevalence of 0.5-1%. Rheumatoid vasculitis (RV) is an inflammatory condition of the small- and medium-sized vessels that affects up to 5% of patients with RA with intestinal involvement in 10-38% of these cases. Clinically apparent RV of the gastrointestinal (GI) tract, while rare, is often catastrophic, resulting in ischemic ulcers and bowel infarction. Vasculitis of the colon may present as pancolitis clinically similar to ulcerative colitis. Rectal biopsies that include submucosal vessels are positive for vasculitis in up to 40% of cases. Abnormal esophageal motility in RA may result in heartburn and dysphagia. Chronic atrophic gastritis may be associated with hypergastrinemia and hypo- or achlorhydria, promoting small bowel bacterial overgrowth. RA is the most common cause of secondary amyloidosis with GI symptoms in 22% of affected patients. Although amyloid is usually found in the liver, it is rarely evident clinically. Felty's syndrome occurs in less than 1% of patients with RA and is characterized by neutropenia and splenomegaly. The liver may be involved with portal fibrosis or nodular regenerative hyperplasia. Liver histology is abnormal in 92% of RA patients at autopsy, although the changes are usually mild without associated hepatomegaly. Drug-induced liver disease may occur with aspirin, sulfasalazine, and methotrexate. Significant liver damage is rare if the drug is discontinued or the patient is properly monitored. RA can affect both the GI tract and the liver; changes are usually mild except with RV.

Rheumatologic disease and the liver

Rheumatologic diseases such as rheumatoid arthritis, systemic lupus erythematosus, Sjögren syndrome, and scleroderma are immunologically mediated disorders that typically have multisystem involvement. Although clinically significant liver involvement is rare, liver enzyme abnormalities may be observed in up to 43% of patients. The biochemical abnormalities are typically mild and transient and the histologic abnormalities are usually nonprogressive. Such biochemical and histologic findings are typically ascribed to the primary rheumatologic condition and require no specific management. In a subset of patients with rheumatologic conditions and liver test abnormalities, further evaluation identifies a coexisting, primary liver disease or medication-related liver toxicity as the cause of the biochemical abnormality. Liver test abnormalities in patients with a coexisting primary liver disease are more likely to be persistent. In such cases, further workup using serologic tests, appropriate imaging studies and liver biopsy may be needed to accurately identify the cause of liver test abnormalities. This article reviews the spectrum of liver-related abnormalities associated with several rheumatologic diseases. Hepatotoxicity related to medications commonly prescribed in such conditions is also discussed.

Autoimmune hepatitis in patients with primary Sjögren's syndrome: a series of two-hundred and two patients

Based on the revised criteria of the American-European Consensus Group, we retrospectively established the diagnosis of primary or secondary Sjögren's syndrome for 202 patients referred to a Sjögren's syndrome clinic. Of these, 58 patients and 8 patients fulfilled criteria for primary and secondary Sjögren's syndrome, respectively. Of the 58 patients with primary Sjögren's syndrome, one (1.7%) had definite autoimmune hepatitis, as defined by the International Autoimmune Hepatitis Group diagnostic criteria. One additional symptomatic patient who did not fulfill criteria for primary Sjögren's syndrome had definite autoimmune hepatitis. None of the patients with secondary Sjögren's syndrome had definite autoimmune hepatitis. Two (1%) of the 194 patients with primary Sjögren's syndrome or clinical symptoms had primary biliary cirrhosis. These values are lower than those reported by prior studies with smaller patient populations and likely represent a more accurate estimate of the true prevalence of these diseases in patients with primary Sjögren's syndrome.

The involvement of the liver in systemic diseases

The liver has a double blood supply and plays a central role in the metabolism of proteins, carbohydrates, and many medications. In addition, it has a role in the induction of immune tolerance and may also be a target for immune-mediated damage. For these reasons, the liver may be involved in many systemic diseases. In this review, we discuss the involvement of the liver in granulomatous, rheumatologic, malignant, and circulatory diseases. An understanding of the wide spectrum of liver involvement in systemic diseases will aid in both diagnosis and treatment of patients with a wide range of medical conditions.

Hepatic centrilobular zonal necrosis with positive antinuclear antibody: a unique subtype or early disease of autoimmune hepatitis?

