Search

Objective: Low molecular mass hyaluronan causes inflammatory processes and can act as a pro-inflammatory cytokine in skin and other sites of activity in psoriatic arthritis (PsA). This study investigated whether the molecular mass distribution of hyaluronan (HA) in skin and the quantity of circulating HA are related to the clinical inflammatory picture in PsA with active disease and to the effect of treatment with anti-tumour necrosis factor-α (anti-TNF-α) adalimumab. Methods: Twenty patients with TNF-α-naïve active polyarticular PsA were included in this prospective clinical trial of treatment with 40 mg s.c. adalimumab according to standard procedure. Clinical activity, patients’ assessments, and skin biopsies were captured at inclusion and at the 12 week follow-up. Ten healthy individuals were recruited for comparison of HA analyses. Histochemistry of skin inflammation, serum HA, and molecular mass of HA were determined. Results: Overall improvements in clinical parameters were observed. Eight of 18 patients reached minimum disease activity after 12 weeks and disease activity was significantly reduced (p

Severe coronavirus disease 2019 (Covid-19) is characterized by inflammation of the lungs with increasing respiratory impairment. In fatal Covid-19, lungs at autopsy have been filled with a clear liquid jelly. However, the nature of this finding has not yet been determined. The aim of the study was to demonstrate whether the lungs of fatal Covid-19 contain hyaluronan, as it is associated with inflammation and acute respiratory distress syndrome (ARDS) and may have the appearance of liquid jelly. Lung tissue obtained at autopsy from three deceased Covid-19 patients was processed for hyaluronan histochemistry using a direct staining method and compared with staining in normal lung tissue. Stainings confirmed that hyaluronan is obstructing alveoli with presence in exudate and plugs, as well as in thickened perialveolar interstitium. In contrast, normal lungs only showed hyaluronan in intact alveolar walls and perivascular tissue. This is the first study to confirm prominent hyaluronan exudates in the alveolar spaces of Covid-19 lungs, supporting the notion that the macromolecule is involved in ARDS caused by SARS-CoV-2. The present finding may open up new treatment options in severe Covid-19, aiming at reducing the presence and production of hyaluronan in the lungs.

Scar tissues were collected from patients with keloids, hypertrophic scars and mature scars. Normal skin was obtained from healthy individuals. Clinical attributes were used to select which tissue to obtain but the distribution of the specific hyaluronan (HA) staining was then used for the definite classification of the various scar types. Light microscopic and ultrastructural analyses were performed with an HA-binding probe, antibodies for collagen I and III and staining for mast cells. Ultrastructural studies of keloids revealed an altered collagen structure in the dermal layers, with an abundance of collagen fibres of similar diameter in both the reticular dermis (RD) and the papillary dermis (PD) compared to normal skin. Furthermore, the keloids displayed epidermal changes, which involved the basement membrane (BM), with fewer hemidesmosomes and an altered shape of desmosomes in the entire enlarged spinous layer. The frequency of mast cells found in keloids was lower than in other scar tissues and normal skin. These alterations in epidermis could influence the hydrodynamic and cell regulatory properties of the wounded skin with impaired function and insufficient regulative capacity to hinder the ever-growing collagen tissue that is characteristic for keloids.

Introduction. The hypertrophic cardiomyopathy (HCM) disease process is not only limited to cardiomyocyte abnormalities but also engages the extracellular matrix. Hyaluronan (HA) and its receptor CD44 are involved in cellular growth and tissue proliferation but have so far been less studied in myocardial hypertrophy. In HCM, collagens are abundant but their histological distribution and relation to hyaluronan have not been described.Material and Methods. Myocardial specimens from 5 patients with symptomatic left ventricular tract obstruction undergoing myectomy due to HCM were processed for histochemistry and immunohistochemistry.Results. HA staining was more intense in HCM patients. The histological distribution of HA was the same in patients and controls, that is, interstitial staining including the space between cardiomyocytes, in fibrous septa, and in the adventitia of intramyocardial blood vessels. CD44 was not detected in the myocardium of patients or controls. Collagen I showed the same general localisation as HA but detailed distribution differed.Conclusions. This is the first study that describes the distribution of hyaluronan in human HCM. HA staining is more intense in HCM patients but without coexpression of its receptor CD44, at least not in the chronic phase of HCM. HA and collagen I have the same localisation.

