<prompt> Most common pulmonary manifestation of SLE:Shrinking LungPleuritisIntra alveolar hemorrhage.Interstitial inflammation  <response>: Ans. b PleuritisRef: Harrisons Principle of Internal Medicine 20th Ed; Page No- 2520Most Common Complication in SLE Cutaneous Manifestations: The most common acute SLE rash: Butterfly rash Most common chronic dermatitis in lupus: Discoid lupus erythematosus DLE Vascular Occlusions: Myocardial infarctions are primarily manifestations of accelerated atherosclerosis. Pulmonary manifestation: Pleuritis with or without pleural effusion. Cardiac manifestations: Pericarditis. Hematologic Manifestations: Anemia Renal Manifestations: Nephritis CNS Manifestations: The most common manifestation of diffuse CNS lupus is cognitive dysfunction, including difficulties with memory and reasoning.NoteOther pulmonary Complications Pulmonary infiltrates are seen active SLE and it is very difficult to distinguish from infection on imaging studies. Interstitial inflammation is a life-threatening pulmonary manifestation leading to fibrosis, shrinking lung syndrome, and intra-alveolar hemorrhage. Pulmonary arterial hypertension occurs in a small proportion of SLE patients.Cardiac complications More serious cardiac manifestations are myocarditis and fibrinous endocarditis of Libman-Sacks. A patient has SLE if four or more of these 11 criteria are present at any time.Diagnostic criteria for SLEMucocutaneous signs each counts as one Malar rash Photosensitivity rash Oral ulcers rash Discoid rashArthritisPresent in 90 percent of patients; non-erosiveCardiac PulmonaryPericarditis, myocarditis, Pleuritis most common pulmonary finding, pleural effusion, pneumonitis, pulmonary HypertensionHematologic Any blood involvement counts as 1 criteriaHemolytic anemia, leukopenia, lymphopenia, thrombocytopeniaRenalIt benign from Proteinuria 0.5g day to end stage renal disease; such as:- Cellular casts, Glomerulonephritis, azotemia, pyuria, uremia, HTNCerebralSeizures, psychosis may be subtle, meningitis TIA, cerebrovascular accidentSerology ANA. It is 95 sensitive but not specific; almost all patients with SLE have elevated serum ANA levels. Anti-ds DNA 60-70 or anti-Sm Smith 10-20. The presence of either of these is diagnostic of SLE--very specific but obviously not sensitiveNoteEach of the serologic abnormalities counts as 1 criterion. Hence, if the person has joint pain, a rash, and both an ANA and DS DNA, that patient would have 4 criteria.Points to RememberDiagnostic Test for SLE Best initial test: ANA Most specific test: Anti-DS DNA 60-70 or anti-Sm Smith 10-20.. Rule of thumb- ANA positivity is a must in SLE diagnosis. ANA negativity twice rules out SLE. Even though ANA positivity cannot confirm SLE - negativity can rule out.Note There is no ANA negative SLE. But there is ANA negative scleroderma Also Drug induced lupus - secondary to Quinidine Minocycline tends to be ANA negative. 