Imbalance of helper and suppressor T lymphocytes in malignant non-Hodgkin lymphomas: an in situ morphometric analysis.

The number and distribution of reactive T cells within 100 malignant B-cell lymphomas were evaluated in situ by immunomorphometry using stereological methods. Findings were related to histological and clinical parameters. A mean of 2 X 10(4) reactive T cells/microliter tumour tissue was found. This corresponds to 40% of the T-cell content of normal lymphatic tissues. The distribution of reactive T cells within the tumours was diffuse except for centroblastic/centrocytic lymphomas. When evaluating the different histological entities a correlation between number of helper T cells, T helper:T suppressor (TH:TS) ratio and histological subgroups emerged, particularly in non-Hodgkin lymphomas of low-grade malignancy. The highest ratio was found in prognostically favourable subgroups, CLL (2.7 +/- 0.3) and tumour areas of centroblastic/centrocytic lymphomas (2.9 +/- 0.4). In contrast, a significantly lower ratio was found in centrocytic lymphomas (1.4 +/- 0.3) corresponding well to the worst prognosis of this subgroup. The relationship between the number of helper T cells in tumour tissues, TH:TS ratio and prognosis was confirmed and extended by the evaluation of clinical data. It could be shown that, independently of histological criteria, a close correlation exists between the number of T cells, particularly T helper cells within the tumour, TH:TS ratio and clinical course. Patients with a favourable course had 1.4 X 10(4) T helper cells/microliter tumour tissue compared to only 0.8 X 10(4) for patients with an unfavourable clinical course (p less than 0.01); the TH:TS ratio was 2.8 for the favourable and 1.8 for the unfavourable group, respectively (p less than 0.04). In contrast, neither treatment nor tumour stage had a clear-cut influence on the extent of T-cell infiltration.