Centrilobular zonal necrosis (CZN) is not a pattern typically associated with autoimmune hepatitis (AIH). However, it has occasionally been reported that CZN occurs without the classic histologic features of AIH in patients with autoimmune abnormalities. In this study, we examined the clinicopathological features of 5 cases of CZN with autoimmune features not associated with classic AIH. The patients were 1 man and 4 women (24-82 years). Three patients had subjective symptoms (general malaise, arthralgia, and fever). All had antinuclear antibodies (1:40 to 1:1280). Liver biopsy showed CZN without any histologic features of classic AIH. Liver injury was sustained without medication in 4 cases, whereas it was spontaneously improved in 1 case. However, 2 months later, this patient was found to have recurrent liver dysfunction. Liver biopsy at the time of recurrence again showed CZN without the features of classic AIH. All patients were effectively treated with prednisone. Based on a review of a total of 17 cases of CZN with autoimmune features, including previously reported cases, the patients could be classified into 3 groups: cases without recurrence, cases with recurrent CZN, and cases with progression to classic AIH. Patients of the 2 former groups did not develop classic AIH during follow-up. Factors predictive of recurrence were younger age, being male, and high serum bilirubin or transaminase concentrations at first presentation (P < .05). This study suggested that CZN with autoimmune features corresponds to the early stage of classic AIH in some cases and might be a distinct type of autoimmune liver disease in others.

Hepatic manifestations of autoimmune rheumatic diseases

Hepatic manifestations in autoimmune disease include chronic active hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, and nodular regenerative hyperplasia. These diseases are rare and may occur concomitantly or serially. Clinicians must be aware of the possibility of liver disease so that it can be treated as soon as possible.

Do autoantibodies predict autoimmune liver disease in primary Sjögren's syndrome? Data of 180 patients upon a 5 year follow-up

OBJECTIVE

To evaluate the clinical value of autoantibodies as serological markers to predict autoimmune liver diseases in primary Sjögren's syndrome (SS).

MATERIALS AND METHODS

180 patients who met the European diagnostic criteria for SS but without a history of liver disease were studied upon a 5 year follow-up. Sera taken at enrolment were evaluated by immunofluorescence analysis (IF-AMA) on rat liver, stomach and kidney sections, enzyme-linked immunosorbent assay using rat mitochondrial, microsomal and soluble liver antigens and Western blot (WB) analysis using rat mitochondrial antigens.

RESULTS

At presentation, 152 (84%) sera had autoantibodies. Antinuclear antibodies (ANA) were expressed in 58% of patients and displayed three distinct patterns (speckled, homogenous and anticentromere). Smooth muscle autoantibodies (SMAs) and parietal cell autoantibodies were found in 39 and 4.5% of patients, respectively. Three patients presented antimitochondrial antibodies by IF-AMA, and two of them developed symptomatic primary biliary cirrhosis (PBC). Two patients without IF-AMA and without evidence of cholestasis had PBC-specific AMA (anti-PDC-E2 and anti-BCKADC-E2). However, these two patients and the third IF-AMA-positive woman remained free from symptoms and biochemical signs of PBC. Autoimmune hepatitis (AIH) (n = 2), 'overlap syndrome' of AIH and chronic hepatitis C (n = 1) and autoimmune cholangiopathy (AIC) (n = 1) were diagnosed in four patients.

CONCLUSIONS

Patients with IF-AMA usually develop symptomatic PBC upon a 5 year follow-up. Our findings support the idea that patients without IF-AMA, who express PBC-specific AMA, are in early, asymptomatic stage of the disease. High-titre SMA and IF-AMA are the most specific indicators for AIH and PBC.

