|
 
 |
| ORIGINAL ARTICLE |
|
| Year : 2015 | Volume
: 3
| Issue : 2 | Page : 209-214 |
|
Profile of systemic sclerosis and associated renal involvement
Neehar Shanavas, Anup K Das
Department of Medicine, Assam Medical College, Dibrugarh, Assam, India
| Date of Web Publication | 16-Dec-2015 |
Correspondence Address:
Anup K Das
Department of Medicine, Assam Medical College, Dibrugarh - 786 002, Assam
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/2321-4848.171908
Background: Systemic sclerosis (SSc) patients are encountered in all parts of the world. Few Indian studies are found in the literature on this connective tissue disorder of unknown etiology. The spectrum of sclerodermatous diseases comprises a wide variety of clinical entities. Renal involvement is not common in Indian patients when compared to western patient's in spite of the kidney being commonly affected in scleroderma due to vascular changes. Aim and Objective: To primarily study the prevalence of renal involvement in SSc and to correlate it with high-sensitivity C-reactive protein (hsCRP) over a period of 1 year in a tertiary care hospital in North-East India. Materials and Methods: A total of 38 consecutive scleroderma patients of both sexes, diagnosed by established criteria, were examined, and hsCRP was estimated in all. Evaluation for nephropathy by biochemical tests and sonography were carried out. Relevant clinical/biochemical examinations were carried out. Results: SSc was 3 times more common in mostly in middle aged females. About 50% presented within 1 year of disease onset. Renal involvement was uncommon (18%) and hsCRP was detected in 26%. Conclusion: SSc with nephropathy, not renal crisis, presents early and hsCRP is a good marker for the same. Keywords: High-sensitivity C-reactive protein, renal involvement, scleroderma, scleroderma renal crisis, systemic sclerosis
How to cite this article:
Shanavas N, Das AK. Profile of systemic sclerosis and associated renal involvement. Arch Med Health Sci 2015;3:209-14 |
| Introduction | |  |
Systemic sclerosis (SSc) is a connective tissue disorder of unknown etiology, and heterogeneous clinical manifestations. It has a chronic and often progressive course, characterized by alterations of the microvasculature, disturbances of the immune system, and by massive deposition of collagen in the connective tissue. It is generally considered an aggressive form of scleroderma, characterized by induration and thickening of the skin. It may occur in a localized form or as a systemic disease (SSc), which is often progressive and fatal. Currently recognized subsets of scleroderma include: Diffuse (progressive SSc), limited, localized (morphea and linear scleroderma), overlap syndromes, and undefined connective tissue disease.
Systemic sclerosis is a sporadic disease that has a worldwide distribution involving every ethnic group. No seasonal or geographic clustering of cases has been confirmed. The epidemiology of SSc has been difficult to establish, reflecting the clinical diversity of the disease, the absence of widely accepted criteria for diagnosis or classification, and the methodologic challenges associated with population-based case studies. Incidence estimates range from 9 to 19 cases/1 million/year, with prevalence rates ranging from 28 to 253 cases/1 million/year in the United States, [1],[2] and 120 cases/1 million/year in the United Kingdom. [3],[4] Based on incidence and survival rates, it is estimated that there are 75,000-100,000 cases of SSc in the USA where a community-based survey of SSc yielded a prevalence of 286 cases/million people [5] suggesting that SSc is frequently misdiagnosed, and its true prevalence may be higher than previously reported.
The kidney shows the most significant acute consequences of vasospasm and arterial damage in SSc. In contrast to pulmonary arterial hypertension (which is characterized by slowly progressive vasculopathy), the vascular changes in renal scleroderma usually develop rapidly, due to higher levels of systemic blood pressure as compared to the pulmonary pressure. In both, an abnormal response to vascular injury is the underlying pathology. In scleroderma renal crisis (SRC), intrinsic systemic vasospasm leads to accelerated hypertension and occurs in approximately 10% of all scleroderma patients. Patients with diffuse scleroderma are at greatest risk, with 20-25% of them developing SRC. [6] They had a high mortality and 1-year survival <15% [7] prior to the advent of effective therapy. However, nonrenal-crisis abnormalities like hypertension, azotemia or proteinuria still occur in 45-60%. [8] Overall, renal involvement is reportedly uncommon in Indian patients with SSc [9] while nonrenal abnormalities are similar to the west. [10]
C-reactive protein (CRP) is an abnormal protein (acute phase reactant) which forms a precipitate with the somatic C polysaccharide of the pneumococci. CRP-ligand complexes bind directly to neutrophils, macrophages, and other phagocytic cells, leading to inflammatory response and release of cytokines. Elevated CRP is found in many infectious and noninfectious inflammatory conditions and used as a marker for disease activity.
