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 × 10 4 reactive T cells/μI 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 (T H :T S ) ratio and histological subgroups emerged, particularly in non‐Hodgkinlymphomas 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, T H :T S 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, T H :T S ratio and clinical course. Patients with a favourable course had 1.4 × 10 4 T helper cells/μI tumour tissue compared to only 0.8 × 10 4 for patients with an unfavourable clinical course (p<0.01); the T H :T S ratio was 2.8 for the favourable and 1.8 for the unfavourable group, respectively (p<0.04). In contrast, neither treatment nor tumour stage had a clear‐cut influence on the extent of T‐cell infiltration.