Psoriatic arthritis is a chronic systemic disease in which patients develop persistent inflammation of the skin and joints, leading to disability and joint damage. The extracellular component hyaluronan (HA) plays an important role in regulatory processes such as inflammation, wound healing and tumour progression. At any site of inflammation HA can be depolymerized to low-molecular weight fragments, which, in turn, induce an array of inflammatory mediators that can lead to chronic inflammation. This study describes the serum concentration and dermal distribution of HA, its receptor CD44 and the metalloproteinases 3 and 9 in skin biopsies from patients with different types of psoriatic arthritis. Fifty-one patients with psoriatic arthritis were included in the study and classified as oligo- or poly-arthritic PsA with and without treatment. Biopsies were obtained from both involved and non-involved skin and compared with biopsies from healthy individuals. Serum HA was analysed for estimation of the total turnover of HA. The main findings were an overall redistribution of HA in both involved and non-involved psoriatic skin and an epidermal imbalance between HA and CD44. The structurally and functionally important basement membrane zone was found to be disintegrated and devoid of HA irrespective of the type of articular involvement, treatment or skin affection.

Objectives To perform a multicentre study to evaluate the performance of the colorimetric redox indicator (CRI) assay and to establish the MICs and critical concentrations of rifampicin, isoniazid, ofloxacin, kanamycin and capreomycin. Methods The study was carried out in two phases. Phase I determined the MIC of each drug. Phase II established critical concentrations for the five drugs tested by the CRI assay compared with the conventional proportion method. Results Phase I: a strain was considered resistant by the CRI assay if the MIC was >/=0.5 mg/L for rifampicin, >/=0.25 mg/L for isoniazid, >/=4.0 mg/L for ofloxacin and >/=5.0 mg/L for kanamycin and capreomycin. Sensitivity was 99.1% for isoniazid and 100% for the other drugs and specificity was 97.9% for capreomycin and 100% for the other drugs. Phase II: the critical concentration was 0.5 mg/L for rifampicin, 0.25 mg/L for isoniazid, 2.0 mg/L for ofloxacin and 2.5 mg/L for kanamycin and capreomycin giving an overall accuracy of 98.4%, 96.6%, 96.7%, 98.3% and 90%, respectively. Conclusions Results demonstrate that the CRI assay is an accurate method for the rapid detection of XDR Mycobacterium tuberculosis. The CRI assay is faster than the conventional drug susceptibility testing method using solid medium, has the same turnaround time as the BACTEC MGIT 960 system, but is less expensive, and could be an adequate method for low-income countries.

Tuberculosis (TB) is an ancient disease, but not a disease of the past. The increasing prevalence of drug-resistant strains of Mycobacterium tuberculosis, the causative agent of TB, demands new measures to combat the situation. Rapid and accurate detection of the pathogen, and its drug susceptibility pattern, is essential for timely initiation of treatment, and ultimately, control of the disease. Molecular-based methods offer a great chance to improve detection of drug-resistant TB; however, their development and usage should be accompanied with a profound understanding of drug resistance mechanisms and circulating M. tuberculosis strains in specific settings, as otherwise, the usefulness of such tests may be limited. This review gives an overview of the history of TB treatment and drug resistance, drug resistance mechanisms for the most commonly used drugs and molecular methods designed to detect drug-resistant strains.

