Introduction
Overview
Classifying Renal Disease in Scleroderma
Domain |
---|
Blood pressure |
Acute increase in blood pressure defined as any of the following: |
- Systolic blood pressure ≥ 140 mm Hg |
- Diastolic blood pressure ≥ 90 mm Hg |
- An increase in systolic blood pressure of ≥ 30 mm Hg above normal |
- An increase in diastolic blood pressure of ≥ 20 mm Hg above normal |
Blood pressure measurement should be taken twice, separated by at least 5 min; if blood pressure readings are discordant, repeat readings should be taken until 2 consistent readings are obtained |
Kidney injury [75] |
AKI defined as any of the following: |
- Increase in serum creatinine of ≥ 26.5 μmoles/l (≥ 0.3 mg/dl) within 48 h |
- Increase in serum creatinine to ≥ 1.5 times baseline, which is known or presumed to have occurred within the prior 7 days |
- Urine volume < 0.5 ml/kg/h for 6 h |
MAHA and thrombocytopenia |
New or worsening anaemia not due to other causes |
Schistocytes or other red blood cell fragments on blood smear |
Thrombocytopenia ≤ 100,000 platelets/mm3, confirmed by manual smear |
Laboratory evidence of haemolysis, including elevated lactate dehydrogenase, reticulocytosis, and/or low or absent haptoglobin |
A negative direct antiglobulin test |
Target organ dysfunction |
Hypertensive retinopathy (haemorrhages, hard and soft [cottonwool] exudates, and/or disc oedema, not attributable to other causes), confirmed by an ophthalmologist |
Hypertensive encephalopathy, characterized by headache, altered mental status, seizures, visual disturbances, and/or other focal or diffuse neurologic signs not attributable to other causes |
Acute heart failure, characterized by typical symptoms (e.g., breathlessness, ankle swelling, and fatigue) that may be accompanied by signs (e.g., elevated jugular venous pressure, pulmonary crackles, and peripheral oedema) |
Acute pericarditis, diagnosed with at least 2 of the 4 following criteria: (1) pericarditis chest pain, (2) pericardial rub, (3) new widespread ST segment elevation or PR segment depression on electrocardiography, and (4) pericardial effusion (new or worsening) on cardiac echocardiography |
Renal histopathology |
Histopathologic findings on kidney biopsy consistent with SRC, which may include the following: |
- Small vessel (arcuate and interlobular arteries) changes that predominate over glomerular alterations |
- Glomerular changes of thrombotic microangiopathy may be present, with acute changes including fibrin thrombi and endothelial swelling, red blood cell fragments, and mesangiolysis, and chronic changes including double contours of the glomerular basement membrane |
- Nonspecific ischemic changes with corrugation of the glomerular basement membrane, and even segmental or global sclerosis of glomeruli may occur |
- Early vascular abnormalities include intimal accumulation of myxoid material, thrombosis, fibrinoid necrosis, and fragmented red blood cells, sometimes resulting in cortical necrosis |
- Narrowing and obliteration of the vascular lumen lead to glomerular ischemia. Juxtaglomerular apparatus hyperplasia, while relatively rare (10%), can be observed |
- Late changes are manifested by intimal thickening and proliferation (which lead to characteristic vascular ‘onion-skin’ lesions), glomerulosclerosis, and interstitial fibrosis |
- Nonspecific tubular changes may also occur, including acute tubular injury in the early stage of injury, and later interstitial fibrosis and tubular atrophy. Since none of these findings is specific for SRC, the pathologic diagnosis must be supported by appropriate clinical and serologic data |
Epidemiology
Pathogenesis
Renal Biopsy Abnormalities
Complement
Endothelin
Biomarkers
Animal Models of SRC
Emerging
Risk Factors
Scleroderma-Specific Antibodies
Genetic Factors
Clinical Risk Factors
p value | OR | HR | CI | Study | |
