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| __NOTOC__ | | __NOTOC__ |
| {{IgA nephropathy }} | | {{IgA nephropathy }} |
| {{CMG}} | | {{CMG}}; {{AE}} {{SH}}, {{Rim}} |
| ==Overview== | | ==Overview== |
| ==Clinical Presentation==
| | The majority of patients with IgA nephropathy are asymptomatic. Some patients with IgA nephropathy may develop intermittent gross [[hematuria]] which is often termed as synpharyngitic [[hematuria]], because it occurs after the episodes of [[Bacteria|bacterial]] [[tonsillitis]] or [[Virus|viral]] [[Upper respiratory tract infection|URTI's]]. The patient may also have a positive history of [[flank pain]], [[Low-grade fever|low grade fever]]. |
| IgA nephropathy has a heterogeneous unpredictable clinical course. However, nephritic syndrome with gross hematuria in a young male patient is the most common clinical presentation for IgA nephropathy. Classically, it follows an upper respiratory or gastrointestinal tract infection. The diagnosis of IgA nephropathy is not always obvious clinically; where only 30-40% of patients have such typical presentation.<ref name="pmid15930092">{{cite journal| author=Barratt J, Feehally J| title=IgA nephropathy. | journal=J Am Soc Nephrol | year= 2005 | volume= 16 | issue= 7 | pages= 2088-97 | pmid=15930092 | doi=10.1681/ASN.2005020134 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15930092 }} </ref> In comparison, another 30-40% of patients with IgA nephropathy remain asymptomatic and are only found to have microscopic hematuria.<ref name="pmid15930092">{{cite journal|author=Barratt J, Feehally J| title=IgA nephropathy. | journal=J Am Soc Nephrol | year= 2005 |volume= 16 | issue= 7 | pages= 2088-97 | pmid=15930092 | doi=10.1681/ASN.2005020134 | pmc= |url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15930092 }} </ref> | |
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| Unlike poststreptococcal glomerulonephritis (PSGN), which is also a glomerular disease with similar clinical presentation, IgA nephropathy is called “synpharyngitic” because it typically becomes clinically evident within 2-3 days during the infectious episode vs. PSGN which becomes clinically evident a few weeks after a streptococcal infection.
| | ==History and Symptoms== |
| | *The majority of patients with IgA nephropathy may be asymptomatic. |
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| Adult patients with IgA nephropathy have a less obvious course of disease. The most common presentation of IgA nephropathy among patients of older age groups is microscopic hematuria, proteinuria, and hypertension that might or might not be symptomatic. The presence and intensity of these signs and symptoms vary and may be present in isolation or in combination.<ref name="pmid9596083">{{cite journal| author=Wyatt RJ, Julian BA, Baehler RW, Stafford CC, McMorrow RG, Ferguson T et al.| title=Epidemiology of IgA nephropathy in central and eastern Kentucky for the period 1975 through 1994. Central Kentucky Region of the Southeastern United States IgA Nephropathy DATABANK Project. | journal=J Am Soc Nephrol | year= 1998 | volume= 9 | issue= 5 | pages= 853-8 | pmid=9596083 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9596083 }} </ref><ref name="pmid9048338">{{cite journal| author=Radford MG, Donadio JV, Bergstralh EJ, Grande JP| title=Predicting renal outcome in IgA nephropathy. | journal=J Am Soc Nephrol | year= 1997 | volume= 8 | issue= 2 | pages= 199-207 | pmid=9048338 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9048338 }} </ref>
| | ===History=== |
| | Patients with IgA nephropathy may have a positive history of:<ref name="pmid7723227">{{cite journal |vauthors=Galla JH |title=IgA nephropathy |journal=Kidney Int. |volume=47 |issue=2 |pages=377–87 |date=February 1995 |pmid=7723227 |doi= |url=}}</ref><ref name="pmid12213946">{{cite journal |vauthors=Donadio JV, Grande JP |title=IgA nephropathy |journal=N. Engl. J. Med. |volume=347 |issue=10 |pages=738–48 |date=September 2002 |pmid=12213946 |doi=10.1056/NEJMra020109 |url=}}</ref> |
| | *Intermittent gross [[hematuria]] |
| | *Synpharyngitic [[hematuria]] |
| | *The precipitating factors for synpharyngitic hematuria are: |
| | **[[Bacteria|Bacterial]] [[tonsillitis]] |
| | **[[Virus|Viral]] [[Upper respiratory tract infection|URTI's]] |
| | *[[Microscopic hematuria]] |
| | *[[Flank pain]] |
| | *[[Low-grade fever|Low grade fever]] |
| | *Mild [[proteinuria]] |
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| Only 10% of patients with IgA nephropathy present with nephrotic syndrome; usually these patients have pathological findings of minimal-change disease on biopsy.<ref name="pmid23782179">{{cite journal| author=Wyatt RJ, Julian BA| title=IgA nephropathy. | journal=N Engl J Med | year= 2013 | volume= 368 | issue= 25 | pages= 2402-14 | pmid=23782179 | doi=10.1056/NEJMra1206793 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23782179 }} </ref> Finally, only 10% of the patients with IgA nephropathy present with renal failure at diagnosis.
