Systemic lupus erythematosus (SLE) is a diagnosis that must be based on
the proper constellation of clinical findings and laboratory evidence.
Familiarity with the diagnostic criteria helps clinicians to recognize SLE
and to subclassify this complex disease based on the pattern of
target-organ manifestations.
The 1982 American College of Rheumatology (ACR) criteria summarize
features necessary to diagnose SLE.20, 21 They are summarized below with a
useful mnemonic. The presence of 4 of the 11 criteria yields a sensitivity
of 85% and a specificity of 95% for SLE. Keep in mind that individual
features are variably sensitive and specific. Patients with SLE may
present with any combination of clinical features and serologic evidence
of lupus. The following is the ACR diagnostic criteria in SLE, presented
in the "SOAP BRAIN MD" acronym:
* Serositis - Pleurisy, pericarditis on examination or diagnostic ECG
or imaging
* Oral ulcers - Oral or nasopharyngeal, usually painless; palate is
most specific
* Arthritis - Nonerosive, two or more peripheral joints with
tenderness or swelling
* Photosensitivity - Unusual skin reaction to light exposure
* Blood disorders - Leukopenia (<4000 cells 103/µL on more than one
occasion), lymphopenia (<1500 cells/µL on more than one occasion),
thrombocytopenia (<100 X103/µL in the absence of offending medications),
hemolytic anemia
* Renal involvement - Proteinuria (>0.5 g/d or 3+ positive on dipstick
testing) or cellular casts
* ANAs - Higher titers generally more specific (>1:160); must be in
the absence of medications associated with drug-induced lupus
* Immunologic phenomena - dsDNA; anti-Smith (Sm) antibodies;
antiphospholipid antibodies (anticardiolipin immunoglobulin G [IgG] or
immunoglobulin M [IgM] or lupus anticoagulant); biologic false-positive
serologic test results for syphilis, lupus erythematosus (LE) cells
(omitted in 1997)
* Neurologic disorder - Seizures or psychosis in the absence of other
causes
* Malar rash - Fixed erythema over the cheeks and nasal bridge, flat
or raised
* Discoid rash - Erythematous raised-rimmed lesions with keratotic
scaling and follicular plugging, often scarring
In patients with high clinical suspicion or high ANA titers, additional
testing is indicated. This commonly includes evaluation of antibodies to
dsDNA, complement, and ANA subtypes such as Sm, SSA, SSB, and
ribonucleoprotein (RNP) (often called the ENA panel). Screening laboratory
studies to diagnose possible SLE should include a CBC count with
differential, serum creatinine, urinalysis with microscopy, ANA, and,
perhaps, basic inflammatory markers. The following are autoantibody tests
used in the diagnosis of SLE:22
* ANA - Screening test; sensitivity 95%; not diagnostic without
clinical features
* Anti-dsDNA - High specificity; sensitivity only 70%; level variable
based on disease activity
* Anti-Sm - Most specific antibody for SLE; only 30-40% sensitivity
* Anti-SSA (Ro) or Anti-SSB (La) - Present in 15% of patients with SLE
and other connective-tissue diseases such as Sjögren syndrome; associated
with neonatal lupus
* Anti-ribosomal P - Uncommon antibodies that may correlate with lupus
cerebritis
* Anti-RNP - Included with anti-Sm, SSA, and SSB in the ENA profile;
may indicate mixed connective-tissue disease with overlap SLE,
scleroderma, and myositis
* Anticardiolipin - IgG/IgM variants measured with enzyme-linked
immunoassay (ELISA) among the antiphospholipid antibodies used to screen
for antiphospholipid antibody syndrome
* Lupus anticoagulant - Multiple tests (eg, Direct Russell Viper Venom
test) to screen for inhibitors in the clotting cascade in antiphospholipid
antibody syndrome
* Coombs test - Coombs test–positive anemia to denote antibodies on
RBCs
* Anti-histone - Drug-induced lupus ANA antibodies often this type
(eg, with procainamide or hydralazine; perinuclear antineutrophil
cytoplasmic antibody [p-ANCA]–positive in minocycline-induced drug-induced
lupus)
Other laboratory tests used in the diagnosis of SLE include the following:
* Inflammatory markers: Levels of inflammatory markers, including the
erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP), may be
elevated in any inflammatory condition, including SLE. CRP levels change
more acutely, and the ESR lags behind disease changes.
