Diagnostic value of bone marrow biopsy in patients with renal disease secondary to familial Mediterranean fever

Characteristics and course of patients with AA amyloidosis: single centre experience with 174 patients from Turkey

OBJECTIVES

This study aimed to evaluate the clinical, laboratory and genetic characteristics and outcomes of patients with AA amyloidosis.

METHODS

Patients followed up in a tertiary referral centre in Turkey with the diagnosis of inflammatory rheumatic diseases and immunohistologically proven AA amyloidosis were included in the study and retrospectively analysed.

RESULTS

Among 184 patients with the diagnosis of AA amyloidosis, 174 (83 female, 91 male) were included in the analysis. The most common cause of AA amyloidosis was FMF (78.7%), and 91% of FMF-AA amyloidosis patients were carrying the p.M694V variant (74.1% homozygous). AA amyloidosis was identified earlier in patients with homozygous or compound heterozygous MEFV exon 10 variants compared with the heterozygous patients (27, 30 and 41 years, respectively). Patients with an estimated glomerular filtration rate <60 ml/min at admission had a higher frequency of progression to end-stage renal disease (P < 0.001). The overall mortality rate was 15.3% and it increased gradually in association with the amyloid burden (10% in patients with renal, 15% in renal + gastrointestinal and 43% in those with additional cardiac involvement). Renal findings responded completely to treatment in 31% of the patients, a partial response was observed in 4%, a stable course in 23.6% and progression in 38.5%. Amyloid storm was identified in nine patients and was found to be associated with increased mortality within 1 year.

CONCLUSION

FMF patients still constitute the majority of AA amyloidosis patients in Turkey. The MEFV genotype and associated inflammatory load may affect the age of onset of AA amyloidosis, and earlier diagnosis and stricter follow-up and treatment may delay progression of the disease.

Bone marrow amyloid: a comprehensive analysis of 1,469 samples, including amyloid type, clinical features, and morphologic distribution

BACKGROUND

Bone marrow biopsy is common in patients suspected of having systemic AL amyloidosis. However, little is known about the incidence, morphology and clinical phenotype of non-AL amyloid types in bone marrow.

METHODS

We retrospectively identified N = 1469 bone marrow amyloid biopsies typed using a proteomics-based method between 2008-2020. Frequency of amyloid types (N = 1469), distribution of amyloid deposits (N = 139), and clinical phenotypes (N = 355), with particular emphasis on cardiac involvement, were assessed.

RESULTS

The amyloid types were: AL (N = 1172; 79.8%), ATTR (N = 240; 16.3%), AH (N = 38; 2.6%), AA (N = 17; 1.2%), and Aβ2M (N = 2; 0.1%). Although there were characteristic morphologic features, including periosteal soft tissue and/or vascular involvement in ATTR, interstitial vascular involvement in AA, and variable anatomic compartment involvement in AL, none were pathognomonic. Most patients with both an M-spike and cardiac involvement had AL amyloid in their BM, but in over 10% the amyloid type was ATTR. Compared to AL patients, ATTR patients had higher stage cardiac amyloidosis and lower overall survival, which was mainly due to advanced cardiac stage.

CONCLUSIONS

ATTR amyloid is common in bone marrow and its morphologic distribution overlaps with AL. Amyloid typing is critical as over 10% of patients with bone marrow amyloid, cardiac amyloidosis, and an M-spike have ATTR amyloidosis.

Is there a role for 18F-FDG PET-CT in Familial Mediterranean fever? A case report and overview of the literature

Familial Mediterranean Fever (FMF) is an autosomal recessive disorder that is characterised by recurrent attacks of fever and painful polyserositis mainly affecting the peritoneum, synovium and pleura that usually begins in childhood. Even though diagnostic criteria have been proposed, conclusive imaging findings or haematological markers for the diagnosis or follow-up of FMF are still lacking. In this case report we present the ¹⁸F-FDG PET-CT findings in a 55 year old female during an attack of FMF. We briefly discuss the added value of ¹⁸F-FDG PET-CT in the diagnosis and the work-up of FMF, which may open up new applications for ¹⁸F-FDG PET-CT in non-infectious inflammatory diseases.

The Pathology of Amyloidosis in Classification: A Review

BACKGROUND

The amyloidoses are a rare and heterogeneous group of disorders that are characterized by the deposition of abnormally folded proteins in tissues ultimately leading to organ damage. The deposits are mainly extracellular and are recognizable by their affinity for Congo red and their yellow-green birefringence under polarized light. Current classification of amyloid in medical practice is based on the amyloid protein type. To date, 36 proteins have been identified as being amyloidogenic in humans.

