General symptoms such as fever, weight loss, anorexia, adynamia, lymphadenopathy and myalgia, can occur in HIV and SLE, in several phases of these diseases [1] [4] .

Arthralgia and arthritis with varied patterns (mono, oligo or polyarticular) may occur in both SLE and HIV [1] [2] [3] [4] [5] .

Anemia, leukopenia, lymphopenia and hypergammaglobulinemia are frequent manifestations in both diseases [1] [4] .

All types of serositis (pleuritis, pericarditis and peritonitis) have been described in HIV and are relatively common manifestations in SLE [1] [2] [3] [4] [5] .

Psychoses, peripheral neuropathies, focal deficits, and stroke are neurological abnormalities shared by both diseases [6] .

Oral ulcer and malar rash are classic manifestations of SLE, but may occur in HIV. Photosensitivity, characteristically described in SLE, is a common symptom in HIV and is generally considered a late manifestation in the course of infection.

The occurrence of discoid lupus erythematosus in HIV patients seems to be quite rare but has already been described in the literature [2] [7] [8] .

SLE and HIV present similarities to renal manifestations: both may present hematuria, proteinuria, frank nephropathy and even renal failure [6] .

HIV-associated nephropathy (HIVAN) occurs most commonly in black patients and is characterized by nephrotic proteinuria, which progresses rapidly to renal failure in most cases [9] . Histologically, HIVAN is caused by focal and segmental glomerulosclerosis. Less frequently, membranoproliferative glomerulonephritis, IgA nephropathy, and thrombotic microangiopathy have been reported in patients with HIV-associated nephropathy [6] . Lupus nephritis appears to present a more varied clinical picture when compared to HIVAN and histologically there is deposition of immunocomplexes, causing the various patterns of lupus nephritis [10] [11] [12] .

In 1999, Chang et al. Described 4 cases of patients with concomitant SLE and HIV who had renal changes. They were submitted to biopsy showing changes compatible with lupus nephritis in all of them. However, in 2 subjects there were still histological changes suggestive of HIVAN (tubular microcysts, podocyte hypertrophy and glomerular basement membrane collapse) and the authors concluded that there was an overlap of lupus nephritis and HIV-associated nephritis. The same authors reviewed another series of previously published cases in which 7 patients with HIV and SLE had renal manifestations that were diagnosed as follows after histological study: 1 patient with class III lupus nephritis and 1 patient with class IV nephritis, 2 patients with nephritis class V, 1 patient with HIV-associated nephritis and 2 patients with mixed findings of lupus nephritis and HIVAN. In these two series there was a high proportion (55%) of pediatric cases (vertical transmission of HIV), a fact that raises doubts about the mechanisms involved in the genesis of nephritis in this population [6] . This trend of onset of nephritis in the pediatric population with SLE and perinatal HIV transmission has also been described in other publications [1] [11] .

Another form of nephropathy that may cause great difficulties in the differential diagnosis with SLE: lupus-like nephritis has been described in HIV infection. It is a form of glomerulopathy with presence of immunocomplexes deposits and complement in immunofluorescence, in the absence of other clinical or laboratory manifestations of lupus [13] [14] . This form of nephritis has been described in the early stages of HIV infection, soon after seroconversion, and has been reported even in transplanted kidney of HIV patients [15] [16] .

8) Other manifestations

SICCA syndrome, ocular and pulmonary manifestations, thromboembolic phenomena, can manifest in a similar way in both SLE and HIV [1] [2] [3] [4] [5] [17] .

Table 2 shows a summary of the clinical manifestations of the two diseases.

Treatment with immunosuppressants required in cases of SLE may favor the onset of manifestations of a previously undiagnosed HIV infection or worsen the course of the disease in those known to be HIV positive. This fact probably results from increased viral replication [4] [7] . Alonso and Lozada described a case of a SLE patient who developed positive HIV serology but with an undetectable viral load. After pulse therapy with cyclophosphamide due to recurrent SLE crises, there was a marked increase in viral load which was reversed with suspension of the drug [18] .

Another aspect to consider is treatment related to HIV infection. Since the beginning of highly active antiretroviral therapy (HAAV), there has been great progress in the treatment of HIV-infected patients with improved morbidity and mortality. However, after recovery of immunity from treatment, new symptoms known as “immune restoration inflammatory syndrome” (IRIS) have been observed, including symptoms and new diagnoses of autoimmune diseases such as SLE . Calabrese al al described, in a literature review, 4 new cases of SLE after HAAV [19] .

An additional approach already published in the literature is that the emergence of SLE in advanced stages of HIV seems to favor a milder course of lupus evolution, probably due to the role of CD4 + T lymphocytes in its pathogenesis [5] .

HIV infection in SLE patients appears to have a favorable impact on the progression of autoimmune disease. Several cases in the literature have described improvement and even remission of autoimmune disease after the onset of HIV. On the other hand, after initiation of HAAV therapy and improvement of the immune status, reactivation of latent symptoms or signs of SLE activity may occur [1] [4] .

Because it is an association that is still rare and may present similar manifestations, concomitant signs of SLE and HIV generate great difficulties in management. Several case reports show different views of how HIV can interfere with the course and manifestations of SLE and vice versa [2] . In general, the symptoms of the two conditions may coexist at the time of diagnosis or manifest in the course of evolution, and it is sometimes a real dilemma to distinguish the cause.