To study the hyaluronan occurrence in human vocal folds, with special regards to gender and smoking and to discuss the implications of findings.This is a descriptive/morphologic study.Sixteen cadaveric vocal folds from eight individuals between 58 and 90 years old (six women and two men) were removed and studied morphologically. Three of the individuals had been cigarette smokers. A direct method for hyaluronan histochemistry using a hyaluronan-binding protein probe (HABP) was used to visualize the polysaccharide. Five examiners performed an analysis of the intensities of hyaluronan staining, independently.We observed intense hyaluronan staining of the vocal folds of which those from women stained considerably stronger than those from men. Stratified squamous epithelium stained for hyaluronan in all sections, whereas respiratory epithelium only stained weakly or not at all. The highest accumulation of hyaluronan occurred subepithelially in the lamina propria, corresponding to Reinke's space. It was observed that vocal folds from smokers were more intensively stained than those from nonsmokers.Hyaluronan is found in all layers of the human vocal fold. Contradictory to earlier studies, hyaluronan was visualized in squamous epithelium, where it may function as an impact protector. The occurrence of hyaluronan in smokers may have implications in the development of vocal fold inflammation and tumor initiation as hyaluronan is an important molecule in these processes.

Tuberculosis (TB) remains a global health problem. The increasing prevalence of drug-resistant Mycobacterium tuberculosis, the causative agent of TB, demands new measures to combat the situation. Rapid and accurate diagnosis of the pathogen and its drug susceptibility pattern is essential for timely initiation of optimal treatment, and, ultimately, control of the disease. We have developed a molecular method for detection of first- and second-line drug resistance in M. tuberculosis by Pyrosequencing(®). The method consists of seven Pyrosequencing assays for the detection of mutations in the genes or promoter regions, which are most commonly responsible for resistance to the drugs rifampicin, isoniazid, ethambutol, amikacin, kanamycin, capreomycin, and fluoroquinolones. The method was validated on clinical isolates and it was shown that the sensitivity and specificity of the method were comparable to those of Sanger sequencing. In the protocol in this chapter we describe the steps necessary for setting up and performing Pyrosequencing for M. tuberculosis. The first part of the protocol describes the assay development and the second part of the protocol describes utilization of the method.

Acute myeloid leukemia (AML) is a clonal disorder characterized by abnormal proliferation of myeloid cell precursors. Research has mainly focused on the cellular events, but the bone marrow matrix has attracted minor interest. In this study bone marrow biopsies were obtained from 35 newly diagnosed AML patients. The bone marrows were analyzed regarding the occurrence and distribution of hyaluronan (HYA) and reticulin fibers (type III collagen). The bone marrow sections were analyzed histochemically and compared with bone marrows from 30 healthy controls. The HYA staining was significantly stronger in the AML patients compared with the controls. Only one patient demonstrated abnormal reticulin staining score, but in the group of patients with antecedent myelodysplastic syndrome (MDS), the reticulin staining score was significantly higher compared with the patients with de novo AML. There was a significant correlation between the HYA staining and reticulin staining scores in the AML patients as was seen in the control group.

Specimens of basal cell carcinomas collected from 28 patients were classified into three groups: superficial, nodular, and infiltrative, according to their microarchitecture. The specimens were then subjected to histological characterization by means of a biotinylated hyaluronan-binding probe (HABP). By using Ki-67 and PCNA the proliferative activity of the BCC tumours was evaluated with immunohistological techniques. In superficial BCC the tumour islands displayed moderate hyaluronan (HA) staining. Feeble proliferation, denoted by modest mitotic activity and weak Ki-67 and PCNA immunoreactivity, occurred within the tumour islands. The surrounding connective tissue resembled normal skin, and no differentiated tumour stroma was observed. In nodular BCC, the HA staining of the tumour strands was weak to moderate, denoting increased proliferative activity. The differentiated surrounding tumour stroma stained strongly for HA. Tumour islands of infiltrative BCC stained weakly to moderately to HA and evidenced intense proliferation. The intensely HA-stained tumour stroma ended abruptly and the adjacent areas were almost devoid of HA. This study showed that the proliferative activity of BCC cells is associated with increased expression of HA in the tumour stroma. Modification of tumour-associated connective tissue indicates a close relationship between the tumour cells and the adjacent matrix. In particular, in infiltrative BCC, such alterations include degeneration and possible modification and remodelling of the surrounding extracellular matrix. These processes involving areas of probable importance for tumour progression, should be considered when deciding the extent of intended surgical resection.