* Complement levels: C3 and C4 levels are often depressed in patients
with active SLE because of consumption by immune complex–induced
inflammation. In addition, some patients have congenital complement
deficiency that predisposes them to SLE.
* A CBC count may help to screen for leukopenia, lymphopenia, anemia,
and thrombocytopenia, and urinalysis and creatinine studies may be useful
to screen for kidney disease.
* Liver test results may be mildly elevated in acute SLE or in
response to therapies such as azathioprine or nonsteroidal
anti-inflammatory drugs (NSAIDS).
* Creatinine kinase levels may be elevated in myositis or overlap
syndromes.
Imaging Studies
* Joint radiography often provides little evidence of SLE given the
absence of erosions, even in the presence of Jaccoud arthropathy with
deformity or subluxations. The most common radiographic changes in SLE
include periarticular osteopenia and soft-tissue swelling.
* Chest radiography and chest CT scanning can be used to monitor
interstitial lung disease and to assess for pneumonitis, pulmonary emboli,
and alveolar hemorrhage.
* Brain MRI/magnetic resonance angiography (MRA) is used to evaluate
CNS lupus for white-matter changes, vasculitis, or stroke, although
findings are often nonspecific.
* Echocardiography is used to assess for pericardial effusion,
pulmonary hypertension, or verrucous Libman-Sacks endocarditis.
Procedures
* Lumbar puncture may be performed to exclude infection with fever or
neurologic symptoms. Nonspecific elevations in cell count and protein
level and decrease in glucose level may be found in the cerebrospinal
fluid of patients with CNS lupus.
* Renal biopsy is used to identify the specific type of
glomerulonephritis, to aid in prognosis, and to guide treatment. Another
benefit of renal biopsy is in distinguishing renal lupus from renal
thrombosis, which may complicate antiphospholipid antibody syndrome and
require anticoagulation rather than immunomodulatory therapy.
* Skin biopsy can help to diagnose SLE or unusual rashes in patients
with SLE. Many different rashes may herald SLE, making review by a
dermatopathologist important.
Histologic Findings
Renal biopsy is used to confirm the presence of lupus nephritis, to aid in
classification of SLE nephritis, and to guide therapeutic decisions. The
World Health Organization classification for lupus nephritis is based on
light microscopy, electron microscopy, and immunofluorescence findings.
International Society of Nephrology 2003 Revised Classification of SLE
Nephritis23
Class Classification Features
Class I
Minimal mesangial
Normal light microscopy findings; abnormal electron microscopy findings
Class II
Mesangial proliferative
Hypercellular on light microscopy
Class III
Focal proliferative
<50% of glomeruli involved
Class IV
Diffuse proliferative
>50% of glomeruli involved; classified segmental or global; treated
aggressively
Class V
Membranous
Predominantly nephrotic disease
Class VI
Advanced sclerosing
Chronic lesions and sclerosis
Lupus skin rash often demonstrates inflammatory infiltrates at the
dermoepidermal junction and vacuolar change in the basal columnar cells.
Discoid lesions demonstrate more-significant skin inflammation, with
hyperkeratosis, follicular plugging, edema, and mononuclear cell
infiltration at the dermoepidermal junction. In many SLE rashes,
immunofluorescent stains demonstrate immunoglobulin and complement
deposits at the dermoepidermal basement membrane.