| Materials and Methods | | |
The present prospective, hospital based study was undertaken in the Department of Medicine, Assam Medical College Hospital, Dibrugarh, Assam, to study the prevalence of renal involvement in SSc and to correlate it with high-sensitivity C-reactive protein (hsCRP). The study duration was from July 2012 to June 2013. A total of 38 consecutive patients of SSc of both sexes, ≥13 years of age admitted or attending various outpatient departments were included in the study who fulfilled the American College of Rheumatology Criteria for SSc.
Exclusion criteria
Patients with other connective tissue disease, diabetes mellitus, primary renal disorders, pregnancy, and patient not giving consent.
The followings were carried out:
- Details of the disease/duration/treatment, family history, history of other rheumatological diseases
- Examination specially for Raynaud's phenomenon, skin thickening, subcutaneous calcinosis, telangiectasia, arthralgia/arthritis, myopathy, esophageal dysmotility, renal crisis by appropriate investigations
- Respiratory, urinary or other systemic infections were excluded by clinical examination, chest X-rays, blood/urine analysis, and other relevant examinations. If present, the hsCRP was estimated only after controlling/treating the infections.
Diagnostic criteria for scleroderma
According to the subcommittee for scleroderma criteria of American Rheumatism Association (1980): [11]
- Major criteria:
- Scleroderma proximal to the digits, affecting the limbs, face, neck or trunk.
- Minor criteria:
- Sclerodactyly.
- Digital pitting scar.
- Bilateral basal pulmonary fibrosis.
Diagnosis of scleroderma was confirmed when one major criteria or two minor criteria's were fulfilled (sensitivity and specificity 97% and 98% respectively). All patients were carefully evaluated to look for the renal involvement, with history suggestive of SRC in the past, measurement of blood pressure, urine examination for the presence of proteinuria and active sediment, blood biochemistry for measurement of serum urea and creatinine, electrolytes, uric acid, antinuclear antibodies (ANA), and creatinine clearance using Cockcroft-Gault formula:
The factor of 0.85 was used for females.
Based on the calculated glomerular filtration rate (GFR), chronic kidney disease was classified as stage 2 with GFR between 60 and 89 ml/min, stage 3 with GFR between 30 and 59 ml/min, stage 4 with GFR between 15 and 29 ml/min and kidney failure when GFR was <15 ml/min and/or requiring regular dialysis.
Serum hsCRP was estimated by Dimension RxL Max autoanalyzer using Particle Enhanced Turbidimetric Immunoassay technique (normal value: 0-3 mg/L). Ultrasonography kidney was done using Siemens Acuson Antares 5 Ultrasound System with 3.5 MHz transducer.
Statistical analyses for all continuous variables were expressed as mean ± SD, whereas categorical variables were expressed as frequencies and their percentages. Student's t-test was performed for continuous variables, and Fishers exact test for categorical variables. P ≤ 0.05 was considered as significant.
| Results and Observations | | |
The mean age of the study population was 41.76 ± 11.53 years (M:F = 1:3.22). The maximum age incidence 14 (36.84%) was seen in 31-40 years. The age and sex distribution is depicted in [Table 1]. Duration of disease before presentation ranged from 1 month to 9 years. The mean duration of the presentation was 23.38 months with 19 patients (50%) presenting within 1 year of onset. Renal involvement was more common during the first 2 years of the disease. Out of the total seven cases with renal involvement, six patients (86%) developed the same within first 2 years. Major presenting symptoms were sclerodactly (74%), Raynaud's phenomenon (63%), digital ulcer (37%), joint pain (76%), dysphagia (32%), calcinosis (5%), dyspnea (24%), and hypopigmentation (21%) [Figure 1]. ANA was positive in 21 cases (55%).
7/38 patients (18%) had renal involvement consisting of one male and six female patients (P = 1.0000). Out of them, 4 cases (57%) were already on corticosteroid therapy (P = 0.0245). Renal findings included proteinuria in 7 cases (18%), elevated blood urea in 4 (11%), high-serum creatinine in 4 (11%), renal parenchymal changes in ultrasonogram in 2 (5%) while one patient (3%) presented with SRC [Table 2].