SUMMARY

in clinical practice, it is critical to distinguish between treatable versus non-treatable amyloidoses. Moreover, amyloidoses with a genetic component must be distinguished from the sporadic types and systemic amyloidoses must be distinguished from the localized forms. Among the systemic amyloidoses, AL continues to be the most common amyloid diagnosis in the developed world; other clinically significant types include AA, ALECT2, and ATTR. The latter is emerging as an underdiagnosed type in both the hereditary and wild-type setting. Other hereditary amyloidoses include AFib, several amyloidoses derived from apolipoproteins, AGel, ALys, etc. In a dialysis setting, systemic amyloid derived from β2 microglobulin (Aβ2M) should be considered, although a very rare hereditary variant has also been reported; several amyloidoses may be typically associated with aging and several iatrogenic types have also emerged. Determination of the amyloid protein type is imperative before specific therapy can be implemented and the current methods are briefly summarized. A brief overview of the target organ involvement by amyloid type is also included. Key Messages: (1) Early diagnosis of amyloidosis continues to pose a significant challenge and requires the participation of many clinical and laboratory specialties. (2) Determination of the protein type is imperative before specific therapy can be implemented. (3) While mass spectrometry has emerged as the preferred method of amyloid typing, careful application of immune methods is still clinically useful but caution and experience, as well as awareness of the limitations of each method, are necessary in their interpretation. (4) While the spectrum of amyloidoses continues to expand, it is critical to distinguish between those that are currently treatable versus those that are untreatable and avoid causing harm by inappropriate treatment.

Should the Reporting of Bone Marrow Positivity for Amyloid Be Revised? A Critical Assessment Based On 66 Biopsies From a Single Institution

CONTEXT.—

Amyloidoses are rare but heterogeneous disorders for which diagnosis is contingent upon the detection of deposits by Congo red stain and amyloid protein typing determines the treatment options.

OBJECTIVE.—

To address the reporting of bone marrow (BM) involvement by amyloid in relation to the spatial distribution of deposits and to explore whether the location of deposits may have clinical relevance.

DESIGN.—

We examined 66 BM biopsies positive for amyloid with regard to the location and type of amyloid, the percentage and clonality of plasma cells, other organ involvement, and relevant clinical information.

RESULTS.—

In 21 cases, amyloid deposits involved BM stroma, whereas 45 cases were nonstromal. All cases of stromal involvement were typed as AL amyloidosis (or presumed AL), whereas nonstromal involvement was associated with at least 3 types of amyloidosis: AL, ATTR, and AA. The initial diagnosis of amyloidosis was made in a BM specimen in 21 of 66 cases (31.8%). Plasma cells ranged from 1% to 80% (mean, 13.4%; median, 8%; <10% in 44 of 66 specimens [66.6%]) and were monoclonal in 58 of 66 cases (87.8%), and in 54 of 66 cases (81.8%) amyloid deposits were documented in at least one other organ.

CONCLUSIONS.—

This study demonstrates that there is significant heterogeneity in the spatial distribution of amyloid in BM biopsy specimens with medullary, extramedullary, purely vascular, or combined involvement. Whereas stromal deposits were associated exclusively with AL, nonstromal and purely vascular deposits were seen in at least 3 types of systemic amyloidosis (AL, AA, and ATTR). We discuss the reporting of BM biopsy tissue positivity for amyloid deposits.

Monoclonal gammopathy of renal significance (MGRS) increases the risk for progression to multiple myeloma: an observational study of 2935 MGUS patients

Purpose

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignancy preceding multiple myeloma (MM) or related disorders. In MGUS, renal impairment caused by deposition of the monoclonal immunoglobulins or free light-chains monoclonal gammopathy of renal significance (MGRS) is often associated with high morbidity and mortality. We analysed the prevalence of renal impairment, clinical features and the long-term outcome in 2935 patients with MGUS.

Methods

Between 1/2000 and 8/2016, 2935 adult patients with MGUS were identified in our database.

Results

In 44/2935 (1.5%) patients MGRS was diagnosed. In MGRS patients, significantly more progressions to MM were observed than in MGUS patients (18% vs. 3%; P<0.001). MGRS patients showed a higher risk for progression (HR 3.3 [1.5-7.4]) in the Cox model. Median time to progression was 23 years for MGUS and 18.8 years for MGRS patients. Corresponding progression rate was 8.8 [7.2-10.7] per 1000 patient-years (py) for MGUS patients and 30.6 [15.3–61] for the MGRS group. Risk for progression within the first year after diagnosis was 1% [0.6-1.4] in the MGUS group and 10% [4-29] among MGRS patients.