Wednesday, September 8, 2010
Sunday, August 22, 2010
Pretest probability of HIT (the 4 T's)
Thrombocytopenia —
Platelet count fall >50 percent and nadir >20,000: 2 points
Platelet count fall 30 to 50 percent or nadir 10 to 19,000: 1 points
Platelet count fall <30 percent or nadir <10,000: zero points
Timing of platelet count fall —
Clear onset between days 5 and 10 or platelet count fall at ≤1 day if prior heparin exposure within the last 30 days: 2 points
Consistent with fall at 5 to 10 days but not clear (eg, missing platelet counts) or onset after day 10 or fall ≤1 day with prior heparin exposure within the last 30 to 100 days: 1 point
Platelet count fall at <4 days without recent exposure: 0 points
Thrombosis or other sequelae —
Confirmed new thrombosis, skin necrosis, or acute systemic reaction after intravenous unfractionated heparin bolus: 2 points
Progressive or recurrent thrombosis, non-necrotizing (erythematous) skin lesions, or suspected thrombosis which has not been proven: 1 point
None: zero points
Other causes for thrombocytopenia present —
None apparent: 2 points
Possible: 1 point
Definite: zero points
Test interpretation — A score is determined for each of the four above categories, resulting in a total score from zero to 8. Pretest probabilities for HIT are, as follows:
zero to 3: Low probability
4 to 5: Intermediate probability
6 to 8: High probability
Among 111 patients with a low pretest probability of HIT using this scoring system, only one had clinically significant HIT antibodies (0.9 percent). In contrast, the overall rate of clinically significant HIT antibodies was 11.4 and 34 percent in those with intermediate and high scores, respectively.
A significant concern with these findings is that there was substantial variability in the rate of clinically significant HIT antibodies at the two centers in patients with intermediate (29 versus 8 percent) or high scores (100 versus 21 percent). A number of methodologic and center-specific factors may have contributed to these differences [119].
These initial results were confirmed at two other centers, in which the incidences of a positive rapid ELISA immunoassay for HIT antibodies were 1.6 and 4 percent and that of a positive serotonin release assay or HIPA assay was zero percent for a total of 458 patients with suspected HIT and a low probability on the 4 T's test [108,120].
Accordingly, laboratory testing for HIT might reasonably be limited to patients with an intermediate or high pretest probability, since those with a low pretest probability are at very low risk of having clinically significant HIT antibodies (ie, <5 percent) [7,108,120].
Platelet count fall >50 percent and nadir >20,000: 2 points
Platelet count fall 30 to 50 percent or nadir 10 to 19,000: 1 points
Platelet count fall <30 percent or nadir <10,000: zero points
Timing of platelet count fall —
Clear onset between days 5 and 10 or platelet count fall at ≤1 day if prior heparin exposure within the last 30 days: 2 points
Consistent with fall at 5 to 10 days but not clear (eg, missing platelet counts) or onset after day 10 or fall ≤1 day with prior heparin exposure within the last 30 to 100 days: 1 point
Platelet count fall at <4 days without recent exposure: 0 points
Thrombosis or other sequelae —
Confirmed new thrombosis, skin necrosis, or acute systemic reaction after intravenous unfractionated heparin bolus: 2 points
Progressive or recurrent thrombosis, non-necrotizing (erythematous) skin lesions, or suspected thrombosis which has not been proven: 1 point
None: zero points
Other causes for thrombocytopenia present —
None apparent: 2 points
Possible: 1 point
Definite: zero points
Test interpretation — A score is determined for each of the four above categories, resulting in a total score from zero to 8. Pretest probabilities for HIT are, as follows:
zero to 3: Low probability
4 to 5: Intermediate probability
6 to 8: High probability
Among 111 patients with a low pretest probability of HIT using this scoring system, only one had clinically significant HIT antibodies (0.9 percent). In contrast, the overall rate of clinically significant HIT antibodies was 11.4 and 34 percent in those with intermediate and high scores, respectively.
A significant concern with these findings is that there was substantial variability in the rate of clinically significant HIT antibodies at the two centers in patients with intermediate (29 versus 8 percent) or high scores (100 versus 21 percent). A number of methodologic and center-specific factors may have contributed to these differences [119].
These initial results were confirmed at two other centers, in which the incidences of a positive rapid ELISA immunoassay for HIT antibodies were 1.6 and 4 percent and that of a positive serotonin release assay or HIPA assay was zero percent for a total of 458 patients with suspected HIT and a low probability on the 4 T's test [108,120].
Accordingly, laboratory testing for HIT might reasonably be limited to patients with an intermediate or high pretest probability, since those with a low pretest probability are at very low risk of having clinically significant HIT antibodies (ie, <5 percent) [7,108,120].
Friday, March 12, 2010
The Great Prostate Mistake
OP-ED CONTRIBUTOR
By RICHARD J. ABLIN
Published: March 10, 2010
Americans waste an enormous amount of money on an inaccurate test for prostate cancer.