Connective tissue diseases and the liver

Connective tissue diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis, Sjögren's syndrome, and scleroderma are systemic disorders that may have an autoimmune basis. The system manifestations vary, and there is frequent overlap among the syndromes. Liver involvement in patients with connective tissue diseases has been well documented but is generally considered rare. Although advanced liver disease with cirrhosis and liver failure is rare in patients with connective tissue diseases, clinical and biochemical evidence of associated liver abnormalities is common. Previous treatment with potentially hepatotoxic drugs or coincident viral hepatitis has usually been implicated as the main causes of liver disease in patients with connective tissue diseases. However, even after careful exclusion of these etiologies, the question remains whether to classify the patient as having a primary liver disease with associated autoimmune, clinical, and laboratory features or as having liver disease as a manifestation of generalized connective tissue disease. The main example of this pathogenetic dilemma is autoimmune hepatitis and SLE-associated hepatitis, which have been regarded as two different entities, although they have features in common of autoimmune syndromes. Several clinical and histopathologic features have been used to discriminate autoimmune hepatitis from SLE, a relevant diagnostic exercise because complications and therapy are quite different. Although hepatic steatosis and abnormal results on biochemical liver function tests are the most common hepatic abnormalities associated with connective tissue diseases, other less frequent abnormalities have been noted, such as nodular regenerative hyperplasia, portal vein obliteration and portal hypertension, features of primary biliary cirrhosis, and rarely portal fibrosis with abnormal lobular architecture. Vascular disorders of the liver also have been described, such as Budd-Chiari syndrome. Histologic assessment may reveal a variety of subclinical liver diseases. The aim of this contribution is to review the current published data regarding liver involvement in connective tissue diseases.

The liver is a common non-exocrine target in primary Sjögren's syndrome: a retrospective review

BACKGROUND

The autoimmune destruction of exocrine glands that defines primary Sjögren's syndrome (1 degrees SS) often extends to non-exocrine organs including the liver. We aimed to determine the prevalence of liver disease in patients with 1 degrees SS and to evaluate the association of this complication with other non-exocrine features and serologic markers of autoimmunity and systemic inflammation.

METHODS

We reviewed 115 charts of patients with 1 degrees SS and further analyzed the 73 cases that fulfilled the European Epidemiology Center Criteria, seeking evidence for clinical and subclinical liver disease.

RESULTS

Liver function tests had been determined in 59 of the 73 patients. Of those, 29 patients (49.1%) had abnormal liver function tests including 20.3% with clinically overt hepatic disease. Liver disease was the most common non-exocrine feature in this cohort. Risk factors for abnormal liver function tests were distributed similarly between the patients with and without liver disease. In 60% of patients with abnormal liver function tests no explanation for this complication was found except for 1 degrees SS. Liver involvement was significantly more common in 1 degrees SS patients who also had evidence of lung, kidney and hematological abnormalities. Patients with abnormal liver function tests were also more likely to have an elevated sedimentation rate and a positive anti-ENA during the course of their disease.

CONCLUSION

Liver involvement is a common complication in 1 degrees SS. Its presence correlates with systemic disease. We consider that this complication should be routinely sought in patients with 1 degrees SS, especially when a positive anti-ENA or evidence of systemic inflammation is found.

The effects of vasculitis on the gastrointestinal tract and liver

Vasculitis can affect every organ of the digestive system. In many cases, it may first present with gastrointestinal symptoms. In several forms of vasculitis, including Churg Strauss syndrome, Henoch-Schönlein purpura, and lupus, the majority of patients have gastrointestinal involvement. The astute gastroenterologist should consider vasculitic causes of the symptoms seen in many patients. Making the correct diagnosis requires a thorough understanding of the potential role of vasculitis in causing these symptoms and the appropriate path to making a diagnosis. This article reviews the variety of manifestations of vasculitis on the digestive system, and emphasizes diagnosis and clinical manifestations.

Splenic involvement in rheumatic diseases

OBJECTIVES

To assess the major reports of splenic involvement in the rheumatic diseases and to highlight several conditions in which potentially life-threatening splenic complications may occur.

METHODS

A search of the Medline database ('SilverPlatter': 1966 to 1997) was conducted for all English-language entries related to the spleen and the major rheumatic diseases. Original articles were reviewed from the bibliographies of these Medline-sourced articles. The major rheumatological textbooks were also reviewed for original references.

RESULTS

Patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and polyarteritis nodosa (PAN) are at risk of experiencing spontaneous splenic rupture. Splenomegaly is common in both uncomplicated RA and as a feature of Felty's syndrome, in which the patient may be at risk of splenic abscess formation, again a possible complication of SLE and also PAN. Massive splenomegaly appears to be specific to SLE and may be confused with a malignant process. Abnormal splenic function has been documented in RA, SLE, and Wegener's granulomatosis. The spleen may show areas of infarction in several conditions, notably SLE and Wegener's granulomatosis. Splenic atrophy is not uncommon in SLE and may be associated with functional asplenia and a co-incident risk of potentially fatal infection with capsulated organisms.

