BACKGROUNDAcute diffuse glomerulonephritis is one of the most prevalent causes of glomerulonephritis worldwide. Children of preschool age are the most affected age group, being rare in adults over 40 years old. Treatment is symptomatic and the prognosis is favorable in most cases. CASE REPORTFemale patient, 42 years old, in 2019 started with a recurrent urinary infection. During the investigation, the presence of proteinuria was evidenced, an ANA was requested, which was reactive and a renal biopsy was indicated, but not performed at the time due to loss of follow-up. In January 2020, she developed malar rash, photosensitivity, alopecia, inflammatory rhythm arthralgia in metacarpophalangeal and proximal interphalangeal joints. After an irregular external follow-up period and with a report of shortterm use of hydroxychloroquine and methotrexate, in August 2021 she was referred to our service. When the diagnostic hypothesis of systemic lupus erythematosus (SLE) was raised, tests were requested for diagnostic investigation, with fine speckled nuclear ANA 1:160, C3 hypocomplementemia, reagent anticardiolipin IgM and 24-h proteinuria of 957 mg. Due to the diagnosis of SLE with persistent proteinuria without loss of renal function, it was decided to perform a renal biopsy to better elucidate the condition before instituting immunosuppression. The biopsy showed 23 glomeruli with mild to moderate hypercellularity, with reduced capillary lumen and occasional neutrophils in these areas, 2 of them with a focus of fibrinoid necrosis. The immunohistochemistry showed as alteration the presence of complement, positive C3 fraction 3+/3+ with coarse granular pattern, of global and diffuse distribution in capillary loops. The morphological findings associated with the immunofluorescence exam correspond to acute diffuse intracapillary glomerulopathy (post-streptococcal glomerulonephritis). Since the patient meets the criteria for SLE, with proteinuria, but with renal biopsy not suggestive of lupus nephritis, but of another pathology (ADGN), it was decided to introduce methotrexate 12.5 mg/week, prednisone 20 mg/day due to cutaneous activity and articulate. The patient evolved with resolution of proteinuria and normalization of C3 with the instituted treatment. CONCLUSIONThe presence of proteinuria in SLE patients should draw our attention to one of the most serious complications of this disease, which is lupus nephritis. However, its differential diagnosis is extensive and renal biopsy should be performed whenever possible, since other diagnoses may not require immunosuppression.

Amyloidosis can mimic or occur concomitantly with several rheumatological diseases, and it is necessary to pay attention to this pathology as a differential diagnosis of immune-mediated diseases.

BACKGROUNDTakayasu's arteritis (TA) is a rare, chronic inflammatory disease, more common in women of reproductive age, which affects the aorta and its branches and can cause stenosis, occlusion and aneurysms. The pathophysiology is not fully understood, but there is a T cell-mediated immune response that results in granulomatous inflammation in all layers of the vessel. Enteropathic arthritis is a spondyloarthritis (SpA) that occurs in patients with inflammatory bowel diseases (IBDs) and other gastrointestinal diseases and treatment depends on whether the involvement is axial or peripheral. Large granular lymphocyte leukemia (LGL) is a rare lymphoproliferative disease with expansion of CD8+ cells, which can coexist with autoimmune diseases in around 35.7%. Studies describe that 1/5 of patients with TA have extravascular manifestations, such as SpA and IBD. A study in South Korea included 268 patients with TA, 19% had extravascular manifestations: arthritis (11.9%), sacroiliitis (7.1%) and IBD (2.6%). It was also shown that sacroiliitis in patients with TA differs from the general population, being more common in women and presenting a low incidence of positivity for HLA-B27. To date, the pathophysiology between TA and IBD is unclear, but HLA haplotypes (HLABw52 and DR2) are common in both. In 1998, the first cases of coexistence of UC, ankylosing spondylitis (AS) and TA were described. A study in a Norwegian population showed a prevalence of SpA and Crohn's disease (CD) among TA patients of 7% and 8%, respectively. Farrant et al. showed that only 29 cases were reported in the literature of patients with TA and CD. Another study found 7-9% of IBD cases in TA patients. Guzel et al. observed 69 patients with TA and of these, 20.3% had SpA. CASE REPORTFemale patient diagnosed with TA at 25 years old, diagnosed with UC at 53 years old, evolved with left proximal interphalangeal arthritis. She had sacroiliitis on MRI and HLA B27 positivity with a diagnosis of peripheral SpA, and methotrexate (MTX) was started. Currently, at age 63, she evolved with lymphocytosis and neutropenia with a diagnosis of LGL. Hematology was chosen for maintaining MTX indefinitely and the patient maintained control of the condition. CONCLUSIONThe literature describes an association between TA, IBD and SpA with still unknown pathophysiology that relates these diseases; however, there seems to be a connection between them as we find more and more cases described, and these associations should always be remembered.

No abstract

BACKGROUNDDifferent studies demonstrate an association between autoimmune phenomena and rheumatic disorders with human immunodeficiency virus (HIV) infection, with reports of musculoskeletal involvement in up to 72% of cases, in addition to increasing the risk for bone mineralization disorders. Spondyloarthritis is among the most prevalent joint manifestations in the population of HIV-infected patients, with the most prevalent conditions being: arthralgias (45%), reactive arthritis (5-10%), psoriatic arthritis and HIV-associated arthritis (< 10%), the latter may be similar to rheumatoid arthritis (RA). Its triggering mechanisms have not yet been clarified and the clinical course is usually more severe. Some studies also showed an association of these patients using antiretroviral therapy (ART) with higher rates of hyperuricemia when compared to healthy individuals with similar risk factors. CASE REPORTMale, 70 years old, diagnosed with acquired immunodeficiency syndrome in 1986, being started on ART since then, with an undetectable viral load. He developed a condition of chronic inflammatory polyarthralgia in the proximal interphalangeal (PIP), metacarpophalangeal (MCP) and wrists, bilaterally, with morning stiffness. Physical examination showed thickening of the 3 rd right PIP and bilateral 2 nd and 3 rd MCP, in addition to Heberden and Bouchard's nodules, and diagnostic hypotheses of HIV-related arthritis, RA and osteoarthritis (OA) of the hands were performed. Laboratory tests showed negative anti-CCP and rheumatoid factor, 5.7 uric acid and X-ray of the hands with hooked osteophyte in the 3 rd left MCP, bone sclerosis, reduction of the interarticular space in the 2 nd and 3 rd MCP bilateral and rhizarthrosis. Therapy with hydroxychloroquine and prednisone was initiated and subsequently associated with sulfasalazine due to the refractoriness. Bone mineral densitometry showed osteoporosis and lumbar spine X-ray with L1 fracture, and alendronate was started. A joint ultrasound was performed which showed synovitis and osteodegenerative process in the 3 rd MCP on the right and on the left synovitis with power Doppler grade I in the 2 nd MCP associated with significant osteophytosis and the presence of intrasynovial calcified tophi in the 2 nd and 3 rd MCP, with a new hypothesis of microcrystalline disease being performed, probable tophaceous gout, in addition to secondary OA. CONCLUSIONRheumatological manifestations are significantly prevalent in the population living with HIV and using ART, presenting a clinical picture and evolution different from the general population, requiring greater attention to differential diagnoses and individualized treatment.