Alkylating cytostatic treatment in renal amyloidosis secondary to rheumatic disease

Chronic kidney disease in rheumatoid arthritis patients: prevalence, risks factors, histopathological variants

The present review is focused on risk factors of chronic kidney disease in rheumatoid arthritis (RA). According to recent data, the chronic kidney disease (CKD) in RA patients is more often than at patients without RA. It is closely associated with risk of cardiovascular disease and high mortality. Besides of general population risk factors of CKD, the activity of the disease is independent predictors of reduction in glomerular filtration rate less than 60 ml/min/1.73 m2. In the review, histopathological variants and mechanisms of CKD on basis of international experience are also considered. Suppression of inflammation by basic therapy of RA and biological therapy have changed outcomes RA, prevalence, and structure of kidney involvement in recent years.

Renal involvement in AA amyloidosis: clinical outcomes and survival

BACKGROUND

The natural history of AA amyloidosis is typically progressive, leading to multiple organ failure and death. We analyzed the etiology as well as clinical and laboratory features of patients with biopsy-proven AA amyloidosis and evaluated the ultimate outcome.

METHODS

Seventy-three patients (24 female; mean age 41.85±15.89 years) were analyzed retrospectively. Demographic, clinical and laboratory features were studied and the outcome was assessed.

RESULTS

Familial Mediterranean Fever and tuberculosis were the most frequent causes of amyloidosis. Mean serum creatinine and proteinuria at diagnosis were 4.65±4.89 mg/dl and 8.04±6.09 g/day, respectively; and stage I, II, III, IV and V renal disease were present in 19.2%, 13.7%, 16.4%, 11%, and 39.7% of the patients, respectively. ESRD developed in 16 patients during the follow-up period. All of the ESRD patients started a dialysis programme. Thirty patients (41%) died during the follow-up period; median patient survival was 35.9±6.12 months. Old age, tuberculosis etiology, advanced renal disease and low serum albumin levels were associated with a worse prognosis. Serum albumin was a predictor of mortality in logistic regression analysis.

CONCLUSION

The ultimate outcome of the patients with AA amyloidosis is poor, possibly due to the late referral to the nephrology clinics. Early referral may be helpful to improve prognosis.

Treatment strategies for amyloid A amyloidosis

BACKGROUND

Amyloid A (AA) amyloidosis is a serious complication of a wide range of chronic inflammatory, infectious and neoplastic diseases. A longstanding overproduction of the liver-synthesised cytokine-induced acute phase serum amyloid A (SAA) protein is a key event in the pathogenetic cascade leading to the deposition of AA amyloid in tissues and organs.

OBJECTIVE

The aim of the study was to critically review treatment strategies in AA amyloidosis.

METHODS

A systematic literature review was conducted based on PubMed (January 1980 - April 2008) and selected conference abstracts.

RESULTS/CONCLUSIONS

The current strategy for the treatment of AA amyloidosis is firmly based on the knowledge of the underlying pathogenetic mechanism and aims at reducing the amyloid precursor (SAA) load by intensive anti-inflammatory/immunosuppressive therapy and, in selected instances, anticytokine (TNF-alpha, IL-1beta or IL-6 blockade) therapy, or, when applicable, the eradication of an existing infectious focus (surgery, antimicrobial drugs). Emerging strategies focus on the dissolution of the amyloid deposits using small molecules that either interact with the glycosaminoglycans or the fibril component of the deposits, or deplete amyloid P component.

Significance of SAA1.3 allele genotype in Japanese patients with amyloidosis secondary to rheumatoid arthritis

OBJECTIVE

To clarify the clinical significance of the SAA1.3 allele in the development and outcome of AA amyloidosis in Japanese patients with rheumatoid arthritis (RA).

METHODS

One hundred and twenty RA patients (60 alive and 60 dead) fulfilling the 1987 ACR criteria and 62 RA patients with biopsy-confirmed amyloid A (AA) amyloidosis (36 alive and 26 dead) were enrolled. The SAA1 genotypes were determined by PCR-based restriction fragment length polymorphism. To predict the clinical outcome of AA amyloidosis, we investigated characteristics and survival, focusing on the SAA1.3 allele retrospectively.