About 28 (74%) had normal hsCRP levels while 10 cases (26%) had elevated hsCRP levels. Renal involvement was found in 5 cases with high hsCRP and 2 cases with low-hsCRP levels. Rest of 5 cases with hsCRP and 26 low-hsCRP levels had no renal involvement [Figure 2]. Association between hsCRP and renal involvement in SSc was highly significant (P = 0.008). Out of the total seven patients with proteinuria, 5 (71%) had elevated hsCRP levels. All the patients with renal parenchymal changes in ultrasound abdomen, elevated urea, elevated creatinine and SRC had elevated hsCRP levels. | Figure 2: High-sensitivity C-reactive protein correlation with and without renal manifestations
Click here to view |
| Discussion | | |
Incidence of SSc increases with age, peaking in the 3 rd to 5 th decade. In a study of 100 Indian patients, Sharma et al.[12] found that mean age was 32.75 ± 11.62 years. So, the mean age of our subjects is comparable to other Indian data. It was observed that women were more commonly affected than men. Earlier reports of Laing et al.[13] and Sharma et al. [12] showing a female to male ratio 3:1 and 5.2:1 respectively, conforming to our findings.
Clinically, skin thickening is present in almost all cases, [14] digital pitting scar in >33.33% cases, [15] skin pigmentation in ~50% [16] and arthralgia/arthritis in 70% of diffuse variety and 40% of limited variety of the disease. Arthritic pain is not uncommon as also radiographic evidence of periarticular osteoporosis, joint space narrowing and erosion. [17],[18] Esophageal involvement and dysphagia can occur in 33% and 35.2% patients respectively. [12] These are comparable to our findings [Figure 1]. In USA, Reveille et al.[19] found that ANA was positive in 65.3% of the SSc, which is comparable to the present study.
Human CRP is a homogeneous protein free of lipid and carbohydrate. The binding and functional character of CRP suggests that it may play a role in host defense against various infections/inflammations. CRP is synthesized by hepatocytes and as it is normally present in plasma at a concentration <5 mg/L, highly sensitive immunochemical methods are required for its quantification. The rate of synthesis of CRP is possibly influenced by humoral mediators like leukocyte endogenous mediator (LEM) as studies have shown that injection of LEM in rats causes elevation of a number acute phase proteins. [20] The protective efficacy of CRP against Streptococcus pneumonia infection in mice was demonstrated in 1981 by Carolyn Mold and Shuei Nakayam. CRP has binding specificity for phosphocholine determinants of cell wall polysaccharide from S. pneumoniae.
Recent studies from China and Canada [21],[22] have found hsCRP elevation in 25-35.4% of SSc patients while two small cohorts from Japan, [23],[24] reported that 33-50% had elevated CRP levels. In a mostly prevalent SSc database, CRP level seems to regress over time. Higher values are associated with activity and damage scales. CRP level may be elevated early disease when cytokines are causing more inflammation, and decline later as fibrosis progresses.
The kidney commonly shows the consequences of blood vessel spasm and arterial damage in SSc and studies suggest a strong association between renal involvement and outcomes in scleroderma. In SRC, intrinsic systemic vasospasm leads to accelerated hypertension. Autopsy studies reveal histological evidence of renal involvement in 60-80% of patients with SSc. [25],[26] As many as 50% of SSc patients have clinical evidence of renal involvement, such as mild proteinuria, elevated serum creatinine concentration, or hypertension. [27],[28] The course of renal involvement in most of them appears to be benign, without progression of renal dysfunction. [28] Mild chronic renal insufficiency in scleroderma may be a manifestation of vasculopathy and is probably under recognized. Current data suggests that manifestations of renal insufficiency including proteinuria and altered renal vascular dynamics as measured with Doppler ultrasound may help identify early signs of renal involvement which can be a surrogate marker of vasculopathy. Further studies are warranted to investigate renal markers as prognostic indicators and targets for disease modifying therapy in scleroderma.
It is likely that in some patients, proteinuria and hypertension are coincidental and not an effect of SSc. Although SRC develops in up to 20% with diffuse cutaneous SSc (dcSSc), its incidence appears to be declining. [28] Other patterns of renal involvement in SSc include chronic vasculopathy with reduced GFR. Patients with overlap SSc may develop inflammatory glomerular disease including glomerulonephritis, characteristically associated with serologic features.