Bone marrow trephine biopsies from 30 healthy volunteers, 10 men and 20 women aged 18-60 yr were obtained for identification and localisation of hyaluronan (HYA). Fixation, decalcification and embedding were performed by two different methods, with identical results in both. For comparison bone marrow trephine biopsies from three patients with different haematological diseases and known fibrosis were studied. All bone marrow specimens were also stained for reticulin grading. HYA was found in the bone marrow specimens from healthy individuals in a pattern that was concordant with the reticulin staining, the common way of visualising bone marrow fibrosis. In bone marrow from the patients with known fibrosis the HYA and reticulin staining were both more intense and abundant. Interestingly, HYA was also found intracellularly in eosinophilic cells in normal bone marrow. HYA is a polysaccharide unique both in structural and biological properties, and in excess it may predict bone marrow fibrosis.

Objective. To investigate the production of type II collagen (CII) antibodies in the synovial fluid (SF) of rheumatoid arthritis (RA) patients, and to examine the HLA dependence of this local production. Methods. The ELISPOT method was used for enumerating anti-CII—reactive cells. Serologic tissue typing was performed. Results. Anti-CII—reactive cells were found in the SF of 16 of 31 patients, but not in any of the peripheral blood samples obtained in parallel. SF anti-CII antibody production showed no correlation with clinical parameters, but its frequency increased significantly with age. The IgG anti-CII response occurred exclusively in patients who were positive for HLA—DR4 and was significantly associated with DR4. Conclusion. Anti-CII production may be important in local immune complex formation. The indirect demonstration of a DR4-restricted T cell response to CII is an indication of a pathogenetic role of collagen autoimmunity in RA.

Our objective was to investigate whether the presence of a tumor increases hyaluronan (HA) levels in surrounding prostate tissues and whether this extratumoral HA influences tumor growth and outcome. From a series of 287 men diagnosed with prostate cancer at transurethral resection and followed up with watchful waiting, tissue microarrays were constructed, stained, and scored for HA. A high HA staining score in the tumor stroma or in nonmalignant prostate tissue stroma were both associated positively with higher Gleason score and larger tumor volume, and was associated with a poor outcome. HA staining score was not an independent marker for outcome (multivariate Cox, with Gleason score, tumor volume, stage, and HA variables). In an orthotopic rat prostate cancer model, hyaluronic acid synthase-1 mRNA levels and HA staining were increased in normal prostate tissue surrounding prostate cancer. Orthotopic prostate cancer growth was increased by intraprostatic injection of HA. In conclusion, cancer in the prostate apparently stimulates HA synthesis both in tumor stroma and in the surrounding normal tissue. This promoted tumor growth and was associated with an unfavorable outcome.

Myelofibrosis is commonly seen in patients with chronic myeloproliferative diseases and sometimes in myelodysplastic syndrome, acute leukaemia and lymphoproliferative diseases. The fibrotic process is evaluated by grading the amount of collagen deposited in the bone marrow interstitium. The established method to evaluate bone marrow fibrosis is staining for reticulin to visualise the collagen fibres. However, the extra cellular matrix does not only contain collagens but also other components, e.g. glycosaminoglycans of which hyaluronan is the most abundant. Hyaluronan is important for structural and cellular functions. Earlier studies have shown that there is a positive correlation between hyaluronan and reticulin staining in healthy volunteers and in patients with de novo acute myeloid leukaemia. In this study bone marrow biopsies from 43 patients with a malignant disease involving the bone marrow were compared with 18 patients with a malignant disease not involving the bone marrow. The intensity of hyaluronan grading was significantly higher in the patients with disease involving the bone marrow compared to the healthy controls but not compared to the patients without disease involving the bone marrow. The staining intensity of reticulin in the bone marrow was significantly higher in the patients with disease involving the bone marrow, compared to those without disease involving the bone marrow and to the controls. In all patients and the controls there was a correlation between hyaluronan and reticulin.