RESULTS

The SAA1.3 allele genotype was not only a risk factor for the association of AA amyloidosis but also a poor prognostic factor for the development of AA amyloidosis (P=0.015). Both the association of AA amyloidosis arising early in the RA disease course and symptomatic variety and severity were found in amyloidotic patients with the SAA1.3 allele. The presenting factors adversely influenced were age (P=0.001), lowered serum albumin (P=0.001) and creatinine concentration (P=2.14 x 10(-5)). Renal involvement was associated with poor survival in patients with AA amyloidosis (P=0.011) and the presence of cardiac involvement was likely to be a risk factor for survival (P=0.062). The rate of the causes of death in respect to the category of infection, gastrointestinal diseases, and renal failure was higher in patients with AA amyloidosis than in those without amyloidosis, gastrointestinal diseases and renal failure. Cyclophosphamide was found to be superior to methotrexate in the management of RA patients with AA amyloidosis.

CONCLUSION

Our data support the fact that homozygosity for the SAA1.3 allele is a univariate predictor of survival in addition to a risk factor for the association of AA amyloidosis adversely influencing the outcome in Japanese RA patients. Renal involvement is a pivotal clinical manifestation in the development of AA amyloidosis, as is likely to be cardiac involvement in AA amyloidosis secondary to RA.

[Extra-articular manifestations and complications of ankylosing spondylitis]

Extra-articular manifestations can be defined as all symptoms and signs etiopathogenically related, at least in part, to ankylosing spondylitis (AS) that arise in the various organs and tissues of the locomotor apparatus. Thus, ocular, intestinal and cardiac manifestations, which are common to all spondylarthritides through their association with HLA-B27, are grouped under this heading. Complications include clinical manifestations that result from persistent spondylitic activity and/or treatment. Table 1 provides a list and the main characteristics of these manifestations. Obviously, this classification is far from perfect since, among other factors, knowledge of the etiopathogenesis of AS is still fairly limited.

Renal type AA amyloidosis associated with rheumatoid arthritis: a cohort study showing improved survival on treatment with pulse cyclophosphamide

OBJECTIVE

To determine the incidence of renal AA amyloidosis and its association with rheumatoid arthritis (RA) in a cohort of all renal biopsies at one referral hospital and to measure the effect of a monthly pulse of cyclophosphamide on renal function and survival in these RA patients.

METHOD

All renal biopsies with proven AA amyloidosis from a single pathology unit linked to a major nephrology referral unit in a university hospital were selected retrospectively and RA patients were identified. We studied 6931 renal biopsies. The effect of treatment with and without pulse cyclophosphamide on renal function and survival was studied in these patients.

RESULTS

From March 1977 to February 1999, the incidence of AA amyloidosis was 2.4 cases/yr. The incidence and prevalence of the association of AA amyloidosis with RA were 0.68 cases/yr and 0.22% (15/6931) respectively. RA patients treated with cyclophosphamide (n=6) had a lower rate of renal function loss (P=0.013) and a higher median survival (P=0.026) than untreated patients (n=9). During the follow-up period, two out of six treated patients (33%) and all nine untreated patients (100%) died.

CONCLUSIONS

AA amyloidosis is a rare complication of RA and complicates the evaluation of treatment. This retrospective study suggests that treatment with cyclophosphamide is able to reduce the incidence of end-stage renal failure and to increase survival. Prospective studies are needed to clarify this issue.

Amyloid precursors and amyloidosis in inflammatory arthritis

Recent data demonstrating the multifunctional role of serum amyloid A (SAA) in the pathogenesis of amyloidosis have yielded important insights into this potentially fatal consequence of chronic inflammation. SAA has been shown to participate in chemotaxis, cellular adhesion, cytokine production, and metalloproteinase secretion and is thus integrally involved in the disease process. In addition to its production by the liver as part of the acute phase response, SAA is also expressed by several pathologic tissues such atherosclerotic plaques, rheumatoid synovitis and in the brains of patients with Alzheimer disease. Its constitutive production in normal tissue suggests a role for SAA in host defense and tissue turnover. Many pathways are involved in the regulation of SAA, and as more becomes known about these, potential therapeutic targets may be identified. However, the prevention of secondary amyloidosis is best achieved by early and adequate treatment of patients with chronic inflammatory disorders. Suppression of the acute phase response and normalization of SAA levels are likely to significantly impact on the incidence of amyloidosis in inflammatory arthritis.