Our study shows that the renal involvement is less frequent in our patients compared to the reports in western literature. Renal involvement was reported in 23-40% in Western countries, in contrast to our figure, which are similar to that of Iraq and Thailand, [29],[30] and previous Indian studies, emphasizing a racial variation in frequency of renal involvement in SSc [Table 3]. In a large western study [22] of 1145 SSc patients it was found that patients with elevated CRP levels was associated with higher disease activity, higher creatinine, and higher prevalence of proteinuria; and were more likely to use steroids. In our study, association of corticosteroid therapy with renal involvement in SSc was significant (P = 0.0245). We also found that renal involvement was more common (86%) during the first 2 years of the disease. Most cases of renal involvement reportedly occur within the first 12 months of disease, and in a quarter of patients with SRC, the diagnosis of SSc is made at the time of the renal presentation. [28]
Scleroderma renal crisis typically causes accelerated hypertension and acute renal failure. The only patient who presented with SRC in our study had disease duration of 24 months. She was on high-dose steroid following an allergic skin reaction to penicillamine therapy. One month later she came with rapidly progressive oliguria renal failure and severe hypertension. A single-center study in the UK consisting of 706 patients [32] found that 12% of dcSSc patients and 2% of limited cutaneous SSc (lcSSc) patients later on developed SRC. Until the advent of angiotensin-converting enzyme inhibitors, SRC had a very high mortality. But in recent years, 1 year mortality has declined from 85% to 24%. [33] The diagnosis of SRC is based upon the characteristic findings in high-risk patients with SSc. SRC is a thrombotic microangiopathy similar to malignant nephrosclerosis, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, radiation nephritis, chronic transplantation rejection, and antiphospholipid antibody syndrome. Because of the similar histologic findings, renal biopsy cannot definitively establish the diagnosis of SRC.
Scleroderma renal crisis occurs in 10-15% of patients with dcSSc and rarely (1-2%) in lcSSc. [32] Most cases occur within the 1 st year of disease, and in 25% of patients with SRC, the diagnosis of SSc is made at the time of the renal presentation. A number of risk factors for SRC have been identified. These include diffuse and advancing skin involvement, glucocorticoid use, and presence or absence of certain autoantibodies; the most important one being diffuse skin involvement, particularly if rapidly progressive. [34],[35] End-organ damage can lead to encephalopathy with generalized seizures or flash pulmonary edema. Microangiopathic hemolytic anemia is common, and disseminated intravascular coagulation and thrombocytopenia may develop. Approximately two-third of SRC require renal replacement therapy. [32] Of these, half usually recover sufficiently to discontinue dialysis by 24 months, and hence decisions about renal transplantation should be postponed until that time. Many patients requiring renal replacement therapy eventually come off dialysis 6-24 months after the renal crisis. Therefore, final decision on renal transplant should be postponed until at least 2 years after the renal crisis. Renal biopsy may provide prognostic information and confirms the diagnosis. Cases of SSc with inflammatory glomerular pathology have been identified, and will need different treatment compared with classic SRC. A delayed renal recovery distinguishes SRC from other causes of end-stage renal failure.
Scleroderma renal crisis has been linked to corticosteroid therapy; with 60% of the patients having received corticosteroids prior to presentation [32],[36] especially with high-dose corticosteroid (e.g., prednisolone or equivalent at >15 mg/day).
| Conclusion | | |
Our study, despite in a small number of patients, shows that SSc is not rare in this part of the country. Mostly middle aged females are the usually affected. Renal involvement is present in about one-fifth of these patients, and association of hsCRP with renal involvement in SSc is significant, and it may be a helpful marker. We observed that SRC is very rare in Indian patients with SSc. However, nonrenal manifestations and another renal involvement appears to be as common in Indian patients with SSc as in the western population. There are some limitations of this study. It is a cross-sectional study with a small sample size, and most of the patient in our study were on treatment which was not well demarcated. We cannot exclude the possibility of patient selection bias, as our center is a tertiary referral center and as a result majority of the patients were on treatment prior to first presentation. It cannot estimate the true magnitude of the contribution of variables such as disease activity and therapy. A large-scale prospective treatment naïve population study might demonstrate a greater effect over time. Further studies are needed to find out the exact details of the renal involvement in Indian patients with SSc.