CONCLUSIONS

Serious and occasionally fatal complications within the spleen occur in many rheumatic diseases. Prompt recognition of these complications is important.

Osteocalcin in canine joint diseases

Markers of joint disease are much sought after in human and veterinary rheumatology. This study investigated the relationship between markers of bone and cartilage turnover in sera and synovial fluids in naturally occurring canine joint diseases. Osteocalcin (OC) was measured by radioimmunoassay; enzyme-linked immunosorbent assays were used to measure keratan sulphate, chondroitin sulphate, hyaluronan and antibodies to collagen I and II. Dimethylmethylene blue binding assay was used for the estimation of sulphated glycosaminoglycans. Compared to normal dogs significantly higher serum OC was seen in dogs with osteoarthritis (P < 0.005), rheumatoid arthritis (RA) (P < 0.01) and rupture/stretching of cranial cruciate ligament (P < 0.02). Reduced OC was found in RA synovial fluids but this finding is probably of little value as there was too much overlap with normal joint data. Apart from a weak correlation between synovial fluid OC and keratan sulphate, there were generally no correlations between markers of bone and cartilage turnover probably reflecting the lack of any relationship between bone and cartilage metabolism in most canine arthropathies.

Autoimmune liver disease in patients with primary Sjögren's syndrome

Forty-five patients with primary Sjögren's syndrome were studied for evidence of autoimmune liver disease. Twenty-nine patients had normal liver function tests, normal IgM and a normal test for antimitochondrial antibodies and smooth muscle antibodies. Among the remaining 16 patients, abnormal liver function tests were found in 12 (27% of all patients); eight of these patients had biochemical cholestasis. Elevated plasma IgM (> 2 g/l) was observed in nine patients, three with normal liver function tests, while antimitochondrial antibodies were positive in six patients, one with normal liver function tests, and smooth muscle antibodies were found in three. Based on these findings and percutaneous liver biopsy, a diagnosis of primary biliary cirrhosis was established in four patients and autoimmune chronic active hepatitis in two. The present study showed that abnormal liver function tests in patients with primary Sjögren's syndrome are frequent and may indicate associated autoimmune liver disease. These data further emphasize the systemic nature of autoimmune disorders.

Interpretation and clinical significance of alkaline phosphatase isoenzyme patterns

Alkaline phosphatase (ALP, EC 3.1.3.1) is a membrane-bound metalloenzyme that consists of a group of true isoenzymes, all glycoproteins, encoded for by at least four different gene loci: tissue-nonspecific, intestinal, placental, and germ-cell ALP. Through posttranslational modifications of the tissue-nonspecific gene, for example, through differences in carbohydrate composition, bone and liver ALP are formed. Nowadays, most commercially available methods for separating or measuring ALP isoenzymes are easy to perform and sensitive and allow for reproducible and quantitative results. As more isoenzymes and isoforms have been characterized, confusion has arisen due to the many different names they were given. For the sake of simplicity and because of structural analogies, we propose an alternative nomenclature for the ALP isoenzymes and isoforms based on their structural characteristics: soluble, dimeric (Sol), anchor-bearing (Anch), and membrane-bound (Mem) liver, bone, intestinal, and placental ALP. Together with lipoprotein-bound liver ALP and immunoglobulin-bound ALP, these names largely fit the many forms of ALP one can encounter in human serum and tissues. The clinically relevant isoenzymes are sol-liver, Mem-liver, lipoprotein-bound liver, and Sol-intestinal ALP in liver diseases, and Sol-bone and Anch-bone ALP in bone diseases. Many different isoenzyme patterns can be found in malignancies and renal diseases. This test provides the clinician with valuable information for diagnostic purposes as well as for follow-up of patients and monitoring of treatment. However, ALP isoenzyme determination will only provide clinically useful information if the patterns are correctly interpreted. In this respect, care should be taken to use the proper reference ranges, taking into account the age and sex of the patient. A normal total ALP activity does not rule out the presence of an abnormal isoenzyme pattern, particularly in children. Separating ALP into its isoenzymes adds considerable value to the mere assay of total ALP activity.