Amyloid precursors and amyloidosis in rheumatoid arthritis

Amyloidosis refers to the extracellular accumulation of amyloid fibrils, derived from a circulating precursor, in various tissue and organs. The most common form of amyloidosis worldwide is that which occurs secondary to chronic inflammatory disease, particularly rheumatoid arthritis. The precursor molecule is serum amyloid A (SAA), an acute phase reactant, which can be used as a surrogate marker of inflammation in many diseases. SAA has a number of immunomodulatory roles, can induce chemotaxis and adhesion molecule expression, has cytokine-like properties and can promote the upregulation of metalloproteinases. It enhances the binding of high density lipoprotein to macrophages and thus helps in the delivery of lipids to sites of injury for use in tissue repair. It is thus thought to be an integral part of the disease process. Moreover, elevated levels of SAA over time predispose to secondary amyloidosis. Pathogenic factors underlying this disease are outlined along with guidelines for diagnosis and management.

Regression of the nephrotic syndrome in rheumatoid arthritis and amyloidosis treated with azathioprine. A case report

Secondary or reactive (AA) amyloidosis is a well-known complication of certain rheumatic diseases, particularly rheumatoid arthritis (RA). This case report describes a patient with RA complicated by amyloidosis and the nephrotic syndrome, which regressed after treatment with azathioprine. The AA amyloidosis was documented by renal and lymph node biopsies and by the presence of proteinuria. Evaluation for other etiologies of proteinuria was negative. After treatment with azathioprine, the proteinuria resolved and the serum albumin level increased from 1.9 mg/dl to normal. This is the first published report of azathioprine therapy resulting in a reversal of the nephrotic syndrome in a patient with RA and secondary amyloidosis.

Treatment of amyloidosis

Amyloidosis is the extracellular deposition of normally soluble autologous protein in a characteristic abnormal fibrillar form. Systemic amyloidosis and some local forms are progressive, cause major morbidity, and are often fatal. No treatment specifically causes the resolution of amyloid deposits, but therapy that reduces the supply of amyloid fibril precursor proteins can improve survival and preserve organ function. Major regression of amyloid occurs in at least a proportion of such cases, suggesting that the clinical improvement reflects mobilization of amyloid. The clearest evidence for regression of amyloid has been obtained in juvenile rheumatoid arthritis patients with AA amyloidosis treated with chlorambucil. This drug suppresses the acute phase production of serum amyloid A protein, the precursor of AA amyloid fibrils, and is associated with remission of proteinuria and greatly improved survival. In many such patients, scintigraphy with serum amyloid P component shows major regression of amyloid over 12 to 36 months and frequently reveals a discrepancy between the local amyloid load and organ dysfunction. Measurement of target organ function is therefore not an adequate method for monitoring treatment aimed at promoting the resolution of amyloid. In monoclonal immunoglobulin light chain (AL) amyloidosis the aim of treatment is to suppress the underlying B-cell clone and, therefore, production of the amyloid fibril precursor protein. This can be difficult to achieve or sustain and, since the prognosis is so poor, many patients die before benefits of therapy are realized. A recent development has been the introduction of liver transplantation as treatment for familial amyloid polyneuropathy caused by transthyretin gene mutations. This leads to the disappearance of variant transthyretin from the plasma and halts progression of the neurologic disease. Features of autonomic neuropathy frequently ameliorate, and improvement in peripheral motor nerve function has been recently reported. Serum amyloid P component scans show regression of associated visceral amyloidosis. This surgical form of gene therapy holds much promise for patients with familial amyloid polyneuropathy and has been widely adopted. The only other form of amyloidosis in which the supply of the fibril precursor protein can be sharply reduced is beta 2M amyloidosis in long-term hemodialysis patients. Renal transplantation lowers the plasma concentration of beta 2M to normal levels and is associated with rapid improvement of the osteoarticular symptoms. Preliminary observations suggest that the beta 2M amyloid deposits also can regress in some patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Amyloidosis