Anagrelide is a second-line option for reduction of thrombocythemia in patients with chronic myeloproliferative disorders (CMPDs). A multicenter, open, phase II study of anagrelide treatment in 60 patients during 2 yr was performed by the Swedish Myeloproliferative Disorder Study Group. Adequate bone marrow biopsies were obtained from 53 of the CMPD patients [36 essential thrombocythemia (ET), 16 polycythemia vera (PV), 1 chronic idiopathic myelofibrosis (CIMF)] before treatment and compared with biopsies from 30 healthy volunteers and 34 patients with acute myeloid leukemia (AML). Higher reticulin and hyaluronan (HYA) scores were found before anagrelide therapy in the CMPD patients than in the normal controls (p0.001 and p0.001, respectively) and AML patients (p0.001 and p = 0.011, respectively). At the end of the study 30 CMPD patients were still on anagrelide treatment and in 19 of these patients, all diagnosed as ET (n = 16) or PV (n = 3), pretreatment bone marrow biopsies were compared with follow-up samples. After 2 yr of anagrelide therapy the reticulin and HYA scores were significantly higher than before treatment (p = 0.02 and p = 0.002, respectively). The cellularity was significantly higher (p = 0.014), although the number of megakaryocytes did not change significantly. The increase of reticulin and HYA in the bone marrow after 2 yr of treatment with anagrelide indicated progression of fibrosis. Although anagrelide is a valuable drug for reduction of platelet levels, it seems unable to stop progression of bone marrow fibrosis and hypercellularity in ET and PV.

Glycosaminoglycans are important components of all extracellular matrices. One of the glycosaminoglycans is hyaluronan, which is ubiquitously distributed throughout the connective tissue. Hyaluronan is especially abundant in the skin, in which it is of both structural and functional importance. This study describes the localization and distribution of hyaluronan in the skin of healthy individuals and of 23 patients with insulin-dependent diabetes mellitus and various degrees of limited joint mobility. In normal skin, hyaluronan staining was seen in all layers but most prominently in the papillary dermis and the basement membrane zone. In the skin from diabetic patients with normal or only moderately restricted mobility of the hands (limited joint mobility grades 0 and 1), the distribution of hyaluronan was similar to that of normal skin. In the skin of patients with severe restriction in joint mobility (limited joint mobility grade 2) the staining pattern was significantly different with weak hyaluronan staining in the papillary dermis and the basement membrane zone almost devoid of hyaluronan. Moreover, an increased epidermal thickness in the latter patients was evident as well as a pronounced hyaluronan staining compared with normal epidermis.

Hyaluronan is a major component of synovial fluid. It is synthesized in the joint and partly degraded in joint capsule and partly carried by lymph to lymph nodes and the general circulation. During various joint disorders, especially inflammatory ones, the amount of hyaluronan in the joint and its turnover rate are increased leading to pathologically high serum levels of the polysaccharide. These levels are a complex function of synovitis mass and the physical activity of the patient. Intra-articular injection of hyaluronan has been used in the treatment of osteoarthritis. Although it results in a relief of pain, controlled clinical trials have not yet convincingly shown any beneficiary effects of the treatment.

Hyaluronan (HA) and aminoterminal propeptide of type III procollagen (PIIINP), two biochemical connective tissue markers, were determined in 76 patients with primary biliary cirrhosis (PBC). The HA and PIIINP concentrations were significantly increased compared with controls (P less than 0.001). Both HA and PIIINP levels correlated significantly with conventional liver-function tests. All patients with stage IV PBC showed increased concentrations of both these variables. However, HA was a better marker with regard to prediction of development of cirrhosis as well as prediction of symptoms. Furthermore, HA also showed a negative correlation with time of survival (P less than 0.05). The present data indicate that HA is a more sensitive marker of liver damage in PBC than PIIINP.