Alkaline phosphatase isoenzyme activities in rheumatoid arthritis: hepatobiliary enzyme dissociation and relation to disease activity

OBJECTIVES

Hyperphosphatasaemia has been observed occasionally in patients with rheumatoid arthritis (RA), and it has been suggested that the serum alkaline phosphatase (ALP) level is related to the activity of the disease. Therefore, the relationship between serum ALP and RA was studied.

METHODS

The serum activities of hepatobiliary enzymes (ALP isoenzymes, gamma-glutamyltranspeptidase (GTP), leucine aminopeptidase (LAP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT)), immunoglobulins, RA haemagglutinin test (RAHA), C reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were observed in 288 patients with rheumatoid arthritis.

RESULTS

Serum biliary ALP (ALP1) activity was detected in 31.6% of the patients. In patients positive for ALP1 the respective values of total ALP (ALPt) (p < 0.001), liver ALP (ALP2) (p < 0.001), bone ALP (ALP3) (p < 0.05), gamma-GTP (p < 0.001), LAP (p < 0.001), immunoglobulins IgG (p < 0.01), IgA (p < 0.01), and IgM (p < 0.01), RAHA (p < 0.001), CRP (p < 0.001), ESR (p < 0.001), and articular index (p < 0.001) were significantly higher than in patients who did not have ALP1. Significant Spearman's rank correlations (rs) were demonstrated between serum ALP2 level and the respective values of ALPt (rs = 0.9128, p < 0.001), ALP1 (rs = 0.4443, p < 0.001), ALP3 (rs = 0.5898, p < 0.001), gamma-GTP (rs = 0.2903, p < 0.001), LAP (rs = 0.3093, p < 0.001), IgA (rs = 0.2299, p < 0.01), IgM (rs = 0.1773, p < 0.05), RAHA (rs = 0.2420, p < 0.01), CRP (rs = 0.3532, p < 0.001), ESR (rs = 0.4006, p < 0.001). the articular index (rs = 0.4006, p < 0.001). However, no significant difference or correlation was noted for either AST or ALT. In many patients who showed abnormal hyperphosphatasaemia, hepatobiliary enzyme dissociation was observed: levels of ALPt (in 12.8%), ALP1 (in 31.6%), ALP2 (18.8%), gamma-GTP (in 4.3%), and LAP (in 19.3%) were abnormally high, but both AST and ALT were within normal limits.

CONCLUSION

These findings are considered to be characteristic of RA, and suggest the existence of latent or subclinical hepatobiliary involvement and an association between the expansion of hepatobiliary involvement and the mechanism of disease activation. Thus measurement of the serum levels of ALP and its isoenzymes in RA is considered to be important.

Clinical pharmacokinetics of drugs used in juvenile arthritis

Juvenile arthritis is defined as the occurrence of objective evidence of arthritis for a minimum of 6 weeks, in a child 16 years of age or younger. With a reported incidence of 9 to 19.6 per 100,000 children, juvenile arthritis is considered to be a rare disease. There is no known cure; however, up to 75% of patients will undergo remission by late adolescence. Drugs used in the treatment of juvenile arthritis are divided into 2 major classes: (a) the nonsteroidal anti-inflammatory drugs (NSAIDs) including salicylates, naproxen, ibuprofen, fenoprofen, ketoprofen, flurbiprofen, indomethacin, sulindac, tolmetin and diclofenac, and (b) disease modifying agents which encompass drugs such as antimalarial agents, gold, methotrexate, penicillamine and sulfasalazine. In almost all the reports dealing with the pharmacokinetics of NSAIDs, the level of disease activity has not been noted. The level of activity is important since, during a flare, the plasma albumin may fall to the point that it causes a substantial and clinically significant increase in the unbound serum concentration of highly bound drugs. The relationship between the concentration of these drugs in the systemic circulation and their efficacy is not clear. However, for many of them, therapeutic drug monitoring is recommended as a means of reducing the possibility of toxic reactions. Further pharmacokinetic and -dynamic evaluations are needed for many of these drugs in juvenile arthritis.