Amyloidosis is a heterogeneous group of disorders characterized by extracellular deposition of abnormal protein fibrils which are derived from different proteins in different forms of the disease. Asymptomatic amyloid deposition in a variety of tissues is a universal accompaniment of ageing, and clinical amyloidosis is not rare. Intracerebral and cerebrovascular beta-protein amyloid deposits are a hallmark of the pathology of both sporadic and familial Alzheimer's disease, beta 2-microglobulin-derived amyloid is a common complication of long term haemodialysis, and islet amyloid polypeptide is the fibril protein in the universal islet amyloidosis of type II diabetes mellitus. New fibril proteins have lately been identified in hereditary amyloidosis, including variants of gelsolin, apolipoprotein AI, lysozyme and fibrinogen. The development of radiolabelled serum amyloid P component (SAP) scintigraphy has allowed amyloid to be diagnosed non-invasively in vivo for the first time, provided unique insight into the distribution and size of amyloid deposits, and yielded novel information on the natural history and the effects of treatment. Amyloid deposits are in a state of dynamic turnover and can regress if new fibril formation is halted. The recent elucidation of the three dimensional structure of human SAP may enable the design of specific therapeutic agents.

Clinical and therapeutic aspects of AA amyloidosis

Approach to the management of AA amyloidosis complicating RA. (A) In case of proteinuria or loss of renal function a rectal biopsy or a subcutaneous fat biopsy is a suitable screening method for the detection of amyloidosis. If in any doubt, try to ascertain the diagnosis by renal biopsy. Adequate staining with alkaline Congo red and preferably immunohistochemical staining with anti-AA antibodies should be performed. Beware of renal pathology other than amyloidosis even in the presence of a positive rectal biopsy. (B) A vigorous attempt to control disease activity of the RA should be made in order to eliminate the production of SAA, an acute phase protein. The response to treatment should be monitored by serial measurements of CRP and preferably SAA. (C) The function of some vital organs should be evaluated: (a) endogenous creatinine clearance and the extent of proteinuria; (b) electrocardiogram and optional echocardiography; (c) thyroid function and adrenocortical function; (d) intestinal absorption tests; (e) optional--SAP scintigraphy and turnover studies. (D) Attention should be given to adequate supportive treatment: (a) blood pressure control; (b) treatment of intercurrent infections; (c) corticosteroids during major surgical procedures; (d) pay attention to the possible effect of NSAID on proteinuria and renal function. (E) In case of total renal failure or uncontrollable proteinuria: (a) consider the possibility of primary renal transplantation; (b) otherwise regular haemodialysis is indicated.

Colchicine in the treatment of AA and AL amyloidosis

Colchicine is an effective medication in the prevention and treatment of amyloidosis of familial Mediterranean fever. Its therapeutic effect depends on the stage of renal disease and the drug dose. To evaluate colchicine effect in AA amyloidosis of other diseases and in primary AL amyloidosis, the literature was reviewed. Findings were that (1) the effect of colchicine in reactive amyloidosis has not been methodically studied, but anecdotal reports suggest it may be beneficial; and (2) the results of studies and case reports on the effect of colchicine in primary amyloidosis are conflicting. Because a therapeutic effect of colchicine in primary and reactive amyloidosis has been shown in sporadic cases, a prospective, controlled, multicenter study assessing the effect of colchicine in all types of amyloidosis appears to be justified. Until such a study is available, the addition of colchicine in an appropriate dose to any therapeutic regimen of patients with AA or AL amyloidosis should be considered.

De novo amyloidosis in a renal allograft: a case report and review of the literature

Recurrent amyloidosis is an uncommon but well-documented event in up to 26% of renal allograft recipients transplanted for amyloid renal disease. Both primary and secondary amyloidoses recur. De novo primary and secondary amyloid have not been previously reported. We report the first occurrence of de novo secondary amyloid in a renal allograft recipient. The cause of the secondary amyloidosis is unproven, but possible etiologies include inflammation secondary to occult hepatitis, rheumatoid arthritis, or chronic rejection. Colchicine therapy has not resulted in decreased proteinuria or improved renal function.

Serum amyloid P component scintigraphy and turnover studies for diagnosis and quantitative monitoring of AA amyloidosis in juvenile rheumatoid arthritis

OBJECTIVE

To evaluate aspects of the natural history of AA amyloidosis complicating juvenile rheumatoid arthritis (JRA), and its response to therapy with chlorambucil.