It has been suggested that a high level of hyaluronan (hyaluronic acid, HYA) in pleural fluid is an indicator of malignant mesothelioma. In 78 consecutive patients with pleural effusion of various causes the HYA concentration was measured in pleural fluid samples and in serum. Nine patients had malignant pleural mesothelioma, and in three of them the HYA level in pleural fluid was 100 mg/l or more. In 42 patients with effusions due to metastatic malignancy, the mean HYA in the pleural fluid was 75 mg/l, and in five the HYA level was above 100 mg/l. Cardiac insufficiency caused the effusion in 11 patients, of whom two had a level above 100 mg/l in pleural fluid. Four patients had a serologically confirmed viral infection and had HYA levels in pleural fluid of 8, 157, 335, and 554 mg/l, respectively. One patient had postinfectious effusion with an HYA level in pleural exudate of 748 mg/l, the highest in this investigation. Two patients had benign asbestos pleural effusions, and both had high pleural HYA levels (256 and 490 mg/l, respectively). The serum HYA values were much lower than in the pleural fluid, namely from 15 to 480 micrograms/l; the levels were independent of the levels in the pleural fluid. Thus, a high level of HYA in pleural fluid is not specific for mesothelioma but can occur in other malignant or benign diseases, and a low level does not exclude mesothelioma.

SummaryMiddle-ear effusions of the mucoid type were collected from 14 children with secretory otitis media and analysed by a sensitive assay for hyaluronic acid. The concentration of the polysaccharide varied between three and 42 μg/g. in different patients but was in the same range in effusion material taken from the two ears of the same patient. As the hyaluronic acid concentrations were high compared to the serum levels, the results indicate that the effusion material contains a component derived from connective tissue.

SUMMARY Hyaluronate concentrations were measured in suction blister fluid from blisters raised on the abdominal skin of 12 healthy control subjects, on unaffected skin of 14 patients with psoriasis, and on lesional skin from 12 of these patients. The concentrations of hyaluronate in blister fluid from the controls and from the uninvolved skin of patients with psoriasis were within the same range (2.9–10.5 and 2.4–7.8 mg/1, respectively). Six of the patients had active, widespread, untreated psoriasis and in these cases the hyaluronate concentration in blister fluid from lesional skin was greatly increased (24–30 mg/1). Patients with stable or regressing psoriasis had no significant increase in hyaluronate levels in the blister fluid from lesional skin compared with the controls (range 4.6–12.4 mg/1). Patients with active psoriasis had significantly higher serum hyaluronate concentrations than the controls and those with inactive psoriasis.

• Patients (n = 10) at the acute phase of farmer's lung were investigated with chest roentgenography, lung function tests, and bronchoalveolar lavage (BAL) fluid analysis (n = 9). They had diffuse interstitial lung infiltrates and a reduction of the diffusion capacity. The dominating recovered cell types during BAL were lymphocytes; and in two patients, granulocytes. A prominent increase in mast cell numbers was seen in all patients. After avoidance of contact with moldy plant material for four to ten weeks (n = 7), lung function started to improve; and the BAL cell counts, to decrease. At clinical remission six to 14 months later (n = 7), the chest roentgenogram was normal and the diffusion capacity was slightly subnormal. The BAL numbers of mast cells and lymphocytes had further decreased but still remained increased compared with those in the healthy controls. Parallel to the normalization of the lung function and the recovery of BAL fluid cells, the increased BAL fluid concentrations of hyaluronic acid and procollagen III peptide started to decrease. These potential markers of fibroblast activation were significantly related to the mast cell number, but not to the lymphocyte number. The study has demonstrated that pulmonary mastocytosis is a prominent finding in farmer's lung and is related to the disease activity. The observed relationship between pulmonary mastocytosis and biochemical signs of lung fibroblast activation is further evidence to support the hypothesis of a mast cell interaction with lung connective tissue. ( Arch Intern Med 1988;148:1362-1365)

Recent animal studies show that endothelial cells in liver sinusoids are the main site for removal of sodium hyaluronate from the circulation. Few data with respect to hyaluronate metabolism are available in man. Serum hyaluronate levels were measured in 119 patients with liver disease by a sensitive assay. The hyaluronate level was significantly increased in liver cirrhosis, in comparison with healthy controls and with patients with noncirrhotic liver disease. The results suggest a role for the human liver in elimination of hyaluronate from circulation. Quantification of serum hyaluronate may be a useful test of liver endothelial cell function.