Sjögren's syndrome and the gut

Sjögren's syndrome is the result of lymphocyte-mediated destruction of exocrine glands that leads to diminished or absent glandular secretions and mucosal dryness. The manifestations from the alimentary system in patients with Sjögren's syndrome include, within the mouth, mucosal dryness, atrophy, accelerated dental decay and enlargement of the major salivary glands. Dysphagia is a common complaint and is probably secondary to oesophageal dysfunction. The symptoms from gastric involvement are nausea, epigastric pain and dyspepsia which might be attributable to chronic atrophic gastritis. Whether the small bowel is affected in Sjögren's syndrome patients is not clear. However, nutritional deficiencies have been noted in these patients. Pancreatic involvement is perhaps expressed as subclinical, acute or chronic pancreatitis, and finally there have been a large number of studies dealing with liver involvement in Sjögren's syndrome. From these reports it is clear that many patients with Sjögren's syndrome have abnormal biochemical liver function tests and some of them may also have abnormal liver biopsy. The pathogenic process responsible for the hepatic damage and for the salivary gland destruction could be similar.

Influence of non-steroidal anti-inflammatory drugs and disease activity on serum alkaline phosphatase concentrations in rheumatoid arthritis, osteoarthritis, and polymyalgia rheumatica

The influence of non-steroidal anti-inflammatory drugs (NSAIDs) and of disease activity on the serum alkaline phosphatase concentration was examined in patients with rheumatoid arthritis, osteoarthritis, and polymyalgia rheumatica. Concentrations of serum alkaline phosphatase were similar both in patients with rheumatoid arthritis taking NSAIDs and in those not taking NSAIDs. In patients with osteoarthritis NSAID use was not associated with a significant increase in serum alkaline phosphatase. In rheumatoid arthritis no correlation was found between clinical indices of disease activity and serum alkaline phosphatase concentrations. There was significant correlation with plasma viscosity in rheumatoid arthritis, both in those taking and not taking NSAIDs, and in polymyalgia rheumatica. Serum alkaline phosphatase concentrations are not influenced by NSAIDs. Concentrations correlate with laboratory parameters, but not clinical indices of disease activity.

Alkaline phosphatase isoenzymes in rheumatic diseases

Serum alkaline phosphatase isoenzymes were determined quantitatively by electrophoresis on cellulose acetate in 168 patients with rheumatic diseases subgrouped for disease activity. Median values of total alkaline phosphatase and bone isoenzyme activity, as well as frequency of patients showing pathological values, increased gradually and significantly corresponding to disease activity in rheumatoid arthritis and ankylosing spondylitis, from 0% in inactive to 90% in very active forms. Bone isoenzyme was much more sensitive than total alkaline phosphatase in moderate disease activity and was also correlated to the number of involved extravertebral joints and pain in ankylosing spondylitis. No correlation was found with stage or duration of disease, age, sex, and erythrocyte sedimentation rate. Additional to bone isoenzyme, liver isoenzymes were elevated in some patients, but with only a weak correlation with disease activity. The intestinal isoenzymes were always normal. We conclude that quantitative determination of serum alkaline phosphatase bone isoenzyme activity is a major indicator for the assessment of disease activity and therapeutic monitoring in rheumatoid arthritis and ankylosing spondylitis.

Rheumatoid arthritis in blacks in South Africa

The spectrum of rheumatoid arthritis (RA) was studied in a group of 52 blacks who attended a rheumatology unit in Cape Town, South Africa. The mean age of the patients was 44.6 years, and the female to male ratio was 3.7:1. Significant radiographic changes were frequently noted, and the mean Larsen scores were 34.9 for the hands, 19.6 for the feet, and 6.6 for the wrists. About two thirds of the patients had received an immunomodulatory drug and 20 (38%) had had one or more surgical procedures for their RA. Anaemia was the commonest extra-articular manifestation, and although the other extra-articular features were uncommon, a variety of features had been detected during the course of the disease. Earlier studies on blacks in Africa suggested that RA was a mild disease; our findings, however, are in agreement with the more recent surveys, which suggest that severe disease is not uncommon.