METHODS

Scintigraphy and 7-day turnover studies were performed in JRA patients with histologically proven (n = 35) or clinically suspected (n = 30) AA amyloidosis, following intravenous injection of 123I and 125I-labeled serum amyloid P component (SAP). Prospective monitoring studies were performed over 2-3 years in 20 patients with amyloidosis. All but 2 amyloidosis patients were treated with chlorambucil.

RESULTS

Positive scanning results were obtained in all patients in whom imaging was performed within 12 years of positive biopsy findings of amyloid and in 5 patients with clinically suspected amyloidosis. Negative scanning results with normal SAP metabolism, indicating regression of amyloid, were obtained in 4 patients whose amyloidosis had been in full clinical remission for more than 12 years. Prospective monitoring studies in patients whose JRA-associated inflammatory activity was in remission demonstrated regression of amyloid in 8 patients and no substantial changes in 8 others; however, in 4 further patients with active inflammation, there was accumulation of amyloid. There was a very poor correlation between the amount of amyloid present at a particular site and the resultant organ dysfunction.

CONCLUSION

Radiolabeled SAP scintigraphy and turnover studies are useful complementary tools in the diagnosis, screening, and quantitative monitoring of type AA amyloidosis in JRA. The amyloid deposits may progress and/or regress at different rates in different anatomic sites over short periods.

Therapy of amyloid diseases

Deposition of amyloid in the organism can lead to severe clinical symptoms and syndromes which are referred to as amyloidosis. However, amyloidosis is not a pathogenetically single disease entity. Various amyloid diseases are known which can clearly be distinguished by identifying the protein from which the amyloid is derived. Since the amyloid syndromes are pathogenetically diverse, each of the different amyloid diseases needs to be treated differently, and a type-specific amyloid therapy is mandatory. Unfortunately, an efficient therapy is not yet available for most amyloid syndromes. It is the purpose of this review to show how the different amyloid syndromes are distinguished definitively from each other and what has been successful in the effort to establish an efficient therapy of the various amyloid deposits and different amyloidoses.

Amyloidosis

Amyloidosis is a heterogenous group of diseases characterized by deposition of a fibrillar, proteinaceous material, amyloid, in various tissues and organs. Increasing knowledge about the different proteins that constitute the amyloid fibrils has made it possible to classify amyloidosis by the fibril protein, which appears more rational than the traditional classification by its clinical expression. A serum protein is the precursor of the amyloid fibril protein in the various systemic forms of amyloidosis. Although the chemical composition of amyloid is presently well known, the pathogenetic processes that convert such proteins into a fibrillar form and lay them down in the tissues are far from clarified. This review describes the amyloid deposits, some putative pathogenetic mechanisms, and the clinical, therapeutic, and prognostic aspects of the most important forms of amyloid disease.

Long-term outcome of rheumatoid arthritis

Although developments in surgical and medical treatment methods have improved the average long-term outcome of rheumatoid arthritis (RA), it still is a severe disease. An 8-year follow-up study of patients with seropositive RA showed a large variation in the outcome. Only 24 percent of patients had no progression in the radiological destruction of the joints of hands and feet. Premature mortality seems to accumulate in patients with a poor outcome. Study of prognostic markers for RA would be of great importance.

Azathioprine, cyclophosphamide and chlorambucil

Immunosuppressive agents serve a major role in the management of once-fatal conditions such as the systemic necrotizing vasculitides, but they are also being used in more common, chronic inflammatory disorders such as rheumatoid arthritis. The drugs are all capable of reducing cell division but they differ in their modes of action. This is in keeping with their differing rates of action, and different indications. Azathioprine is a valuable alternative to slow-acting antirheumatic drugs in older patients with rheumatoid arthritis. Cyclophosphamide has transformed the outlook of many forms of vasculitis. Chlorambucil is particularly useful in improving the prognosis for children with amyloidosis secondary to juvenile chronic arthritis. We have tried to highlight the role of these drugs in a number of rheumatic diseases. We have emphasized their clinical applications, with some laboratory evidence for their effects. The major side-effects are reviewed. Finally, we have discussed their possible mechanisms of action.

Evaluation of systemic amyloidosis by scintigraphy with 123I-labeled serum amyloid P component

BACKGROUND

In systemic amyloidosis the distribution and progression of disease have been difficult to monitor, because they can be demonstrated only by biopsy. Serum amyloid P component (SAP) is a normal circulating plasma protein that is deposited on amyloid fibrils because of its specific binding affinity for them. We investigated whether labeled SAP could be used to locate amyloid deposits.