| | ===Common Symptoms=== |
| | Common symptoms of IgA nephropathy include:<ref name="pmid15524056">{{cite journal |vauthors=Hall CL, Bradley R, Kerr A, Attoti R, Peat D |title=Clinical value of renal biopsy in patients with asymptomatic microscopic hematuria with and without low-grade proteinuria |journal=Clin. Nephrol. |volume=62 |issue=4 |pages=267–72 |date=October 2004 |pmid=15524056 |doi= |url=}}</ref><ref name="pmid8041865">{{cite journal |vauthors=Topham PS, Harper SJ, Furness PN, Harris KP, Walls J, Feehally J |title=Glomerular disease as a cause of isolated microscopic haematuria |journal=Q. J. Med. |volume=87 |issue=6 |pages=329–35 |date=June 1994 |pmid=8041865 |doi= |url=}}</ref> |
| | *[[Flank pain]] |
| | *[[Low-grade fever|Low grade fever]] |
| | *Mild [[proteinuria]] |
| | *[[Microscopic hematuria]] |
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| ==Diagnosis== | | ===Less Common Symptoms=== |
| ===Kidney Biopsy===
| | Less common symptoms of IgA nephropathy include: <ref name="GutierrezGonzalez2006">{{cite journal|last1=Gutierrez|first1=E.|last2=Gonzalez|first2=E.|last3=Hernandez|first3=E.|last4=Morales|first4=E.|last5=Martinez|first5=M. A.|last6=Usera|first6=G.|last7=Praga|first7=M.|title=Factors That Determine an Incomplete Recovery of Renal Function in Macrohematuria-Induced Acute Renal Failure of IgA Nephropathy|journal=Clinical Journal of the American Society of Nephrology|volume=2|issue=1|year=2006|pages=51–57|issn=1555-9041|doi=10.2215/CJN.02670706}}</ref> |
| Immunofluorescence microscopy is required for the diagnosis of IgA nephropathy. IgA nephropathy histopathological findings may vary among individuals and with disease progression. The histopathological hallmark of IgA nephropathy is the predominant presence of mesangial stains for IgA in comparison to the much less intense stains for IgG or C3. IgA1 deposits may be present anywhere along the mesangium, and even in the glomerular capillary wall.
| | *[[Acute (medicine)|Acute]] [[rapidly progressive glomerulonephritis]] |
| | | **[[Edema]] |
| IgA nephropathy may have any of the following 6 findings on light microscopy ''(in increasing order of severity''): | | **[[Hypertension]] |
| | | **[[Renal insufficiency]] |
| # '''Normal appearing biopsy'''
| | **[[Hematuria]] |
| # '''Focal mesangial hypercellularity'''
| | *[[Oliguria]] |
| #'''Diffuse mesangial hypercellularity'''
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| #'''Focal proliferative glomerulonephritis''' ''(most common finding on diagnostic biopsy)''
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| # '''Diffuse proliferative glomerulonephritis'''
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| # '''Chronic sclerosing glomerulonephritis'''
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| On electron microscopy, mesangial deposits are most commonly seen. However, depositions on capillary walls are possible; they herald worse prognosis.
