Hypocomplementemia is also seen, due to either consumption of C3 and C4 by immune complex-induced inflammation or to congenitally complement deficiency, which may predispose to SLE. Renal disorder: More than 0.5 g per day protein in urine or cellular casts seen in urine under a microscope; sensitivity = 51%; specificity = 94%. Antinuclear antibody test positive; sensitivity = 99%; specificity = 49%. Immunologic disorder: Positive anti-Smith, anti-ds DNA, antiphospholipid antibody, or false positive serological test for syphilis; sensitivity = 85%; specificity = 93%. Presence of anti-ss DNA in 70% of cases (though also positive with rheumatic disease and healthy persons). Neurologic disorder: Seizures or psychosis; sensitivity = 20%; specificity = 98%.Other than the ACR criteria, people with lupus may also have:
Fever (over 100 °F/ 37.7 °C)
Extreme fatigue
Hair loss
Fingers turning white or blue when cold (Raynauds phenomenon)

Criteria for individual diagnosis
Some people, especially those with antiphospholipid syndrome, may have SLE without four of the above criteria, and also SLE may present with features other than those listed in the criteria.Recursive partitioning has been used to identify more parsimonious criteria. This analysis presented two diagnostic classification trees:

Simplest classification tree: SLE is diagnosed if a person has an immunologic disorder (anti-DNA antibody, anti-Smith antibody, false positive syphilis test, or LE cells) or malar rash. It has sensitivity = 92% and specificity = 92%. Full classification tree: Uses 6 criteria. It has sensitivity = 97% and specificity = 95%.Other alternative criteria have been suggested, e.g. the St. Thomas Hospital "alternative" criteria in 1998.
The initial fever is usually followed in a few days by a single, short rise but there may be many relapses between periods without fever. The most constant symptom is pain in the legs. Recovery takes a month or more. Lethal cases are rare, but in a few cases "the persistent fever might lead to heart failure". Aftereffects may include neurasthenia, cardiac disturbances and myalgia. Pathophysiology
Bartonella quintana is transmitted by contamination of a skin abrasion or louse-bite wound with the faeces of an infected body louse (Pediculus humanus corporis). There have also been reports of an infected louse bite passing on the infection. Diagnosis
Serological testing is typically used to obtain a definitive diagnosis. Most serological tests would succeed only after a certain period of time past the symptom onset (usually a week). The differential diagnosis list includes typhus, ehrlichiosis, leptospirosis, Lyme disease, and virus-caused exanthema (measles or rubella). Treatment
The treatment of trench fever can vary from case to case, as the human body has the ability to rid itself of the disease without medical intervention. Some patients will require treatment, and others will not. For those who do require treatment, the best treatment comes by way of doxycycline in combination with gentamicin. Chloramphenicol is an alternative medication recommended under circumstances that render use of tetracycline derivates undesirable, such as severe liver disease, kidney dysfunction, in children under nine years and in pregnant women. The medication is administered for seven to ten days.