Friday, January 8, 2010
PCP Treatment
Drugs used in the treatment of pneumocystis carinii pneumonia
TMP-SMX (mild-severe)
TMP: 15-20 mg/kg/day
SMX: 75-100 mg/kg/day
PO or IV divided into 3 or 4 doses per day
Adverse reactions:Rash, fever, neutropenia, hyperkalemia, transaminase elevation
Adjunctive glucocorticoids *
(* Adjunctive glucocorticoids should be given to patients with a room air PA02 =70 mmHg or alveolar-arterial oxygen gradient >/=35 mmHg.)
Prednisone:
40 mg PO twice daily for 5 days
40 mg PO once daily for 5 days
20 mg PO once daily for 11 days
Adverse reactions: Hyperglycemia, hypertension, reactivation of herpetic lesions, ? increased susceptibility to other infections
Pentamidine (moderate-severe)
4 mg/kg/day IV once daily
Adverse reaction: Nephrotoxicity, hyperkalemia, hypoglycemia, hypotension, pancreatitis, dysrhythmias, transaminase elevation
Atovaquone (mild-moderate)
750 mg PO twice daily
Adverse reaction: Rash, fever, transaminase elevation
TMP plus dapsone (mild-moderate)
TMP: 5 mg/kg PO three times daily
Dapsone: 100 mg/day PO once daily
Adverse Reaction; Trimethoprim: Rash, gastrointestinal distress, transaminase elevation, neutropenia
Dapsone: Rash, fever, gastrointestinal upset, methemoglobinemia, hemolytic anemia, (check for G6PD deficiency)
Primaquine plus clindamycin (mild-severe)
Primaquine: 15-30 mg/day PO once daily
Clindamycin: 600 mg IV every 8 hours OR 300-450 mg PO four times daily
Adverse Reactions: Primaquine: Rash, fever, methemoglobinemia, hemolytic anemia (check for G6PD deficiency)
Clindamycin: Rash, diarrhea, Clostridium difficile colitis, abdominal pain
TMP-SMX (mild-severe)
TMP: 15-20 mg/kg/day
SMX: 75-100 mg/kg/day
PO or IV divided into 3 or 4 doses per day
Adverse reactions:Rash, fever, neutropenia, hyperkalemia, transaminase elevation
Adjunctive glucocorticoids *
(* Adjunctive glucocorticoids should be given to patients with a room air PA02 =70 mmHg or alveolar-arterial oxygen gradient >/=35 mmHg.)
Prednisone:
40 mg PO twice daily for 5 days
40 mg PO once daily for 5 days
20 mg PO once daily for 11 days
Adverse reactions: Hyperglycemia, hypertension, reactivation of herpetic lesions, ? increased susceptibility to other infections
Pentamidine (moderate-severe)
4 mg/kg/day IV once daily
Adverse reaction: Nephrotoxicity, hyperkalemia, hypoglycemia, hypotension, pancreatitis, dysrhythmias, transaminase elevation
Atovaquone (mild-moderate)
750 mg PO twice daily
Adverse reaction: Rash, fever, transaminase elevation
TMP plus dapsone (mild-moderate)
TMP: 5 mg/kg PO three times daily
Dapsone: 100 mg/day PO once daily
Adverse Reaction; Trimethoprim: Rash, gastrointestinal distress, transaminase elevation, neutropenia
Dapsone: Rash, fever, gastrointestinal upset, methemoglobinemia, hemolytic anemia, (check for G6PD deficiency)
Primaquine plus clindamycin (mild-severe)
Primaquine: 15-30 mg/day PO once daily
Clindamycin: 600 mg IV every 8 hours OR 300-450 mg PO four times daily
Adverse Reactions: Primaquine: Rash, fever, methemoglobinemia, hemolytic anemia (check for G6PD deficiency)
Clindamycin: Rash, diarrhea, Clostridium difficile colitis, abdominal pain
Hepatic Encephalopathy
Major causes of hepatic encephalopathy
- GI bleeding
- Portal Vein Thrombosis
- Infection/Shock
- TIPS
- No lactulose
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