Changes in the immune response against BCP 54 following corneal transplantation in man.

Bovine corneal protein (BCP) 54 is the major soluble protein of the cornea. Immune responses against this protein can be observed in patients with corneal disease or inflammatory disease of the anterior chamber of the eye. We wanted to determine whether an immune response against this corneal protein plays a role in corneal transplantation. A cell-mediated immune response against BCP 54 was therefore determined in 46 patients prior to and on several occasions during the first year following corneal transplantation. The presence of an anti-BCP 54 response before transplantation was not associated with any clinical parameters or with rejection following transplantation. The highest frequency of positive responses was observed three months after transplantation. Transplantation may have stimulated a temporary immune response against a previously sequestered antigen, but this tissue-specific immune response did not necessarily lead to rejection. Therefore, no prognostic value can be attributed to the anti-BCP 54 response.

Cellular and humoral anticorneal immune response in corneal transplantation.

Immunologic responses play a role in the rejection process of corneal transplants. Both histocompatibility antigens and tissue-specific antigens may be potential targets for such an immune response. To identify relevant responses, the humoral immune response against corneal tissue and the cellular immune response against one specific corneal protein were determined in patients before and after corneal transplantation. The results were compared with known risk factors for corneal transplantation, but no correlations were observed. A conversion from negative to positive in cellular immune response against the cornea-specific protein was seen in patients who had experienced an inflammatory episode during the time interval between measurements. The anticorneal protein response may therefore be the result of an intraocular inflammatory response, but not a prognostic factor to help predict the patients at risk for rejection.

Genetic and clinical determinants for the T cell mediated immune response against the cornea specific protein BCP 54.

T cell mediated immune responses against the cornea specific protein BCP 54 have been observed in patients with uveitis, Fuchs' heterochromic cyclitis, and corneal disease. The pathophysiological role of this anti-BCP 54 response in corneal disease is not known. In order to ascertain whether the presence of such an immune response is related to the corneal disease itself or related to genetic influences, the anti-BCP 54 response was determined in 104 patients with severe corneal disease, using a monocyte migration inhibition assay. The results were compared with the presence of a variety of ocular parameters as well as with the distribution of HLA antigens in these patients. While only 7% of healthy controls responded to BCP 54, 37% of the patients showed a positive response (p = 0.002); in particular, patients with previous graft rejection, non-herpetic keratitis, and bullous keratopathy reacted against BCP 54. No relation with known risk factors for corneal transplantation, such as corneal neovascularisation, was observed. No significant association with the presence of any of the HLA antigens was observed. It was concluded that the main inducer of an anti-BCP 54 response is corneal disease itself, and that the presence of corneal disease is able to break the immunological privilege typical of normal corneas.

Ultrasonographic fetal spleen measurements in red blood cell-alloimmunized pregnancies.

OBJECTIVES: This study was performed to evaluate the possible relationship between fetal spleen size and fetal hemoglobin levels and to assess the predictive value of ultrasonographically measured fetal spleen size as an estimate of the severity of fetal hemolytic anemia. STUDY DESIGN: Before 85 consecutive fetal blood samples in 28 red blood cell-alloimmunized pregnancies ultrasonographic fetal spleen measurements were performed. Results were compared with our own longitudinally derived reference ranges and were correlated with fetal hemoglobin deficit. RESULTS: A significant positive correlation was found between spleen perimeter and fetal hemoglobin deficit. The ultrasonographic finding of splenomegaly correctly predicted severe fetal anemia (hemoglobin deficit > 5 SD from normal mean) in 44 of 47 cases, a positive predictive value of 94%. At first transfusion all fetuses showing splenomegaly were severely anemic. CONCLUSION: Fetal spleen measurements may be a useful adjunct to ultrasonographic evaluation in the management of severe red blood cell-alloimmunized pregnancies.