| Acknowledgment | | |
Principal, Assam Medical College, Dibrugarh, Assam.
| References | | |
| 1. | Steen VD, Oddis CV, Conte CG, Janoski J, Casterline GZ, Medsger TA Jr. Incidence of systemic sclerosis in Allegheny County, Pennsylvania. A twenty-year study of hospital-diagnosed cases, 1963-1982. Arthritis Rheum 1997;40:441-5.  |
| 2. | Mayes MD, Lacey JV Jr, Beebe-Dimmer J, Gillespie BW, Cooper B, Laing TJ, et al. Prevalence, incidence, survival, and disease characteristics of systemic sclerosis in a large US population. Itis Rheum 2003;48:2246-55. |
| 3. | Hopkinson N. Prevalence of scleroderma in South East England. Rheumatology 2000;S64. [Abstract]. |
| 4. | Allcock RJ, Forrest I, Corris PA, Crook PR, Griffiths ID. A study of the prevalence of systemic sclerosis in northeast England. Rheumatology (Oxford) 2004;43:596-602. |
| 5. | Maricq HR, Weinrich MC, Keil JE, Smith EA, Harper FE, Nussbaum AI, et al. Prevalence of scleroderma spectrum disorders in the general population of South Carolina. Arthritis Rheum 1989;32:998-1006. |
| 6. | Steen VD, Mayes MD, Merkel PA. Assessment of kidney involvement. Clin Exp Rheumatol 2003;21:S29-31. |
| 7. | Steen VD, Medsger TA Jr. Long-term outcomes of scleroderma renal crisis. Ann Intern Med 2000;133:600-3. |
| 8. | Cannon PJ, Hassar M, Case DB, Casarella WJ, Sommers SC, LeRoy EC. The relationship of hypertension and renal failure in scleroderma (progressive systemic sclerosis) to structural and functional abnormalities of the renal cortical circulation. Medicine (Baltimore) 1974;53:1-46. [ PUBMED] |
| 9. | Desai Y, Ghanekar MA, Siquera RD, Joshi VR. Renal involvement in scleroderma. J Assoc Physicians India 1990;38:768-70. |
| 10. | Gupta R, Bammigatti C, Dinda AK, Marwaha V, Gupta S. Prevalence of renal involvement in Indian patients with systemic sclerosis. Indian J Med Sci 2007;61:91-6. [ PUBMED]  |
| 11. | Preliminary criteria for the classification of systemic sclerosis (scleroderma). Subcommittee for scleroderma criteria of the American Rheumatism Association Diagnostic and Therapeutic Criteria Committee. Arthritis Rheum 1980;23:581-90. [ PUBMED] |
| 12. | Sharma VK, Trilokraj T, Khaitan BK, Krishna SM. Profile of systemic sclerosis in a tertiary care center in North India. Indian J Dermatol Venereol Leprol 2006;72:416-20. [ PUBMED] |
| 13. | Laing TJ, Gillespie BW, Toth MB, Mayes MD, Gallavan RH Jr, Burns CJ, et al. Racial differences in scleroderma among women in Michigan. Arthritis Rheum 1997;40:734-42. |
| 14. | Black CM, Denton CP. Scleroderma and related disorders in adults and children. In: Maddison PJ, Isenberg DA, Woo P, Glass DN, editors. Oxford Textbook of Rheumatology. 2 nd ed. Oxford: Oxford Medical Publication; 1998. p. 1217-47. |
| 15. | Maeda M, Matubara K, Hirano H, Watabe H, Ichiki Y, Mori S. Pitting scars in progressive systemic sclerosis. Dermatology 1993;187:104-8. |
| 16. | Ahmed SS, Tan FK. Identification of novel targets in scleroderma: update on population studies, cDNA arrays, SNP analysis, and mutations. Curr Opin Rheumatol 2003;15:766-71. |
| 17. | Baron M, Lee P, Keystone EC. The articular manifestations of progressive systemic sclerosis (scleroderma). Ann Rheum Dis 1982;41:147-52. [ PUBMED] |
| 18. | Wilde AH, Mankin HJ, Rodman GP. Avascular necrosis of the femoral head in scleroderma. Arthritis Rheum 1970;13:445-7. [ PUBMED] |
| 19. | Reveille JD, Fischbach M, McNearney T, Friedman AW, Aguilar MB, Lisse J, et al. Systemic sclerosis in 3 US ethnic groups: a comparison of clinical, sociodemographic, serologic, and immunogenetic determinants. Semin Arthritis Rheum 2001;30:332-46. |