Conclusion

The significantly higher risk for progression to MM means MGRS patients should be monitored carefully and treated in a specialized centre.

A case of primary (AL) amyloidosis with predominantly vascular amyloid deposition in the kidney

We report a 70-year-old man with primary (AL) amyloidosis with predominantly vascular deposition of amyloid diagnosed by renal biopsy, who was successfully treated using two chemotherapy regimens. There was rapid elevation of the serum creatinine level without remarkable proteinuria or hematuria. Renal histological examination showed some thickened arterial walls with amyloid fibril accumulation, and only a small amount of amyloid deposition in the glomeruli. Immunohistochemical examination was positive for anti-kappa staining. Serum immunoelectrophoresis and immunofixation testing did not show monoclonal proteins, and urine immunoelectrophoresis did not show Bence-Jones proteins. Serum free light chain (FLC) analysis showed that the serum FLC level and FLC kappa/lambda ratio were abnormally high for his renal function. He received two courses of VAD (vincristine, doxorubicin, and dexamethasone), followed by BD (bortezomib and dexamethasone), resulting in a hematologic partial response. Renal amyloidosis with vascular-limited amyloid deposition has few urinary findings. Early diagnosis of this condition is challenging, because kidney biopsies are not usually performed in patients without significant urinary findings. We suggest several currently available methods of achieving earlier detection of this condition.

Familial Mediterranean fever: An updated review

Familial Mediterranean Fever (FMF) is a hereditary autoinflammatory disorder characterised by acute attacks of fever and serosal inflammation. FMF primarily affects Jewish, Armenian, Turkish, and Arab populations. The disease is accompanied by a marked decrease in quality of life due to the effects of attacks and subclinical inflammation in the attack-free periods. Untreated or inadequately treated patients run the risk of amyloidosis, which is an important cause of morbidity and mortality. In this review, the current information available on FMF is summarised.

Familial mediterranean fever: a fascinating model of inherited autoinflammatory disorder

BACKGROUND

Familial Mediterranean fever (FMF) is a rare inherited autosomal recessive autoinflammatory disorder characterized by recurrent and self-limited episodes of fever and painful serositis, lasting 1-3 days. FMF occurs almost exclusively among ethnic groups of the Mediterranean basin, although cases have also been found in Japan and Korean populations. Diagnosis is based on clinical features, response to colchicine and genetic analysis. Novel drugs are emerging, allowing better management of colchicine-resistant/colchicine-intolerant patients. This review aims to attract the attention of the readers on differential diagnosis and management of patients with FMF.

METHODS

The current state-of-the-art on FMF is outlined, with respect to epidemiological, genetic, pathophysiological and therapeutic characteristics, based on critical analysis of solid scientific literature.

RESULTS

FMF is more frequent than it was thought before. The phenotypic expression of M694V is more severe than that of V726A. Patients with M694V/M694V homozygosity are exposed to a higher risk of developing renal amyloidosis, arthritis, dermatologic and oral lesions, higher fever and more frequent painful attacks. Life-long therapy with colchicine (1·0-2·4 mg/day) is effective and safe to prevent recurrent attacks and renal amyloidosis and to reverse proteinuria. In nonresponder patients, alternative novel approaches include interleukin-1 receptor antagonist anakinra and the interleukin-1 decoy receptor rilonacept.

CONCLUSIONS

The prognosis of FMF is normal if AA amyloidosis is prevented. Colchicine remains the first-line therapy to treat pain and prevent amyloidosis. A follow-up should include clinical evaluation, therapeutic adjustments, measurement of serum amyloid A and proteinuria.

Novel therapeutics for the treatment of familial Mediterranean fever: from colchicine to biologics

Familial Mediterranean fever (FMF), an inherited autosomal recessive disorder, is characterized by sporadic, paroxysmal attacks of fever and serosal inflammation, lasting 1-3 days. Patients may develop renal amyloidosis, arthritis, serositis, and skin and oral lesions. Diagnosis is based on clinical features, response to treatment with colchicine, and genetic analysis. Colchicine prevents attacks and renal amyloidosis, in addition to reversing proteinuria. Nonresponders may receive novel therapy, including interleukin (IL)-1 receptor antagonists and IL-1 decoy receptor. Recently, new options have been considered.

