Effects of low-dose, noncytotoxic, intraarticular liposomal clodronate on development of erosions and proteoglycan loss in established antigen-induced arthritis in rabbits.

OBJECTIVE: To assess the clinical and histologic effects of an intraarticular application of low-dose (non-cytotoxic) liposomal clodronate in established antigen-induced monarthritis (AIA) in rabbits. METHODS: AIA was monitored by assessments of joint swelling, C-reactive protein levels, and radiographic changes in 17 NZW rabbits for 8 weeks during the course of weekly intraarticular injections of liposomal clodronate (0.145 mg/injection, low dose) or "empty" liposomes. The contralateral knee was injected with liposome buffer alone as the control. End-point analyses included macroscopic joint examination, immuno- and TUNEL staining, Safranin O staining/microspectrophotometry, and tumor necrosis factor alpha (TNFalpha) convertase enzyme (TACE) inhibition assay. RESULTS: Liposomal clodronate-treated rabbits showed a reduction and delay in joint swelling during the first 3 injections. Expression of matrix-bound (solubilized) TNFalpha, lining cell hyperplasia, and levels of RAM-11+ macrophages were low in the synovium of the liposomal clodronate treatment group, but the proportion of apoptotic lining cells was not affected. The radiologic score was low at the end of weeks 2 and 4, but at 8 weeks, no difference, compared with controls, was found in pannus formation or in the extent of joint erosion; also, joint swelling was higher than before initiation of treatment. Injections of liposomal clodronate prevented cartilage proteoglycan loss, which was significant in the superficial zone only. TACE activity was not inhibited by clodronate. CONCLUSION: Liposomal clodronate had temporary antiinflammatory and antierosive effects on established AIA in rabbits. Over the long-term, the loss of cartilage proteoglycans was halted. This observed treatment effect may be related to the inhibition of TNFalpha production and processing in the synovium.

Tuberculosis of the colon in a kidney transplant patient.

A 58-year-old woman experienced recurrent fever episodes after kidney transplantation. She was treated with antibiotics because of suspicion of staphylococcus infection. Abdominal pain combined with haemorrhagic diarrhoea occurred eight months after transplantation. A barium enema revealed a stenotic process in the middle part of the ascending colon mimicking carcinoma, and hemicolectomy was consequently performed. Histological examination revealed tuberculosis with little granuloma formation and abundant acid-fast tubercle bacilli in the mucosa and submucosa, and only slight perigranulomatous reactions. The patient was successfully treated with triple antituberculous chemotherapy without deterioration of allograft function. Tuberculosis should be suspected in immunosuppressed patients suffering from pyrexia of unknown origin, even when chest X-ray is normal.