Serum concentration of vitamin D metabolites in rheumatoid arthritis

One-hundred and two patients with rheumatoid arthritis (RA) were studied. They were divided into three groups according to treatment with gold salts, penicillamine or glucocorticoids. Blood samples were drawn between November and January and four different metabolites of vitamin D (25(OH)D3, 24,25 (OH)2D3, 25,26 (OH)2D and 1,25 (OH)2D) were measured and compared to values from normal subjects. The mean serum concentrations of 25(OH)D3 in all three patient groups were significantly lower than those of the controls (p less than 0.01-0.001). The mean serum concentrations of 24,25 (OH)2D3 and 25,26 (OH)2D were not significantly different from the control values, whereas 1,25 (OH)2D concentrations were significantly lower in the penicillamine and steroid groups (p less than 0.05-0.01). When patients were stratified according to functional classes, we found a significant inverse relation between serum concentrations of 25(OH) D3, 24,25(OH)2D3, 25,26(OH)2D and the functional class, but not between 1,25(OH)2D and the functional class. We conclude that the decreased serum 25(OH)D3 concentration found in patients with RA is likely to be caused by decreased exposure to sunlight due to decreased activity, and thus is a result of the disease rather than a pathogenetic factor. Whether the small decrease in serum 1,25(OH)2D is of clinical significance and related to the development of osteoporosis in patients with RA is probably doubtful.

Are disease duration and degree of functional impairment determinants of bone loss in rheumatoid arthritis?

One hundred and five patients with rheumatoid arthritis treated with a variety of antirheumatic drugs, excepting glucocorticoids, were stratified according to the degree of functional impairment (functional classes I to IV) and duration of the disease (0-3 years; 4-8 years; and greater than 8 years). The variables investigated were distal forearm bone mineral content (BMC), biochemical markers of bone formation: serum alkaline phosphatase and serum bone gamma-carboxyglutamic acid containing protein (BGP) and biochemical markers of bone resorption: fasting urinary calcium and fasting urinary hydroxyproline. Significant relationships were found between BMC and functional impairment and duration of the disease. Indices of bone formation and bone resorption rose with increasing functional impairment, particularly those of bone resorption. It is concluded that disability induces osteopenia in rheumatoid arthritis by increasing the bone turnover with a more marked increased in resorption than in the formation processes. The effect of the disease duration is merely that of adding more years of functional impairment.

Chronic active hepatitis and Behçet's syndrome

In a patient with Behcet's syndrome the finding of five times the normal level of serum transaminase accompanied by weakness may be correlated to the syndrome itself. We performed needle biopsy of the liver in our patient which showed piecemeal necrosis and portal lympho-monocytic infiltration extending into the lobule. It is interesting that HLA B5 and B27 antigens were present. Simultaneous occurrence of chronic active hepatitis and Behcet's syndrome may imply the same autoimmune pathogenesis, as we suggest in this work.

Primary Sjogren syndrome: clinical and immunopathologic features

Primary Sjogren syndrome is an autoimmune condition in which dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) result from lymphocytic infiltration of lacrimal and salivary glands. Clinical and laboratory features of 60 primary Sjogren syndrome patients seen at our clinic during the past three years are presented. These patients illustrate the wide spectrum of extraglandular features that may occur as a result of lymphoid infiltration of lung, kidney, skin, stomach, liver, and muscle. They further emphasize the difficulty in classifying a patient as primary or secondary Sjogren syndrome (ie, sicca symptoms associated with systemic lupus erythematosus, rheumatoid arthritis, or scleroderma), particularly early in the disease course. As an initial step in understanding the pathogenesis, the lymphocytes that infiltrate the salivary glands and lymph nodes were characterized by using monoclonal antibodies that recognize distinct lymphocyte subsets and by using in vitro functional assays. These studies have demonstrated that affected tissues have infiltrates of T cells with helper/inducer activity and with a high frequency of "activation antigens." The immunohistologic techniques are useful in differentiating "benign" and "pseudolymphoma" lesions (both due predominantly to T cells) from non-Hodgkin lymphoma (usually due to B-cell infiltrates). Although there is no "cure" for primary Sjogren syndrome patient's symptoms may be significantly improved by measures aimed at prevention of ocular and dental complications and by the recognition of extraglandular features that may be amenable to specific treatment.