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| The following variations may also be found; but they are not exclusive of IgA nephropathy<ref name="pmid23782179">{{cite journal| author=Wyatt RJ, Julian BA| title=IgA nephropathy. | journal=N Engl J Med | year= 2013 | volume= 368 | issue= 25 | pages= 2402-14 | pmid=23782179 | doi=10.1056/NEJMra1206793 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23782179 }} </ref>:
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| *Segmental endocapillary proliferation
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| *Segmental Glomerulosclerosis and adhesions
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| *Tubular atrophy and interstitial fibrosis
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| *Glomerular crescent surrounding the glomerular tuft
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| ===Serum Galactose-Deficient IgA1 Levels===
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| Although IgA1 levels are almost always elevated in patients with IgA nephropathy and seem to be a promising technique for diagnostic purposes, the sensitivity and specificity for lectin-based assays to determine galactose-deficient IgA1 levels are not yet sufficiently evaluated.<ref name="pmid17342176">{{cite journal| author=Moldoveanu Z, Wyatt RJ, Lee JY, Tomana M, Julian BA, Mestecky J et al.| title=Patients with IgA nephropathy have increased serum galactose-deficient IgA1 levels. | journal=Kidney Int | year= 2007 | volume= 71 | issue= 11 | pages= 1148-54 | pmid=17342176 | doi=10.1038/sj.ki.5002185 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17342176 }} </ref><ref name="pmid23782179">{{cite journal| author=Wyatt RJ, Julian BA| title=IgA nephropathy. | journal=N Engl J Med | year= 2013 | volume= 368 | issue= 25 | pages= 2402-14 | pmid=23782179 | doi=10.1056/NEJMra1206793 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23782179 }} </ref>
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| According to Moldoveanu et al.<ref name="pmid17342176">{{cite journal| author=Moldoveanu Z, Wyatt RJ, Lee JY, Tomana M, Julian BA, Mestecky J et al.| title=Patients with IgA nephropathy have increased serum galactose-deficient IgA1 levels. | journal=Kidney Int | year= 2007 | volume= 71 | issue= 11 | pages= 1148-54 | pmid=17342176 | doi=10.1038/sj.ki.5002185 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17342176 }} </ref>, the sensitivity of serum IgA1 levels is 76.5% and the specificity is 94%, with an 88.6% positive predictive value and a 78.9% negative predictive value for the diagnosis of IgA nephropathy. They studied 153 patients in total and determined the upper normal limit to be 1076 U/ml for diagnosis. Of note, however, the study utilized a 90th percentile for statistical significance. Ultimately, renal biopsy is still considered the only diagnostic approach for IgA nephropathy.
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| ===Urinary Proteeomic Analysis===
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| Urinary proteomic analysis of samples using capillary electrophoresis coupled with mass spectrometry (CE-MS) allows to accurately evaluate up to urinary 2000 polypeptides using “total protein/peptide” different unique patterns, each corresponding to different pathology.<ref name="pmid14604118">{{cite journal| author=Wittke S, Fliser D, Haubitz M, Bartel S, Krebs R, Hausadel F et al.| title=Determination of peptides and proteins in human urine with capillary electrophoresis-mass spectrometry, a suitable tool for the establishment of new diagnostic markers. | journal=J Chromatogr A | year= 2003 | volume= 1013 | issue= 1-2 | pages= 173-81 | pmid=14604118 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14604118 }} </ref> CE-MS has been studied to provide a fast and accurate diagnosis of IgA nephropathy by utilizing specific polypeptide patterns in urinary samples of patients with IgA nephropathy.<ref name="pmid15882273">{{cite journal| author=Haubitz M, Wittke S, Weissinger EM, Walden M, Rupprecht HD, Floege J et al.| title=Urine protein patterns can serve as diagnostic tools in patients with IgA nephropathy. | journal=Kidney Int | year= 2005 | volume= 67 | issue= 6 | pages= 2313-20 | pmid=15882273 | doi=10.1111/j.1523-1755.2005.00335.x | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15882273 }} </ref>
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| When compared to urinary samples of 57 healthy subjects and 57 patients with membranous nephropathy, CE-MS showed a sensitivity of 100% and 77%, respectively, and a specificity of 90% and 100%, respectively.<ref name="pmid15882273">{{cite journal| author=Haubitz M, Wittke S, Weissinger EM, Walden M, Rupprecht HD, Floege J et al.| title=Urine protein patterns can serve as diagnostic tools in patients with IgA nephropathy. | journal=Kidney Int | year= 2005 | volume= 67 | issue= 6 | pages= 2313-20 | pmid=15882273 | doi=10.1111/j.1523-1755.2005.00335.x | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15882273 }} </ref> Urinary proteomic analysis may be a promising novel technique, but it requires further evaluation before it replaces a kidney biopsy for the diagnosis of IgA nephropathy.
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| ==References== | | ==References== |
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| {{WH}} | | {{WH}} |
| {{WS}} | | {{WS}} |
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| [[Category:Nephrology]] | | [[Category:Nephrology]] |
| [[Category:Genetic disorders]] | | [[Category:Genetic disorders]] |