Objective: Immunophenotyping of blood lymphocytes is an important tool in the diagnosis of hematologic and immunologic disorders. Because of maturation and expansion of the immune system in the first years of life, the relative and the absolute size of lymphocyte subpopulations vary during childhood. Therefore we wished to obtain reference values for the relative and the absolute size of all relevant blood lymphocyte subpopulations in childhood. Study design:We used the lysed whole blood method for analysis of lymphocyte subpopulations in 429 blood samples from neonates (n = 20), healthy children (n = 358), and adults (n = 51). The following age groups were used: I week to 2 months (n = 13), 2 to 5 months (n = 46), 5 to 9 months (n = 105), 9 to 15 months (n = 70), 15 to 24 months (n = 33), 2 to 5 years (n = 33), 5 to 10 years (n = 35), and 10 to 16 years (n = 23).Results: Our results show that the absolute number of CD19* B lymphocytes increases twofold immediately after birth, remains stable until 2 years of age, and subsequently gradually decreases 6.5-fold from 2 years to adult age. The CD3* T lymphocytes increase 1.5-fold immediately after birth and decrease threefold from 2 years to adult age. The absolute size of the CD3*/CD4* T-lymphocyte subpopulation follows the same pattern as the total CD3 + population, but the CD3+/CD8 * T lymphocytes remain stable from birth up to 2 years of age, followed by a gradual threefold decrease toward adult levels. In contrast to B and T lymphocytes, the absolute number of natural killer cells decreases almost threefold in the first 2 months of life and remains stable thereafter. Our study also showed that changes in the absolute size of lymphocyte subpopulations are not always consistent with changes in their relative size. This demonstrates that the relative counts of lymphocyte subsets do not reflect their actual size and are therefore of limited value. Conclusion:On the basis of this study we strongly recommend that immunophenotyping of blood lymphocytes for the diagnosis of hematologic and immunologic disorders be based on the absolute rather than on the relative size of lymphocyte subpopulations. Our data can be used as age-matched reference values for blood lymphocyte immunophenotyping. (J Pediatr 1997; 130:388-93)

SummaryParaneoplastic cerebellar degeneration (PCD) is a heterogeneous group of disorders characterized by subacute cerebellar ataxia, speci®c tumour types and (often) associated antineuronal antibodies. Nine speci®c antineuronal antibodies are associated with PCD. We examined the relative frequency of the antineuronal antibodies associated with PCD and compared the neurological symptoms and signs, associated tumours, disability and survival between groups of PCD with different antibodies. Also, we attempted to identify patient-, tumour-and treatment-related characteristics associated with functional outcome and survival. In a 12-year period, we examined >5000 samples for the presence of antineuronal antibodies. A total of 137 patients were identi®ed with a paraneoplastic neurological syndrome and high titre (b400) antineuronal antibodies. Fifty (36%) of these patients had antibodyassociated PCD, including 19 anti-Yo, 16 anti-Hu, seven anti-Tr, six anti-Ri and two anti-mGluR1. Because of the low number, the anti-mGluR1 patients were excluded from the statistical analysis. While 100% of patients with anti-Yo, anti-Tr and anti-mGluR1 antibodies suffered PCD, 86% of anti-Ri and only 18% of anti-Hu patients had PCD. All patients presented with subacute cerebellar ataxia progressive over weeks to months and stabilized within 6 months. The majority of patients in all antibody groups had both truncal and appendicular ataxia. The frequency of nystagmus and dysarthria was lower in anti-Ri patients (33 and 0%). Later in the course of the disease, involvement of noncerebellar structures occurred most frequently in antiHu patients (94%). In 42 patients (84%), a tumour was detected. The most commonly associated tumours were gynaecological and breast cancer (anti-Yo and anti-Ri), lung cancer (anti-Hu) and Hodgkin's lymphoma (antiTr and anti-mGluR1). In one anti-Hu patient, a suspect lung lesion on CT scan disappeared while the PCD evolved. Seven patients improved by at least 1 point on the Rankin scale, while 16 remained stable and 27 deteriorated. All seven patients that improved received antitumour treatment for their underlying cancer, resulting in complete remission. The functional outcome was best in the anti-Ri patients, with three out of six improving neurologically and ®ve were able to walk at the time of last follow-up or death. Only four out of 19 anti-Yo and four out of 16 anti-Hu patients remained ambulatory. Also, survival from time of diagnosis was signi®cantly worse in the anti-Yo (median 13 months) and anti-Hu (median 7 months) patients compared with anti-Tr (median >113 months) and anti-Ri (median >69 months). Patients receiving antitumour treatment (with or without immunosuppressive therapy) lived signi®-cantly longer [hazard ratio (HR) 0.3; 95% con®dence interval (CI) 0.1±0.6; P = 0.004]. Patients b60 years old lived somewhat shorter from time of diagnosis, although statistically not signi®cant (HR 2.9; CI 1.0±8.5; P = 0.06).

Maternal hypothyroxinemia is a risk factor for cognitive delay in early childhood.

Antibodies to TSST-1 have a neutralizing capacity, and median levels of antibodies to TSST-1, SEA, ClfA, and ClfB are higher in persistent carriers than in noncarriers. These antibodies might be associated with the differences in the risk and outcome of S. aureus infections between nasal carriers and noncarriers.

The group of patients with Guillain-Barr'e syndrome (GBS) is very heterogenous with regard to antecedent infections, immunological parameters, clinical manifestations, and response to treatment. In this study, the presumed pathogenic factors anti-GM1 antibodies and Campylobacter jejuni infections were related to the clinical characteristics. Serum from 154 patients with GBS, 63 patients with other neurological diseases (OND), and 50 normal controls (NC) were tested for the presence of antibodies against GM1 and C. jejuni. Anti-GM1 antibodies were detected in 31 (20%) GBS patients, 5 (8%) OND patients, and in none of the NC. Evidence for a recent C. jejuni infection was found in 49 (32%) GBS patients and less often in OND patients (11%) or NC (8%). In GBS patients, the presence of anti-GM1 antibodies was significantly associated with C. jejuni infections. The subgroup of GBS patients with anti-GM1 antibodies suffered more often from a rapidly progressive and more severe neuropathy with predominantly distal distribution of weakness, without deficits of cranial nerves or sensory disturbances. The subgroup with C. jejuni infection also more often had a severe pure motor variant of GBS. Recovery of the patients with anti-GM1 antibodies and C. jejuni infections was not as good after plasma exchange compared with intravenous immunoglobulins.