METHODS

Purified human SAP labeled with iodine-123 was given intravenously to 50 patients with biopsy-proved systemic amyloidosis--25 with the AL (primary) type and 25 with the AA (secondary) type--and to 26 control patients with disease and 10 healthy subjects. Whole-body images and regional views were obtained after 24 hours and read in a blinded fashion.

RESULTS

In the patients with amyloidosis the 123I-SAP was localized rapidly and specifically in amyloid deposits. The scintigraphic images obtained were characteristic and appeared to identify the extent of amyloid deposition in all 50 patients. There was no uptake of the 123I-SAP by the control patients and the healthy subjects. In all patients with AA amyloidosis the spleen was affected, whereas the scans showed uptake in the heart, skin, carpal region, and bone marrow only in patients with the AL type. Positive images were seen in six patients in whom biopsies had been negative or unsuccessful; in all six, amyloid was subsequently found on biopsy or at autopsy. Progressive amyloid deposition was observed in 9 of 11 patients studied serially.

CONCLUSIONS

Scintigraphy after the injection of 123I-SAP can be used for diagnosing, locating, and monitoring the extent of systemic amyloidosis.

Amyloidosis

The clinical amyloidosis syndromes are a heterogeneous group of disorders characterised by abnormal extracellular accumulation of autologous protein material. Amyloid deposits are largely composed of insoluble protein fibrils which are intimately associated with sulphated glycosaminoglycan residues. Amyloid P component (AP) is a minor but almost universal constituent of the deposits and is derived from the normal circulating glycoprotein serum amyloid P component (SAP), a member of the pentraxin family of plasma proteins. The current classification of amyloidosis is based on the chemical nature of the fibril protein subunits. Systemic amyloidosis is well known as a relatively rare but important cause of serious morbidity, and vital organ involvement is usually fatal. In recent years it has become increasingly recognised that amyloid deposition in a variety of sites is a universal feature of ageing, and in particular that amyloid in the cerebral blood vessels and within the brain itself is an integral part of the pathology of Alzheimer's disease. Also recently, a new form of amyloid has emerged, confined to patients who have received long term haemodialysis for end stage renal failure, in whom beta 2-microglobulin (beta 2M) is laid down as amyloid fibrils predominantly in periarticular and bony tissues. Considerable progress in knowledge of the composition, molecular structure and properties of many different constituents of amyloid has been made in the past 30 years. However, the precise mechanisms of amyloid fibril formation, deposition and persistence are not known and no generally effective therapy yet exists which can arrest amyloid deposition or promote its resolution. A major reason for our ignorance of the natural history of amyloidosis is that it is an exclusively histological diagnosis, at the time of which most patients with systemic disease have extensive amyloid deposits throughout many organs and a very poor prognosis. Some optimism has been generated from recent work suggesting that amyloid fibrils are not inherently non-biodegradable and that the use of radiolabelled SAP may permit non-invasive sensitive, scintigraphic imaging of amyloid deposits in vivo.

Diagnostic radionuclide imaging of amyloid: biological targeting by circulating human serum amyloid P component

The specific molecular affinity of the normal plasma protein, serum amyloid P component (SAP), for all known types of amyloid fibrils was used to develop a new general diagnostic method for in-vivo radionuclide imaging of amyloid deposits. After intravenous injection of 123I-labelled purified human SAP there was specific uptake into amyloid deposits in all affected patients, 7 with systemic AL amyloid, 5 with AA amyloid, and 2 with beta 2M amyloid, in contrast to the complete absence of any tissue localisation in 5 control subjects. Distinctive high-resolution scintigraphic images, even of minor deposits in the carpal regions, bone marrow, or adrenals, were obtained. This procedure should yield much information on the natural history and the management of amyloidosis, the presence of which has hitherto been confirmed only by biopsy. Clearance and metabolic studies indicated that, in the presence of extensive amyloidosis, the rate of synthesis of SAP was greatly increased despite maintenance of normal plasma levels. Furthermore, once localised to amyloid deposits the 123I-SAP persisted for long periods and was apparently protected from its normal rapid degradation. These findings shed new light on the pathophysiology of amyloid and may have implications for therapeutic strategies based upon specific molecular targeting with SAP.