| 20. | Kampschmidt RF, Fupchurch H. Multiple biological effects of a partially purified leucocytes endogenous mediator. Am J Physiol 1973;224:530-3. |
| 21. | Zeng Y, Li M, Xu D, Hou Y, Wang Q, Fang Q, et al. Macrovascular involvement in systemic sclerosis: evidence of correlation with disease activity. Clin Exp Rheumatol 2012;30:S76-80. |
| 22. | Muangchan C, Harding S, Khimdas S, Bonner A, Canadian Scleroderma Research group, Baron M, et al. Association of C-reactive protein with high disease activity in systemic sclerosis: results from the Canadian Scleroderma Research Group. Arthritis Care Res (Hoboken) 2012;64:1405-14. |
| 23. | Ohtsuka T. Relation between elevated high-sensitivity C-reactive protein and anti-mitochondria antibody in patients with systemic sclerosis. J Dermatol 2008;35:70-5. |
| 24. | Ohtsuka T. Serum interleukin-6 level is reflected in elevated high-sensitivity C-reactive protein level in patients with systemic sclerosis. J Dermatol 2010;37:801-6. |
| 25. | Traub YM, Shapiro AP, Rodnan GP, Medsger TA, McDonald RH Jr, Steen VD, et al. Hypertension and renal failure (scleroderma renal crisis) in progressive systemic sclerosis. Review of a 25-year experience with 68 cases. Medicine (Baltimore) 1983;62:335-52. [ PUBMED] |
| 26. | Shapiro AP, Medsger TA Jr. Renal involvement in systemic sclerosis. In: Schrier R, Gottschalk C, editors. Diseases of Kidney. 4 th ed. Boston: Little, Brown; 1988. p. 2272. |
| 27. | Tuffanelli DL, Winkelmann RK. Systemic scleroderma, A clinical study of 727 cases. Arch Dermatol 1961;84:359-71. [ PUBMED] |
| 28. | Steen VD, Syzd A, Johnson JP, Greenberg A, Medsger TA Jr. Kidney disease other than renal crisis in patients with diffuse scleroderma. J Rheumatol 2005;32:649-55. |
| 29. | Ruangjutipopan S, Kasitanon N, Louthrenoo W, Sukitawut W, Wichainun R. Causes of death and poor survival prognostic factors in Thai patients with systemic sclerosis. J Med Assoc Thai 2002;85:1204-9. |
| 30. | Al-Adhadh RN, Al-Sayed TA. Clinical features of systemic sclerosis. Saudi Med J 2001;22:333-6. |
| 31. | Chandrashekharan AN, Krishnamurthy V, Porkodi R. Spectrum of clinical and immunological features of systemic rheumatic diseases in a referral hospital in south India. Progressive systemic sclerosis. J Indian Rheumatol Assoc 1994;2:54-60. |
| 32. | Penn H, Howie AJ, Kingdon EJ, Bunn CC, Stratton RJ, Black CM, et al. Scleroderma renal crisis: patient characteristics and long-term outcomes. QJM 2007;100:485-94. |
| 33. | Steen VD, Costantino JP, Shapiro AP, Medsger TA Jr. Outcome of renal crisis in systemic sclerosis: relation to availability of angiotensin converting enzyme (ACE) inhibitors. Ann Intern Med 1990;113:352-7. |
| 34. | Steen VD, Medsger TA Jr, Osial TA Jr, Ziegler GL, Shapiro AP, Rodnan GP. Factors predicting development of renal involvement in progressive systemic sclerosis. Am J Med 1984;76:779-86. [ PUBMED] |
| 35. | DeMarco PJ, Weisman MH, Seibold JR, Furst DE, Wong WK, Hurwitz EL, et al. Predictors and outcomes of scleroderma renal crisis: the high-dose versus low-dose D-penicillamine in early diffuse systemic sclerosis trial. Arthritis Rheum 2002;46:2983-9. |
| 36. | Teixeira L, Mouthon L, Mahr A, Berezné A, Agard C, Mehrenberger M, et al. Mortality and risk factors of scleroderma renal crisis: a French retrospective study of 50 patients. Ann Rheum Dis 2008;67:110-6. |
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]
|
Search Pubmed for