Detection of antigenic substances in patients with IgA nephropathy

Is a legacy effect possible in IgA nephropathy?

The term 'legacy effect'--a memory of a treatment which produces benefits long after the cessation of the intervention--was adopted for the first time to describe the benefits of early and strict control of diabetes on cardiovascular complications. The search for a similar effect for early treatment of immune-mediated renal diseases, interrupting some self-amplification loops of the pathogenetical immunological mechanisms and leaving a permanent memory, is fascinating. Some recent reports suggest a long-term beneficial or legacy effect of early treatment of IgA nephropathy after a randomized controlled trial (RCT) using mycophenolate mofetil, methylprednisolone pulses or steroid/immunosuppressive multiple therapy, or prolonged steroid doses associated with tonsillectomy. Long-lasting effects of treatments are more likely to be achieved in early stages of IgA nephropathy, when mesangial proliferative or endocapillary hypercellular lesions are pre-eminent over sclerosis, and when proteinuria is not massive, above all in young patients. The long-term results considered are relevant, but have the counterpart of the risk of drug toxicity or side effects, which are particularly undesired in patients with a mild disease. Hence, there is interest for drugs targeting the intestinal mucosal immunity with a little systemic effect, aimed at interrupting the initial pathogenetical mechanism. The possibility of modulating anti-inflammatory regulatory T cells by modifying inducible enzymes is another fascinating field of future research.

Involvement of tonsils in IgA nephropathy

This study was intended to clarify the involvement of tonsils in the pathogenesis of IgA nephropathy. In 62 patients with IgA nephropathy and 20 patients with other renal diseases, their tonsils were stimulated by an ultra short wave. Forty of 62 patients with IgA nephropathy (65%) showed a deterioration of urinary findings after the stimulation compared with six of 20 patients with other renal diseases (30%). Previous episodes of gross hematuria following upper respiratory tract infections existed in 17 of 40 patients (Group A) who showed a deterioration of urinary findings after tonsil stimulation (43%) as against in four of 22 (Group B) without the deterioration (18%). The level of serum secretory IgA was higher in Group A than in Group B. It is suggested that chronic tonsillitis may play an important role in the development of IgA nephropathy. Thirty-six patients received tonsillectomy from 1980-2002. The frequency of gross hematuria at upper respiratory infection decreased in 56% of the patients The amount of urinary protein decreased in 33% of the patients and RBC counts decreased in 56% of the patients Eight patients with tonsillectomy were followed up longer than 16 years Two of them went to hemodialysis and five of them showed no urinary abnormalities at present. The effect of tonsillectomy in the long term was not clarified in this study.

IgA antibodies to dietary antigens and lectin-binding IgA in sera from Italian, Australian, and Japanese IgA nephropathy patients

We studied serum IgA as antibodies to dietary antigens (Ag), as lectin-binding molecules, and as conglutinin-binding immune complexes (IgAIC) in people from geographical areas in which IgA nephropathy (IgAGN) is particularly frequent. Sera from 63 Italian, 21 Australian, and 25 Japanese patients affected by IgAGN and 24 Italian, 20 Australian, and 40 Japanese healthy controls were studied. Increased values of IgAIC were detected in 42.8% of Italian patients, while only in 23.8% and 8% of Australian and Japanese patients, respectively. Mean values were significantly increased only in Italian patients (P less than 0.0001). Positive values of IgA antibodies against dietary Ag had variable prevalences, but again Italian patients showed the highest frequency, from 19% to 28.5% versus 0 to 38% in Australians and 0 to 16% in Japanese. Mean values of these antibodies were not significantly increased in any patient groups in comparison to the corresponding healthy populations. However, patients with elevated values of IgAIC had significantly higher serum concentrations of antibodies to alimentary components and a linear correlation was found between IgAIC and some IgA antibodies to food components. The relationship between these two series of data was particularly evident for Italian and Australian IgAGN patients. Moreover, the patients with positive data tended to have a cluster of increased levels of IgA antibodies against several alimentary Ag at the same time. A linear correlation was evident between values of IgA antibodies to gluten fractions and to heterologous albumins. None of these correlations was evident among healthy controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Specific binding of circulating IgA antibodies in patients with IgA nephropathy

Detection of circulating IgA antibodies which are specific in patients with IgA nephropathy is described. Freeze and thawed extracts of pharyngeal cells obtained from patients with IgA nephropathy, other glomerular diseases, and healthy adults were cultured with fibroblasts such as Vero or Hel cells at 37 degrees C for 2 weeks. Serum samples were obtained from these patients and healthy adults. The cultured fibroblasts were fixed on slide glasses, and then incubated with the serum samples from the same or other patients with IgA nephropathy. The cells were stained with FITC-labeled heavy-chain specific anti-human IgA antiserum and then examined with a fluorescent microscope. It was demonstrated that the IgA antibodies in sera obtained from patients with IgA nephropathy or HSP nephritis were bound with the nuclear regions of such fibroblasts. It was suggested that IgA antibodies in sera could be bound with some antigenic substances which were transferred from pharyngeal cells of patients with IgA nephropathy to fibroblasts in vitro.