Worse Urinary Findings after Stimulating Tonsils in Patients with IgA Nephropathy

Hideaki Yamabe, MD, Second Department of Internal Medicine, Hirosaki University School of Medicine, 5 Zaifucho, Hirosaki 036 (Japan) Dear Sir, Although the pathogenesis of IgA nephropathy still remains uncertain, the IgA-type immune complex is presumed to be one of the causative factors of this disease [1]. The predominant deposition of IgA in the glome-ruli makes us consider the role of mucosal immunity in the pathogenesis because of the importance of IgA in immune defense mechanism at the mucosal sites. It is well known that IgA nephropathy patients often show gross hematuria or deteriorated urinary findings after upper respiratory tract infection such as rhinopharyngitis or tonsillitis and it is supposed that the pathogen that causes the preceding infection may play a role as an antigen. It is also suggested that abnormalities of the secretory immune system may exist in IgA nephropathy patients. Several investigators reported the increase of tonsillar IgAse-creting cells [2], the increase of IgA concentration in pharyngeal washings [3] and elevated salivary IgA in IgA nephropathy patients [4, 5]. We speculated that chronic tonsillitis may be involved in the development of IgA nephropathy and tried to clarify the deleterious effect of mechanical tonsil stimulation on urinary findings. The subjects were 62 patients with IgA nephropathy (35 male and 27 female; mean age 26.3 years, age range from 14 to 55 years) and 20 patients with other renal diseases (12 male and 8 female; mean age 29.6 years, age range from 15 to 54 years). Other renal diseases included 11 cases of mesangial pro-liferative glomerulonephritis without IgA deposition, 4 membranous nephropathy, 3 acute glomerulonephritis and 2 idiopathic renal bleeding. Each tonsil was stimulated for 5 min with the Tonsil Provocator (Nagashima Medical Instruments, Tokyo, Japan) producing an ultra shortwave to 40.68 MHz. The probe was put into the mouth until directly attached to the tonsil. A serial quantitative analysis of proteinuria and hematuria was evaluated before, 3 and 24 h after the stimulation. When