Renal amyloidosis in children

Renal amyloidosis is a detrimental disease caused by the deposition of amyloid fibrils. A child with renal amyloidosis may present with proteinuria or nephrotic syndrome. Chronic renal failure may follow. Amyloid fibrils may deposit in other organs as well. The diagnosis is through the typical appearance on histopathology. Although chronic infections and chronic inflammatory diseases used to be the causes of secondary amyloidosis in children, the most frequent cause is now autoinflammatory diseases. Among this group of diseases, the most frequent one throughout the world is familial Mediterranean fever (FMF). FMF is typically characterized by attacks of clinical inflammation in the form of fever and serositis and high acute-phase reactants. Persisting inflammation in inadequately treated disease is associated with the development of secondary amyloidosis. The main treatment is colchicine. A number of other monogenic autoinflammatory diseases have also been identified. Among them cryopyrin-associated periodic syndrome (CAPS) is outstanding with its clinical features and the predilection to develop secondary amyloidosis in untreated cases. The treatment of secondary amyloidosis mainly depends on the treatment of the disease. However, a number of new treatments for amyloid per se are in the pipeline.

A microscopic study of kidney tissue in familial mediterranean fever patients

Familial Mediterranean Fever (FMF) is an autosomal recessive hereditary disease leading mostly to renal failure and nephrotic syndrome. The ultrastructure of kidney has not been fully investigated in FMF associated renal disease. The aim of this study is to provide further evidence on the ultrastructure of kidney in patients with FMF who suffer from renal disease. Renal biopsies obtained from two patients who were diagnosed with FMF renal disease complications were examined. Examination of renal tissue by light and electron microscopy identified degenerations both in tubules and the filtration barrier. Foot processes were partly effaced. Amorphous material was found in thickened glomerular basement membranes. Fibrous material deposits in thick Bowman's capsule wall were also seen. Finally, degeneration in the form of folding of plasma membrane and vacuolization as well as fusion in mitochondria cristae, was observed. Accumulation of tissue remnants in the lumen was also found in tubules.

Adrenal axis functions in patients with familial Mediterranean fever

OBJECTIVE

Familial Mediterranean fever (FMF) is a hereditary disease characterized by recurrent attacks of fever with peritonitis, arthritis, pleuritis or erysipelas-like rash. It is unclear what effects of FMF itself on endocrine system and hormones are. None of the FMF patients without amyloidosis have been reported to have any endocrine disorders, except those who developed colchicine-induced diabetes insipidus. There is a large body of evidence to show that cytokines (IL-1, IL-6 and TNF-alpha) activate the hypothalamic-pituitary-adrenal (HPA) axis. We have designated this study to investigate the HPA axis in FMF patients without amyloidosis.

METHODS

Twenty-one patients with FMF were included. ACTH stimulation test was performed on the healthy subjects and during attack period in the patients. In the patient group, same test was repeated during remission period.

RESULTS

Peak cortisol levels were significantly higher in the attack period than those in the remission period of patients (p<0.05).

CONCLUSION

The cytokines play a role on the activation of the HPA axis; we thought the axis would be affected in this disease. The response of cortisol to 250 mug ACTH was significant in attack period when compared with remission period. This result reveals that HPA axis is more activated in an FMF attack. Previous studies suggest that the adrenal hormones increase in acute inflammatory events, and eventually, the changes on these hormones are related to TNF and IL-6 levels. During the FMF attack, HPA axis may be stimulated by cytokines. It seems that HPA axis is regulated normally in FMF patients.

[From familial Mediterranean fever to amyloidosis]

The progression of familial Mediterranean fever is marked by the recurrence, at varying intervals, of acute flares that regress spontaneously. Prognosis, which depends on the occurrence of amyloidosis, has been transformed by colchicine treatment. Incidence of amyloidosis is higher in certain ethnic groups (Jews from North Africa, Turks) and depends on by the specific MEFV mutation. Amyloid is composed of clusters of protein strands identical to the AA protein of secondary amyloidosis and infiltrates the walls of all arterioles except those of the central nervous system. The earliest and most consistent localization is in the kidney, where it develops over several years and in 4 stages--preclinical (latency), proteinuric, nephrotic and uremic--before concluding in end-state renal failure. Before the advent of colchicine, dialysis and transplantation, only renal amyloidosis caused clinical manifestations and lethal complications; any amyloidosis at any other sites remained latent. Prolonged survival with hemodialysis and kidney transplantation now leaves time for manifestation of these other localizations, such as infiltration into the intestines causing malabsorption, or potentially lethal cardiac lesions. Treatment of familial Mediterranean fever is based on the continuous administration of colchicine, which at the average dose of 1 to 2 mg per day can prevent flares or at least reduce their frequency or intensity. Systematic use of colchicine also prevents the onset of amyloidosis, even in the rare cases where it cannot prevent flares. These data fully justify the systematic use of colchicine for continuous prophylactic treatment from diagnosis and even after kidney transplantation, to prevent recurrence of the grafted kidney or extension to other organs. The curative efficacy of colchicine on flares is debatable, although several studies report positive results against progression of early amyloidosis.