---|---|---|---|---|---|
anti-RNA pol III | < 0.001 | 5.86 | [2.6–13.2] | Moinzadeh et al. 2020a | |
Chronic kidney disease | < 0.004 | 2.5 | [1.34–4.6] | ||
< 0.001 | 20.7 | [2.2–190.7] | Gordon et al. 2019b | ||
Proteinuria | < 0.001 | 183 | [19.1–1750] | ||
< 0.001 | 5.55 | [3.4–8.9] | Moinzadeh et al. 2020a | ||
DcSSc vs. LcSSc | 0.002 | 2.54 | [1.42–4.5] | ||
DLCO | < 0.001 | 4.41 | [2.01–9.6] | ||
Glucocorticoid use | 0.007 | 1.93 | [1.20–3.1] | ||
0.014 | 3.63 | [1.30–10.05] | De Marco et al. 2002c | ||
0.49 | 1.32 | [0.60–2.87] | Butikofer et al. 2020d | ||
Hypertension | 0.002 | 2.22 | [1.34–3.6] | ||
< 0.001 | 13.1 | [4.7–36.6] | Gordon et al. 2019b | ||
mRSS > 14 | 3.08 | [1.24–7.61] | Avouac et al. 2016e | ||
0.003 | 10 | [2.21–45.9] | De Marco et al. 2002c | ||
ACE inhibitors | 0.003 | 2.07 | [1.28–3.36] | Butikofer et al. 2020d | |
Tendon friction rub | 0.15 | 1.7 | [0.83–3.48] | ||
0.0007 | 2.33 | [1.03–6.19] | Avouac et al. 2016e | ||
Large joint contracture | 0.008 | 16.12 | [2.07–125.2] | De Marco et al. 2002c | |
Heart involvement | 0.048 | 2.93 | [1.01–8.4] |
Outcomes
The Role of ACEi
Clinical Presentation
Diagnosis
Diagnostic criteria (essential) |
---|
New onset BP > 150/85 mmHg or obtained at least twice over 24 h |
Increase ≥ 20 mmHg from usual systolic BP |
Acute kidney injury stage 1 or higher: |
(> 50% increase in serum creatinine from stable baseline or an absolute increase of 26.5 µmol/L) |
Supportive evidence (desirable) |
---|
MAHA on blood film, thrombocytopaenia and other biochemical findings consistent with haemolysis |
Findings consistent with accelerated hypertension on retinal examination |
Microscopic haematuria on urine dipstick and/or red blood cells on urine microscopy |
Oliguria or anuria |
Renal biopsy with typical features of SRC including onion skin proliferation within the walls of intrarenal arteries and arterioles, fibrinoid necrosis, glomerular shrinkage |
Flash pulmonary oedema |
Spectrum of Renal Disease
Serum markers | Urinalysis | Typical presentation | Patient cohort | Histopathology | |
---|---|---|---|---|---|
Scleroderma renal crisis (SRC) | Creatine increased AKI (150% typical) Anaemia (MAHA) Thrombocytopenia Haemolysis Negative DAT | Mild proteinuria (< 2 g/day)and haematuria May be urinary casts | Systolic blood pressure ≥ 140 mm Hg Diastolic blood pressure ≥ 90 mm Hg Acute | Early, diffuse SSc Anti-ARA antibody positive High dose glucocorticoid, tendon friction rub | Glomerular or extraglomerular TMA changes, rarely Juxtaglomerulus hyperplasia. Chronic ‘onion skin’ appearance [22] |
Thrombotic microangiopathies (TMA) (causes other than SSC) | AKI MAHA (thrombocytopenia and reticularcytosis, increased LDH and low haptoglobin) ADAMS-13 < 10% activity [78] | Proteinuria haematuria | Fever Haemorrhagic manifestation, confusion, neurological deficit Acute | May occur as part of SRC In adults, often underlying comorbid cause. TTP less likely to see AKI | Intravascular fibrin thrombi with mucoid changes. Intimal proliferation of arterioles. Duplication of GBM with endocapillary hypercellularity |
ANCA-associated glomerular nephritis | AKI ANCA (MPO/PR3) positive Eosinophilia Thrombophilia Elevated CRP | Proteinuria (often > 3 g/day) and Haematuria likely significant | Vasculitic rash, pulmonary lesions, peripheral neuropathy, fatigue, weight loss Acute/chronic | > 50 years old MPA, GPA, EGPA, RLV | Pauci immune necrotising glomerulonephritis; focal, crescentic, sclerotic or mixed [79] |
SLE-associated glomerular nephritis | AKI possible but not diagnostic dsDNA, anti-Smith Low complement (C3) | Proteinuria (> 4 g/day worst prognosis [80]) in 100%, microscopic haematuria in 80% [81] | Known lupus or new features of disease. Possible nephrotic syndrome, 30% hypertension Acute/chronic | Early disease, increased risk in black patients, male patients |