Fibroblastic rheumatism: clinical, histological, immunohistological, ultrastructural and biochemical study of a case

Abstract

We report a case of fibroblastic rheumatism (FR). Only eight other cases of this recently described entity have been reported previously. FR is characterized by polyarthralgia and joint stiffness without joint destruction, associated with cutaneous nodules and sclerodactyly. Histology shows an increase in the number of fibroblasts and marked dermal fibrosis. Rheumatological and skin manifestations may improve with corticosteroid therapy. In our patient, immunohistochemical studies of involved and uninvolved skin showed an increase in fibronectin and tenascin deposition. In the dermis, the hyperplastic cells had phenotypic features of muscle, suggesting myofibroblastic differentiation. Ultrastructural study showed an increase in active fibroblastic cells with features of myofibroblasts. A hyperproliferative capacity was observed in fibroblasts cultured from involved skin. Biochemical studies of the production of collagen and non-collagen proteins were performed on these cultured cells, and showed a reduction in collagen and non-collagen protein synthesis by FR fibroblasts. Thus, FR appears to differ from other fibrotic skin diseases such as scleroderma, in that dermal fibrosis may be due predominantly to fibroblast proliferation with myofibroblastic differentiation without any increase in collagen synthesis.

Fibroblastic rheumatism: A report of 4 cases with potential therapeutic implications

“…Both exogenous and endogenous factors may drive the observed fibroblast proliferation. 17 Infectious triggers may play a role in some cases, given that two of our patients experienced onset of disease in the setting of recent infections: an upper respiratory tract infection with positive antistreptolysin O titer in case 1 and newly diagnosed hepatitis C in case 4. In the latter case, the exact chronologic association of exposure to hepatitis C and onset of FR symptoms is not clear.…”

“…The SMA positivity present in one case had a myofibroblastic pattern of staining consistent with previous in-depth ultrastructural and immunohistochemical studies supporting a fibroblast/myofibroblast cellular origin in FR. 11,17,19 The absence of neutrophils or evidence of vascular damage argue against a diagnosis of erythema elevatum diutinum. The more cellular lesions have some resemblance to nephrogenic systemic fibrosis but the clinical setting is entirely different.…”

“…[5][6][7][8][9][10][11][12][13][14][15] The clinical differential includes other conditions with associated skin nodules and rheumatologic symptoms such as rheumatoid arthritis, multicentric reticulohistiocytosis, and nodular scleroderma, which can all be excluded on the basis of laboratory testing and histology. 16,17 To avoid permanent joint deformity and disability, early diagnosis and institution of treatment are crucial. Histologically, the differential diagnosis includes entities such as scar, fibromatosis, nuchal fibroma, erythema elevatum diutinum, and nephrogenic systemic fibrosis.…”

“…[1][2][3][4][5][6][7][8][9][11][12][13][14][15]17,[19][20][21][22][23][24][25][26] Nine of these 28 cases, or 31%, have involved pediatric patients. 5,11,21,22,24 Although earlier literature suggested a female predominance, 17 based on the current data 60.7% have occurred in males.…”

Fibroblastic Rheumatism

“…4 Despite several different therapies used, the course of FR is often progressive with most patients developing varying degrees of flexion deformities either as a result of sclerodactyly or a destructive arthropathy. [2][3][4][5][6] This tendency makes recognition and emphasis on early treatment of the disease before progression to permanent disabilities especially important.…”