From scleredema to AL amyloidosis: disease progression or coincidence? Review of the literature

Scleredema (also called scleredema of Buschke) is a fibromucinous connective tissue disorder of unknown cause that belongs to a group of scleroderma-like disorders. We report the case of a 64-year-old lady with long-standing scleredema, associated with a paraprotein, and progressing to multiple myeloma and AL amyloidosis. The relationship of scleredema with paraprotein and multiple myeloma is well established, but only two cases of scleredema associated with amyloidosis have been reported to date. We suggest that amyloidosis may be underdiagnosed in patients with scleredema and paraproteinaemia. Features attributed to extracutaneous manifestations of scleredema could represent systemic amyloidosis. We review published reports of scleredema associated with paraprotein and discuss the difficulties in the differential diagnosis of scleroderma-like disorders. We discuss the diagnosis of plasma cell dyscrasias and amyloidosis and their relevance in rheumatology practice.

Bone marrow amyloidosis with erythropoietin-resistant anemia in a patient undergoing chronic hemodialysis treatment

The resistance to erythropoietin, which is used to treat normochromic, normocytic anemia in chronic renal failure, can develop in patients with conditions such as iron deficiency, aluminum toxicity, hyperparathyroidism, chronic inflammatory diseases, and primary hematological disorders. We found amyloidosis in the bone marrow of a woman without any other etiology for erythropoietin resistance who was undergoing chronic hemodialysis. Her anemia did not improve, despite 6 months of erythropoietin therapy. Bone marrow amyloidosis was found to be the reason for erythropoietin-resistant anemia in our patient with chronic renal failure and renal anemia. We present the case of bone marrow amyloidosis because it is a very rare cause of erythropoietin resistance.

Familial Mediterranean fever at the millennium. Clinical spectrum, ancient mutations, and a survey of 100 American referrals to the National Institutes of Health

Regarded as the most common and best understood of the hereditary periodic fever syndromes, familial Mediterranean fever (FMF) is a recessively inherited disease of episodic fever with some combination of severe abdominal pain, pleurisy, arthritis, and a characteristic ankle rash. The flares typically last for up to 3 days at a time, and most patients are completely asymptomatic between attacks; if untreated with prophylactic colchicine, some patients later develop amyloidosis and renal failure. The recent cloning of the FMF gene on the short arm of chromosome 16p, and the subsequent finding that its tissue expression is limited to granulocytes, has helped to explain the dramatic accumulation of neutrophils at the symptomatic serosal sites; the wild-type gene likely acts as an upregulator of an anti-inflammatory molecule or as a downregulator of a pro-inflammatory molecule. For nearly half a century, FMF was thought to cluster primarily in non-Ashkenazi Jews, Arabs, Armenians, and Turks, although the screening of the 8 known mutations in an American cohort has identified substantial numbers of people from the Ashkenazi Jewish and Italian populations in the United States who also have this disease. Nevertheless, the symptoms often go unrecognized and patients remain undiagnosed for years, not receiving the highly efficacious colchicine therapy; their histories often include multiple laparotomies, laparoscopies, and psychiatric evaluations. The combinations of clinical manifestations among FMF patients are quite heterogeneous, but our American cohort did not establish any connections between individual mutations and specific clinical pictures--as is seen in other diseases like cystic fibrosis, in which distinct genotypes target certain organ systems. Specifically, the data from our American series are insufficient to evaluate the hypothesis that the M694V/M694V genotype confers a more severe phenotype, or increases the risk of amyloidosis; but both our data and the recent literature (160) indicate that amyloidosis can occur in FMF patients with only 1 copy, or no copies, of the M694V mutation. It appears that specific MEFV mutations are probably not the sole determinants of phenotype, and that unknown environmental factors or modifying genes act as accomplices in this disease. Although we hope the discovery of the FMF gene will allow the diagnosis of FMF to become genetically accurate, the reality is that both clinical and genetic tools must still be used together unless mutations are identified on both of a patient's chromosomes. Physicians should be careful not to rule out the diagnosis in patients of high-risk ethnic backgrounds just because of atypical clinical features, as our data indicate that MEFV mutations are sometimes demonstrable in such patients. At the same time, physicians cannot yet rely solely on a genetic diagnosis because we have not yet identified a sufficient spectrum of mutations, and it is not currently feasible to examine every patient's full DNA sequence for the entire gene; screening an ethnically consistent and clinically positive patient for the 8 known mutations frequently identifies a mutation on only 1 chromosome, and genetic analysis of other classic cases will often reveal none of the 8 mutations. Still, our data suggest that ethnic background is an important predictor of finding 1 of the presently known mutations, and the knowledge of ancestries atypical for FMF can suggest the diagnosis of other hereditary periodic fever syndromes. As the list of FMF-associated MEFV mutations is expanded, and/or new sequencing technologies permit more rapid screening, the value and interpretation of genetic testing for FMF will become more straightforward. Moreover, as the pathophysiology of this disorder becomes less of a hypothesis and more of an understood entity, it is likely that treatment options will broaden beyond the use of daily prophylactic colchicine. (ABSTRACT TRUNCATED)