Prevalence of decreased bone mass in rheumatoid arthritis. Relation to anti-inflammatory treatment

The bone mineral content (BMC) in both forearms (highly correlated to total body calcium) was measured by photon absorptiometry in a representative sample of rheumatoid arthritis outpatients comprising 129 patients treated with either gold salts (n = 29), penicillamine (n = 61), prednisone (n = 24), or other anti-RA drugs (n = 15). The mean BMC value was 84% of normal (p less than 0.001) with the lowest mean value in the group treated with prednisone (73% of normal). The patients as a group had hypocalcaemia (p less than 0.001), raised serum alkaline phosphatase (p less than 0.001), and normal urinary excretion rates of calcium and hydroxyproline. These results indicate that RA patients have disturbances in their calcium and bone metabolism.

Hepatotoxic effects of anti-rheumatic drugs in cultured rat hepatocytes

Drug-induced liver injury has been suggested as a possible mechanism for the liver damage in rheumatic diseases. To evaluate the role of direct toxic action of drugs on hepatocytes, the effects of salicylate, chloroquine, prednisolone and indomethacin on LDH leakage from cultured rat hepatocytes were studied. Exposure for 24 h to the first two drugs induced liver damage, as reflected by LDH release, at concentrations 2-10 times as high as the therapeutic plasma levels in humans. Indomethacin and prednisolone at concentrations approx 50-100-fold higher than the therapeutic plasma levels, were not toxic to cultured hepatocytes. The data suggest that direct a toxic effect on hepatocytes is one possible mechanism of hepatotoxicity for salicylate and chloroquine, especially since the exposure time is much longer in humans than in the experimental model used here.

Elevated levels of smooth muscle autoantibodies in patients with acromegaly

Screening of sera from patients with central nervous system (CNS) tumors for serum antibodies to tumor and normal tissue antigens revealed that the sera from a significant percentage of patients with pituitary adenoma demonstrated reactivity for smooth muscle antibodies (SMA) at a serum titer (1/25) at which other CNS tumors are devoid of this reaction. The sera were assessed by an indirect immunofluorescent antibody assay on fresh cryostat sections of rat kidney, liver, diaphragm, and stomach tissue. Absorption of SMA-positive sera with extracts containing smooth muscle tissue abolished the reaction. The overall incidence of SMA among patients harboring pituitary tumors was 30% (12/40). Assessment of the functional types of the tumor revealed a distinct predilection for such findings among patients with clinical acromegaly. Among patients with hypersecretion of growth hormone (CA) 90% (9/10) have SMA (both IgG and IgM type) whereas SMA was positive in only 10% (3/30) of corresponding group of patients with pituitary tumors resulting in hypercortisolemia or those that did not result in a hyperfunctional endocrine state.

Liver disease in Felty's syndrome

Eighteen patients with Felty's syndrome were examined prospectively for the presence of hepatic abnormalities. Twelve patients had abnormal liver histologic features: five with nodular regenerative hyperplasia and seven with portal fibrosis or abnormal lobular architecture. Only seven of the 12 had abnormal liver chemistry results. Four of the 12 had portal hypertension, and three bled from esophageal varices compared with one of six with normal histologic features. When patients with normal and abnormal liver histologic findings were compared, there was no difference in clinical, serologic, or extra-articular manifestations between the two groups, although there was a tendency for the patients with abnormal findings to have a higher incidence of vasculopathy. All patients with Felty's syndrome should be screened for hepatic abnormalities and portal hypertension as they have an increased likelihood of bleeding from esophageal varices.

Serum gamma-glutamyltransferase and alkaline phosphatase in rheumatoid arthritis

Serum gamma-glutamyltransferase (GGT) and alkaline phosphatase (AP) were assayed in 98 consecutive patients with rheumatoid arthritis. Twenty-three patients had increased GGT activities and 45 an increased AP activity. Twelve patients showed an increase in both enzyme activities and AP isoenzyme studies were performed on seven of this group. In three subjects an increase in the bone isoenzyme was observed and in three others the increase in activity was attributed to the liver isoenzyme. The remaining patient, who probably suffered from coexistent primary biliary cirrhosis, showed an increase in both bone and liver isoenzymes. The liver involvement, suggested by the alkaline phosphatase isoenzyme results, was largely confirmed by the butanol extraction of GGT. The changes in these enzymes in this small series could not be related definitely to drug therapy. It is concluded that though increases in GGT and AP are common in rheumatoid arthritis, this does not necessarily indicate hepatic involvement. Further isoenzyme studies are needed to define the extent to which organs other than the liver bring about increases in these serum enzymes in rheumatoid disease.