To evaluate serum hyaluronate as a marker for progressive liver injury in patients with primary biliary cirrhosis, a longitudinal study including 48 patients was conducted with a mean follow-up time of 40 months. The patients were examined every 6 months with a standardized set of conventional liver function tests, and a liver biopsy was performed every year. The hyaluronate concentration correlated significantly (p less than 0.001) with albumin, t1/2 galactose tolerance test, bilirubin and prothrombin time but not to serum variables reflecting inflammatory activity. Furthermore, there was a close correlation between serum hyaluronate levels and histopathological changes in the liver. The hyaluronate concentration increased significantly over time in all clinical stages of primary biliary cirrhosis (p less than 0.01), whereas the conventional liver function tests only changed in the advanced cases. The present data indicate that serum hyaluronate may be a sensitive marker for progressive liver damage in primary biliary cirrhosis. Serial determinations of hyaluronate are therefore of potential value for monitoring liver function during clinical management of the condition.

Hyaluronate and type III procollagen propeptide were assayed in bronchoalveolar lavage (BAL) fluids from patients with sarcoidosis. Levels were significantly elevated suggesting increased rates of synthesis of these connective tissue components in the lung. They were strongly related to each other (p less than 0.001) favoring the idea of a common cellular origin, as a suggestion activated fibroblasts. There was a significant inverse correlation (p less than 0.001) between lavage hyaluronate or procollagen propeptide and the clinical severity of the disease process defined by lung volume, diffusion capacity and pulmonary radiological findings. Correlation of clinical findings with lavage cell profiles was poor except for recovered mast cells (p less than 0.001). Lavage mast cell counts were also closely associated with BAL fluid hyaluronate and procollagen peptide (p less than 0.001). These findings may reflect a link between the mast cell, the activation of fibroblasts, and the progress of connective tissue changes in sarcoid lung.

The variation of the serum concentration of hyaluronan during the day and between days has been investigated. In a group of healthy volunteers, the mean hyaluronan level was very stable over time except for a moderate but significant elevation after rising from bed in the morning. Patients with rheumatoid arthritis showed markedly increased hyaluronan concentrations 0.5-2 h after leaving bed. Patients with primary biliary cirrhosis exhibited high and rather constant levels during the day. A reference group of hospitalized patients with other diseases did not show any diurnal variation. The best reproducibility in hyaluronan determinations is obtained if specimens are taken before the subjects rise from bed or a few hours later, i.e. after the morning elevation of serum hyaluronan has subsided. In rheumatoid arthritis valuable information can be obtained by repeated sampling during the morning hours.

Serum concentrations of the aminoterminal propeptide of type III procollagen and of the 7S domain of type IV collagen, presumed to reflect fibrotic activity in liver tissue, and of the glycosamonoglycan hyaluronan, were obtained from 40 alcohol abusers, at the time of liver biopsy. The serological results were related to morphological findings in liver tissue, i.e. no fibrosis, fibrosis without cirrhosis, micronodular cirrhosis and macronodular cirrhosis, and to ultrastructural indications of perisinusoidal fibrosis in the acinar zone 3. All patients with fibrosis and cirrhosis on light microscopy had elevated serum levels of the type III procollagen peptide as well as of the 7S domain of type IV collagen. However, due to a considerable overlap between the groups, no relations could be demonstrated to the severity of the fibrosis, supporting the assumption that these serological markers reflect the current fibrotic activity and not the amount of fibrotic tissue previously deposited. Among patients without fibrosis on light microscopy, a relation between the propeptide levels and ultrastructural perisinusoidal zone 3 fibrosis was observed, suggesting that type III procollagen peptide may be valuable in detecting very early liver fibrosis. A positive correlation was demonstrated between the serum concentrations of type III procollagen peptide and hyaluronan. As hyaluronan is degraded in the liver endothelial cells, it is suggested that the liver is involved, not only in the synthesis, but also in the degradation of the propeptide.