Peritoneal mesothelioma in recurrent familial peritonitis

A 39-year-old man had a 2-year history of fatigue, weight loss, drug-resistant ascites, and decreased intestinal motility. During adolescence he began to suffer frequent episodes of acute benign peritonitis that spontaneously subsided at age 35. The fact that his younger brother was taking colchicine for the same symptoms led us to diagnose familial Mediterranean fever (FMF). The medical workup revealed uniform thickening of the intestinal wall with no signs of amyloidosis. Exploratory laparotomy revealed diffuse peritoneal mesothelioma that proved to be unresponsive to chemotherapy. There was no history of asbestos exposure. It is probable that the chronic peritoneal inflammation was responsible for the development of this tumor, although in almost all cases of FMF this phenomenon causes only limited peritoneal fibrosis or, less commonly, encapsulating peritonitis. A computerized search of the literature indicates that this is the second report of peritoneal mesothelioma associated with FMF.

The changing face of familial Mediterranean fever

Familial Mediterranean fever (FMF) is a genetic disease characterized by painful febrile "attacks" of serositis and the development of amyloidosis. Although FMF has been extensively studied and described, new data have accumulated during the last decade. This report gives an update, focusing specifically on (1) newly characterized manifestations, such as acute scrotal "attacks," protracted febrile myalgia, and spondyloarthropathy; (2) progress made in the diagnosis and treatment of FMF-amyloidosis; (3) experience acquired with colchicine, establishing its safety in common practice, childhood, conception, and pregnancy; (4) colchicine's role in the prevention and treatment of FMF-amyloidosis; (5) new laboratory findings; and (6) new considerations in the differential diagnosis. The most important achievement in recent years, however, is the mapping of the FMF susceptibility gene to chromosome 16p, a finding that raises hopes for prompt cloning of the gene and elucidation of the mechanisms involved in FMF expression.

The classification of amyloid deposits in clinicopathological practice

A series of 104 biopsy cases with histopathological proof of amyloid, submitted to our department of pathology over the last 19 years, were re-examined. The survey investigated the medical indication for surgery, the origin and quality of the biopsy and the clinical information as documented on the request form for histopathological examination and in hospital records. Amyloid deposits were classified using antisera directed against five major amyloid fibril proteins, i.e. AA, ATTR, A lambda, A kappa and A beta 2M and optimal conditions were sought for the reliable and early characterization of amyloid disease in clinicopathological practice. This survey revealed that 98% of the biopsy cases already suffered from a disease which was either a cause or a result of amyloidosis. In only 2% of the biopsy cases was amyloidosis detected without any clinical indication. Immunohistochemical classification of the amyloid deposits and comparison with hospital records demonstrated diagnostic pitfalls such as immunostaining of amyloid by two or more antibodies recognizing different fibril proteins, and disagreement between immunohistochemical typing of amyloid and the initial clinical diagnosis. Based on these observations we assume that the characterization of amyloid disease and its biological significance is impossible in clinicopathological practice without clinical information or without immunohistochemical classification of the fibril protein in biopsy specimens. Different aspects of histopathological detection of AA- and AL-amyloidosis are discussed.